Overview Review Traffic Revenue SEO
Hosting Registration Security Technical Related

codesandbox.io

codesandbox.io is SSL secured

Free website and domain report on codesandbox.io

Last Updated: 24th April, 2025
Overview

Snoop Summary for codesandbox.io

This is a free and comprehensive report about codesandbox.io. Our records indicate that codesandbox.io is privately registered by Privacy service provided by Withheld for Privacy ehf. Codesandbox.io is expected to earn an estimated $493 USD per day from advertising revenue. The sale of codesandbox.io would possibly be worth $359,616 USD. This figure is based on the daily revenue potential of the website over a 24 month period. Codesandbox.io is insanely popular with an estimated 116,487 daily unique visitors. This report was last updated 24th April, 2025.

About codesandbox.io

Site Preview: codesandbox.io codesandbox.io
Title: CodeSandbox: Online Code Editor and IDE for Rapid Web Development
Description: CodeSandbox is an online code editor and prototyping tool that makes creating and sharing web apps faster
Keywords and Tags: angular, application, code, codesandbox, editor, end, front, frontend, ide, javascript, page, phishing, playground, popular, react, sharing, single, spa, technical information, vue, web
Related Terms: ace code editor, code editor, online code editor, php editor review php ide, rapid prototyping
Fav Icon:
Age: Over 8 years old
Domain Created: 23rd November, 2016
Domain Updated: 26th October, 2020
Domain Expires: 23rd November, 2029
Review

Snoop Score

3/5 (Great!)

Valuation

$359,616 USD
Note: All valuation figures are estimates.

Popularity

Very High
Note: Popularity is estimated.

Rank, Reach and Authority

Alexa Rank: 10,909
Alexa Reach:
SEMrush Rank (US):
SEMrush Authority Score:
Moz Domain Authority: 0
Moz Page Authority: 0

Organic vs Paid (Google Ads)

Traffic

Visitors

Daily Visitors: 116,487
Monthly Visitors: 3,545,497
Yearly Visitors: 42,517,755
Note: All visitors figures are estimates.

Visitors By Country

Revenue

Revenue

Daily Revenue: $493 USD
Monthly Revenue: $14,994 USD
Yearly Revenue: $179,803 USD
Note: All revenue figures are estimates.

Revenue By Country

SEO

Backlinks Analysis (SEMrush)

Top New Follow Links

Top Ranking Keywords (US)

Domain Analysis

Value Length
Domain: codesandbox.io 14
Domain Name: codesandbox 11
Extension (TLD): io 2
Expiry Check:

Page Speed Analysis

Average Load Time:
Load Time Comparison:

PageSpeed Insights

Avg. (All Categories) 78
Performance 78
Accessibility 96
Best Practices 80
SEO 100
Progressive Web App 36
0–49 (Fail) 50–89 (Average) 90–100 (Pass)
URL: https://codesandbox.io/
Updated: 8th June, 2021

1.23 seconds
First Contentful Paint (FCP)
87%
8%
5%

0.00 seconds
First Input Delay (FID)
99%
1%
0%

Simulate loading on desktop
78

Performance

Indicates how well the page is performing and highlights opportunities where performance may be improved for codesandbox.io. This includes details about optimizing page load times which can result in a better user experience.

Metrics

First Contentful Paint — 0.9 s
The time taken for the first image or text on the page to be rendered.
Speed Index — 0.9 s
The time taken for the page contents to be visibly populated.
Time to Interactive — 1.0 s
The time taken for the page to become fully interactive.
Total Blocking Time — 0 ms
The total blocking time is the sum of all time periods between First Contentful Paint and Time to Interactive (when task length exceeded 50ms).
Cumulative Layout Shift — 0
Cumulative Layout Shift is the measurement of visible elements collective movement within the viewport.
View Data

Other

Max Potential First Input Delay — 60 ms
Users could experience a delay when interacting with the page.
First Meaningful Paint — 0.9 s
The time taken for the primary content of the page to be rendered.
Network Requests
Below is a list of network requests that were made during page load.
URL Protocol Start Time (Ms) End Time (Ms) Transfer Size (Bytes) Resource Size (Bytes) Status Code MIME Type Resource Type
http://codesandbox.io/
http/1.1
0
40.072000119835
504
0
301
https://codesandbox.io/
h2
40.640000021085
234.7890001256
50721
149545
200
text/html
Document
https://codesandbox.io/component---src-pages-index-js-295d7b6c6efe012f5beb.js
h2
248.99400002323
288.23500010185
43941
113541
200
application/javascript
Script
https://codesandbox.io/app-708194e4ac8d35256b83.js
h2
249.2070000153
303.30400005914
110282
374955
200
application/javascript
Script
https://codesandbox.io/styles-54c093d357ad2dd09420.js
h2
249.43900015205
299.94200007059
830
248
200
application/javascript
Script
https://codesandbox.io/2-bd90970fe6bfc2665e83.js
h2
249.75600000471
324.87600017339
21487
89289
200
application/javascript
Script
https://codesandbox.io/43-488c3dabd69392009809.js
h2
250.03900006413
304.16200007312
16300
50335
200
application/javascript
Script
https://codesandbox.io/1-29920b0332c01230873e.js
h2
250.38800016046
328.80400004797
49704
157324
200
application/javascript
Script
https://codesandbox.io/webpack-runtime-38d2f4b1c7d7cb16b5cc.js
h2
250.68900012411
276.16800018586
3054
8209
200
application/javascript
Script
https://codesandbox.io/page-data/index/page-data.json
h2
251.0290001519
400.76300012879
744
179
200
application/json
Other
https://fonts.googleapis.com/css?family=Open+Sans:400|Roboto:400i,400&display=swap
h2
252.70000007004
268.70400016196
1484
6611
200
text/css
Stylesheet
https://www.googletagmanager.com/gtm.js?id=GTM-T3L6RFK
h2
259.70500009134
280.33300000243
45503
125601
200
application/javascript
Script
data
262.44700001553
262.58700015023
0
1589
200
image/svg+xml
Image
data
264.55199997872
264.67900001444
0
4469
200
image/svg+xml
Image
data
266.2700000219
266.35500020348
0
944
200
image/svg+xml
Image
data
267.8470001556
267.90800015442
0
347
200
image/svg+xml
Image
data
269.27700010128
269.32900003158
0
436
200
image/svg+xml
Image
https://codesandbox.io/static/video-e6a34ad1b9555966b2b8be018e27c2a2.png
h2
273.10800016858
368.73800004832
349978
349212
200
image/png
Image
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
h2
273.37100007571
396.47600008175
1882724
1881958
200
image/png
Image
https://codesandbox.io/static/phone-48c67ab1b26fae0f28d4cbcfe103ddb9.png
h2
273.50700017996
342.57200011052
83073
82311
200
image/png
Image
https://codesandbox.io/static/danilowoz-8dc7e702f75beb452da0a562b5233fe6.jpg
h2
273.7700000871
305.79700018279
13664
12899
200
image/jpeg
Image
https://codesandbox.io/static/sid-c01f392777ec43b1ef66c73fba86e223.jpg
h2
274.27900000475
352.59200003929
56477
55712
200
image/jpeg
Image
https://codesandbox.io/static/christian-a152cf4260859450fad84281ca0e9ec1.png
h2
274.49400001206
347.66099997796
47994
47232
200
image/png
Image
https://codesandbox.io/static/tamas-e1b8d4ad4e52bd5b4190bf5df91661c9.png
h2
274.7190000955
330.17000020482
77945
77185
200
image/png
Image
https://codesandbox.io/static/ives-7a1c194d7343d82baf75c9cd9d209513.png
h2
274.95300001465
301.46400001831
14424
13661
200
image/png
Image
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
h2
275.17700009048
367.7509999834
353766
353001
200
image/png
Image
https://codesandbox.io/static/brian-52358144e232bdf5f26b70c1c6bd9984.png
h2
275.87000001222
304.70199999399
27878
27114
200
image/png
Image
https://fonts.gstatic.com/s/roboto/v27/KFOmCnqEu92Fr1Mu4mxKKTU1Kg.woff2
h2
290.22800014354
293.52000006475
11766
11032
200
font/woff2
Font
https://playdotjs.com/
h2
351.93600016646
456.90300012939
4212
14912
200
text/html
Document
data
353.63800008781
353.72200002894
0
714
200
image/svg+xml
Image
data
355.53800011985
355.61000020243
0
434
200
image/svg+xml
Image
data
357.61300008744
357.76000004262
0
3966
200
image/svg+xml
Image
data
359.70100015402
359.82000012882
0
2375
200
image/svg+xml
Image
data
361.92700010724
362.04400006682
0
3569
200
image/svg+xml
Image
data
364.58100005984
364.73300005309
0
4993
200
image/svg+xml
Image
data
367.29399999604
367.43300012313
0
4589
200
image/svg+xml
Image
data
367.96900001355
368.13000007533
0
5065
200
image/png
Image
https://codesandbox.io/static/peggy-8e312e7d8020e9f724ba176af345e54d.png
h2
375.86800009012
403.06200017221
33495
32731
200
image/png
Image
https://codesandbox.io/static/jonnie-253e74f068f86b528dd8a7ad41a5650b.png
h2
377.40300013684
450.4939999897
16947
16183
200
image/png
Image
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
h2
377.58900015615
406.16400004365
211887
211122
200
image/png
Image
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
h2
377.75600003079
461.86600020155
1152329
1151561
200
image/png
Image
https://codesandbox.io/static/7-c37e0c5e9adae98b18b750c28fd2e1ed.png
h2
377.94100004248
415.05399998277
41333
40569
200
image/png
Image
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
h2
378.08699999005
487.75500012562
345191
344425
200
image/png
Image
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
h2
378.21600004099
486.90900020301
339934
339168
200
image/png
Image
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
h2
378.39000020176
437.02100007795
404062
403296
200
image/png
Image
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
h2
378.56800016016
413.67999999784
579597
578832
200
image/png
Image
https://codesandbox.io/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js
h2
378.74300009571
400.31200018711
1194
1239
200
application/javascript
Script
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
h2
378.90100013465
415.72300018743
34991
111704
200
application/javascript
Script
https://static.cloudflareinsights.com/beacon.min.js
h2
379.04100003652
402.10200008005
5553
13614
200
text/javascript
Script
https://codesandbox.io/static/video-fe2b0a3ea133c28d5a99cfc0ed2313ff.mp4
428.46200009808
1054.3160000816
0
0
-1
Media
data
434.47600002401
434.53199998476
0
1303
200
image/png
Image
data
434.6539999824
434.69400005415
0
950
200
image/png
Image
data
434.78500004858
434.82100008987
0
787
200
image/png
Image
https://www.google-analytics.com/analytics.js
h2
509.52200009488
512.98000011593
20199
49153
200
text/javascript
Script
https://cdn.amplitude.com/libs/amplitude-7.1.0-min.gz.js
h2
513.58300005086
531.49100020528
20301
61487
200
application/javascript
Script
https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.css
h2
582.28099998087
604.27700006403
6454
18975
200
text/css
Stylesheet
https://playdotjs.com/_next/static/css/625bcde5887b4a5ea898.css
h2
645.80800011754
699.46600007825
3645
10464
200
text/css
Stylesheet
https://playdotjs.com/_next/static/chunks/15.c16d2cb92e0fcc0b8e55.js
h2
646.1320000235
700.91800019145
1087
1399
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/commons.80fd155a1972871b5a38.js
h2
646.45300013945
718.58700015582
12749
34736
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/13.bdf70fa0b0f4d5bb6c56.js
h2
646.86199999414
666.6860000696
2138
3226
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/16.ef3e948cebfbdf1396c7.js
h2
647.16500020586
665.70800007321
749
228
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/17.9d2818794b33463320e3.js
h2
647.53700001165
702.71700015292
1387
866
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/18.a5f3f4b732a5f627315e.js
h2
647.80000015162
717.57800015621
1419
898
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/14.f2235007b7bf874c3a6c.js
h2
648.08700000867
715.18600010313
2147
3492
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/5.7257b3b22b17bd752e53.js
h2
648.47800019197
718.26900006272
2393
4071
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/main-e4383e021aef726550db.js
h2
648.73400004581
703.1390001066
8085
20997
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/webpack-32462ae3750b38e7d006.js
h2
648.92100007273
717.93900011107
1921
2567
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/framework.767949b9f2588a43c494.js
h2
649.26800015382
716.32800018415
44373
130886
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/pages/_app-47adf0ed776ded938e2b.js
h2
649.66600015759
742.59100016207
1288
1721
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/f63252b21a915a295187fea80c9b107d3f313aa8.99e70789e9424fc300d1.js
h2
649.91300017573
694.29200002924
4699
12154
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/pages/index-2d156e83fa2351f35751.js
h2
650.2239999827
703.71100003831
4892
11916
200
application/javascript
Script
https://5o7brbeivd-dsn.algolia.net/1/indexes/prod_sandboxes/query?x-algolia-agent=Algolia%20for%20JavaScript%20(3.33.0)%3B%20Browser%20(lite)&x-algolia-application-id=5O7BRBEIVD&x-algolia-api-key=85194a1433e4196466a0f80135439c79
http/1.1
728.548000101
1524.965000106
666
226
200
application/json
XHR
https://playdotjs.com/_next/static/jVatzZ61oHEfRoSGsdwc5/_buildManifest.js
h2
759.21200006269
777.6770000346
1147
635
200
application/javascript
Script
https://playdotjs.com/_next/static/jVatzZ61oHEfRoSGsdwc5/_ssgManifest.js
h2
759.32399998419
775.29100002721
584
76
200
application/javascript
Script
data
772.63900008984
772.6960000582
0
271
200
image/svg+xml
Image
https://www.google-analytics.com/gtm/js?id=GTM-TLB9J48&t=gtm4&cid=1506752742.1623144295
h2
825.9670000989
847.70800010301
36075
90054
200
application/javascript
Script
https://codesandbox.io/page-data/legal/privacy/page-data.json
h2
845.28500004672
970.4830001574
13155
0
200
application/json
Other
https://api2.amplitude.com/
h2
857.96100017615
1211.0260000918
234
7
200
text/html
XHR
https://www.google-analytics.com/j/collect?v=1&_v=j90&aip=1&a=166088866&t=pageview&_s=1&dl=https%3A%2F%2Fcodesandbox.io%2F&ul=en-us&de=UTF-8&dt=CodeSandbox%3A%20Online%20Code%20Editor%20and%20IDE%20for%20Rapid%20Web%20Development&sd=24-bit&sr=800x600&vp=1350x940&je=0&_u=aGDAAEADQAAAAC~&jid=1462918768&gjid=1638484579&cid=1506752742.1623144295&tid=UA-89432508-1&_gid=12961063.1623144295&_r=1&gtm=2wg621T3L6RFK&z=264175215
h2
959.92700010538
963.17500015721
618
2
200
text/plain
XHR
https://www.google-analytics.com/collect?v=1&_v=j90&a=166088866&t=event&ni=0&_s=1&dl=https%3A%2F%2Fcodesandbox.io%2F&ul=en-us&de=UTF-8&dt=CodeSandbox%3A%20Online%20Code%20Editor%20and%20IDE%20for%20Rapid%20Web%20Development&sd=24-bit&sr=800x600&vp=1350x940&je=0&ec=Page%20Interaction&ea=test&el=homepage&_u=aGDAAEADQAAAAC~&jid=&gjid=&cid=1506752742.1623144295&tid=UA-89432508-1&_gid=12961063.1623144295&gtm=2wg621T3L6RFK&z=1384194429
h2
966.86600008979
969.52500008047
602
35
200
image/gif
Image
https://stats.g.doubleclick.net/j/collect?t=dc&aip=1&_r=3&v=1&_v=j90&tid=UA-89432508-1&cid=1506752742.1623144295&jid=1462918768&gjid=1638484579&_gid=12961063.1623144295&_u=aGDAAEACQAAAAC~&z=1817623221
h2
974.90400006063
978.68200019002
691
2
200
text/plain
XHR
https://codesandbox.io/page-data/legal/privacy/page-data.json
h2
979.35100016184
1128.8590000477
13314
56507
200
application/json
XHR
https://www.google.com/ads/ga-audiences?t=sr&aip=1&_r=4&slf_rd=1&v=1&_v=j90&tid=UA-89432508-1&cid=1506752742.1623144295&jid=1462918768&_u=aGDAAEACQAAAAC~&z=1157583249
h2
983.6709999945
992.96100018546
678
42
200
image/gif
Image
https://codesandbox.io/cdn-cgi/rum?req_id=65c111deb88b0633
h2
1062.1870001778
1091.16800013
409
0
200
text/plain
XHR
https://codesandbox.io/component---src-pages-legal-privacy-js-d12ec273cfaffbab0ac0.js
h2
1131.5690001938
1164.7990001366
35159
0
200
application/javascript
Other
https://api2.amplitude.com/
h2
1734.9270000122
2089.2670000903
234
7
200
text/html
XHR
https://api2.amplitude.com/
h2
2094.6669999976
2433.581000194
234
7
200
text/html
XHR
Network Round Trip Times — 0 ms
High Network RTT (Round Trip Times) can have a large impact on performance. Providing servers geographically closer to the user could improve performance.
Server Backend Latencies — 0 ms
High server latencies indicate the server is overloaded or has a poor backend performance.
Tasks
Below is a list of the top-level main thread tasks that executed during page load.
Start Time (Ms) End Time (Ms)
244.109
8.216
258.281
18.021
284.907
55.461
340.624
35.02
375.683
5.338
398.549
27.119
425.74
9.44
447.405
16.458
466.223
9.405
481.794
16.095
501.61
5.502
508.136
13.996
531.337
57.868
606.481
42.673
651.343
5.805
658.416
10.787
672.22
91.029
769.41
14.868
784.337
30.013
814.405
17.972
832.393
6.207
857.504
6.665
887.915
45.064
938.684
6.569
949.51
23.283
1260.416
5.034
1736.322
5.898
1775.459
11.02
2096.012
5.01
4259.29
6.769
Diagnostics
Below is a collection of useful page vitals.
View Data
Metrics
Below is a collection of metrics.
View Data
Script Treemap Data
Provide as required, for treemap app.

Opportunities

Defer offscreen images
Time to Interactive can be slowed down by resources on the page. Codesandbox.io should consider lazy-loading offscreen and hidden images.
Minify CSS
Cascading Style Sheets (CSS) files can contribute to network payload sizes. Codesandbox.io should consider minifying CSS files.
Minify JavaScript
JavaScript (JS) files can contribute to network payload sizes and increase script parse times. Codesandbox.io should consider minifying JS files.
Reduce unused CSS
Dead and/or unused rules in Style Sheets (CSS) can contribute to network payload sizes. Codesandbox.io should consider removing dead rules from style sheets and deferring the loading of CSS not used for above-the-fold content.
Efficiently encode images
Unoptimized images can consume more cellular data than what is necessary.
Enable text compression
Text-based resources should be served with compression, such as gzip, deflate or brotli.
Preconnect to required origins
Resource hints, such as 'preconnect' or 'dns-prefetch', may assist in establishing early connections to important third-party origins.
Initial server response time was short — Root document took 200 ms
It is advised to keep the server response time short for the main document, because all other requests depend on it.
URL Time Spent (Ms)
https://codesandbox.io/
195.145
Avoid multiple page redirects — Potential savings of 190 ms
Redirects can cause additional delays before the page can begin loading. Codesandbox.io should avoid multiple or unnecessary page redirects.
URL Time Spent (Ms)
http://codesandbox.io/
190
https://codesandbox.io/
0
Preload key requests
Key requests can be preloaded by using '<link rel=preload>'. Codesandbox.io should consider using '<link rel=preload>' to prioritize fetching resources that are currently requested later in page load.
Use video formats for animated content
Large GIFs are inefficient for delivering animated content. It is recommended to use MPEG4/WebM videos for animations and PNG/WebP for static images instead of GIF.
Remove duplicate modules in JavaScript bundles
Ensure that no duplicate JavaScript modules from bundles exist to reduce bytes consumed by network activity.
Avoid serving legacy JavaScript to modern browsers — Potential savings of 34 KiB
Polyfills and transforms enable legacy browsers to use new JavaScript features. For bundled JavaScript it is recommended to adopt a modern script deployment strategy using module/nomodule feature detection. This will reduce the amount of code shipped to modern browsers.
URL Potential Savings (Bytes)
https://codesandbox.io/1-29920b0332c01230873e.js
10648
https://codesandbox.io/app-708194e4ac8d35256b83.js
10638
https://codesandbox.io/43-488c3dabd69392009809.js
6613
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
6449
https://playdotjs.com/_next/static/chunks/commons.80fd155a1972871b5a38.js
61
https://cdn.amplitude.com/libs/amplitude-7.1.0-min.gz.js
55
Preload Largest Contentful Paint image
It is recommended to preload images used by LCP elements, to improve LCP time.

Diagnostics

Uses efficient cache policy on static assets — 4 resources found
Codesandbox.io can speed up repeat visits by increasing the cache lifetime, which is essentially how long before a cached copy expires.
URL Cache TTL (Ms) Transfer Size (Bytes)
https://www.google-analytics.com/analytics.js
7200000
20199
https://static.cloudflareinsights.com/beacon.min.js
86400000
5553
https://codesandbox.io/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js
172800000
1194
https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.css
604800000
6454
Avoids an excessive DOM size — 363 elements
A large DOM (Document Object Model) will increase memory usage, cause longer system calculations as well as costly layout reflows.
Statistic Element Value
Total DOM Elements
363
Maximum DOM Depth
path
14
Maximum Child Elements
body
16
Avoid chaining critical requests — 2 chains found
Below is a list of Critical Request Chains, which shows which resources are loaded with a high priority. Codesandbox.io should consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
User Timing marks and measures — 4 user timings
Make use of the User Timing API to measure an app's real-world performance during key user experiences.
Name Type Start Time (Ms) Duration (Ms)
Next.js-before-hydration
Measure
351.106
556.285
Next.js-hydration
Measure
907.391
16.56
beforeRender
Mark
907.42
afterHydrate
Mark
923.976
JavaScript execution time — 0.3 s
JavaScript (JS) execution time can be lowered by reducing the time required for parsing, compiling and executing JS. Delivering smaller JS payloads may help with this.
URL Total CPU Time (Ms) Script Evaluation (Ms) Script Parse (Ms)
https://codesandbox.io/
273.579
26.205
1.729
https://codesandbox.io/app-708194e4ac8d35256b83.js
215.6
192.667
5.947
https://codesandbox.io/1-29920b0332c01230873e.js
192.779
46.396
2.757
Unattributable
126.44
2.692
0.169
Minimizes main-thread work — 1.0 s
Main-thread work timing can be lowered by reducing the time required for parsing, compiling and executing JS. Delivering smaller JS payloads may help with this.
Category Time Spent (Ms)
Script Evaluation
443.928
Other
217.236
Style & Layout
190.459
Rendering
117.364
Script Parsing & Compilation
41.468
Parse HTML & CSS
31.281
Garbage Collection
3.185
All text remains visible during webfont loads
Make use of the font-display CSS feature, which will ensure text is user-visible while webfonts are loading.
Keep request counts low and transfer sizes small — 70 requests • 6,522 KiB
It is advised to add a budgets.json file in order to set budgets for the quantity and size of page resources.
Resource Type Requests Transfer Size (Bytes)
Total
70
6678694
Image
21
6033978
Script
30
500472
Other
12
65962
Document
2
54933
Font
1
11766
Stylesheet
3
11583
Media
1
0
Third-party
35
285198
Minimize third-party usage — Third-party code blocked the main thread for 0 ms
It is advised to either limit, remove or delay the loading of redundant third-party code which may be significantly impacting load performance.
Third-Party Transfer Size (Bytes) Main-Thread Blocking Time (Ms)
SHOW DETAILS
57494
0
SHOW DETAILS
45503
0
SHOW DETAILS
34991
0
SHOW DETAILS
21003
0
SHOW DETAILS
13250
0
SHOW DETAILS
6454
0
SHOW DETAILS
691
0
SHOW DETAILS
678
0
Lazy load third-party resources with facades
Consider replacing third-party embeds with a facade until they are required (use lazy loading).
Largest Contentful Paint element — 1 element found
The element which was identified as the Largest Contentful Paint.
Element
Where teams build faster, together
Avoid large layout shifts
Below is a list of all DOM elements that contribute to the CLS of the page.
Uses passive listeners to improve scrolling performance
Improve the page's scroll performance by marking touch and wheel event listeners as 'passive'.
Avoids `document.write()`
Avoid or limit the use of external scripts that are dynamically injected via 'document.write()' as users on slow connections will be delayed by tens of seconds.
Avoid long main-thread tasks — 1 long task found
Below is a list of the longest tasks on the main thread, which is useful when identifying the worst input delay contributors.
URL Start Time (Ms) Duration (Ms)
https://codesandbox.io/app-708194e4ac8d35256b83.js
982.01515388489
58
Avoid non-composited animations
It is recommended to avoid non-composited animations which are often janky and increase CLS.

Budgets

Performance budget
It is advised to keep the quantity and size of all network requests under the targets set by the provided performance budget.
Timing budget
It is advised to set a timing budget to monitor the performance of your site.

Opportunities

Eliminate render-blocking resources — Potential savings of 340 ms
Resources, such as JavaScript and style sheets, can block the first paint of the page. Codesandbox.io should consider delivering critical JavaScript/style sheets (JS/CSS) inline and deferring all non-critical JS/CSS.
URL Transfer Size (Bytes) Potential Savings (Ms)
https://fonts.googleapis.com/css?family=Open+Sans:400|Roboto:400i,400&display=swap
1484
230
Reduce unused JavaScript — Potential savings of 109 KiB
It is advised to remove unused JavaScript in order to reduce bytes consumed by network activity.
URL Transfer Size (Bytes) Potential Savings (Bytes)
https://codesandbox.io/app-708194e4ac8d35256b83.js
110282
59260
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
34991
27636
https://www.google-analytics.com/gtm/js?id=GTM-TLB9J48&t=gtm4&cid=1506752742.1623144295
36075
24878

Metrics

Largest Contentful Paint — 4.2 s
The timing of the largest text or image that is painted.

Opportunities

Properly size images — Potential savings of 4,382 KiB
Images can slow down the page's load time. Codesandbox.io should consider serving more appropriate-sized images.
URL Resource Size (Bytes) Potential Savings (Bytes)
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
1881958
1563967
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
1151561
893621
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
578832
449179
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
403296
312961
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
344425
267277
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
339168
263197
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
353001
249232
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
211122
163832
https://codesandbox.io/static/tamas-e1b8d4ad4e52bd5b4190bf5df91661c9.png
77185
75498
https://codesandbox.io/static/phone-48c67ab1b26fae0f28d4cbcfe103ddb9.png
82311
61785
https://codesandbox.io/static/sid-c01f392777ec43b1ef66c73fba86e223.jpg
55712
55062
https://codesandbox.io/static/christian-a152cf4260859450fad84281ca0e9ec1.png
47232
41984
https://codesandbox.io/static/peggy-8e312e7d8020e9f724ba176af345e54d.png
32731
25588
https://codesandbox.io/static/brian-52358144e232bdf5f26b70c1c6bd9984.png
27114
21065
https://codesandbox.io/static/ives-7a1c194d7343d82baf75c9cd9d209513.png
13661
12966
https://codesandbox.io/static/danilowoz-8dc7e702f75beb452da0a562b5233fe6.jpg
12899
12734
https://codesandbox.io/static/jonnie-253e74f068f86b528dd8a7ad41a5650b.png
16183
12702
https://codesandbox.io/static/7-c37e0c5e9adae98b18b750c28fd2e1ed.png
40569
4221
Serve images in next-gen formats — Potential savings of 4,144 KiB
Consider JPEG 2000, JPEG XR or WebP image formats which provide better compression than PNG and JPEG.
URL Resource Size (Bytes) Potential Savings (Bytes)
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
1881958
1225618
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
1151561
832393
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
578832
459502
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
353001
296541
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
403296
287500
https://codesandbox.io/static/video-e6a34ad1b9555966b2b8be018e27c2a2.png
349212
267134
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
344425
258543
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
339168
237126
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
211122
124788
https://codesandbox.io/static/phone-48c67ab1b26fae0f28d4cbcfe103ddb9.png
82311
59215
https://codesandbox.io/static/tamas-e1b8d4ad4e52bd5b4190bf5df91661c9.png
77185
57159
https://codesandbox.io/static/christian-a152cf4260859450fad84281ca0e9ec1.png
47232
42114
https://codesandbox.io/static/peggy-8e312e7d8020e9f724ba176af345e54d.png
32731
27795
https://codesandbox.io/static/brian-52358144e232bdf5f26b70c1c6bd9984.png
27114
22492
https://codesandbox.io/static/7-c37e0c5e9adae98b18b750c28fd2e1ed.png
40569
15837
https://codesandbox.io/static/jonnie-253e74f068f86b528dd8a7ad41a5650b.png
16183
11833
https://codesandbox.io/static/sid-c01f392777ec43b1ef66c73fba86e223.jpg
55712
9440
https://codesandbox.io/static/ives-7a1c194d7343d82baf75c9cd9d209513.png
13661
8289

Diagnostics

Avoid enormous network payloads — Total size was 6,522 KiB
Large network payloads can cost users money and are linked to long load times.
URL Transfer Size (Bytes)
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
1882724
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
1152329
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
579597
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
404062
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
353766
https://codesandbox.io/static/video-e6a34ad1b9555966b2b8be018e27c2a2.png
349978
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
345191
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
339934
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
211887
https://codesandbox.io/app-708194e4ac8d35256b83.js
110282
Image elements do not have explicit `width` and `height`
Reduce layout shifts and improve CLS by setting explicit width and height properties on image elements.
URL Failing Elements
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
Play.js
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
img
https://codesandbox.io/static/phone-48c67ab1b26fae0f28d4cbcfe103ddb9.png
img
96

Accessibility

Indicates how accessible the page is and highlights opportunities where the page can be made more accessible to users of codesandbox.io. This includes details about various page attributes that can be optimized.

Navigation

`[accesskey]` values are unique
Access keys assist users with focusing on different parts of the page. Each access key should be unique for proper navigation.
The page contains a heading, skip link, or landmark region
It is advised to provide ways to bypass repetitive content, allowing users to navigate the page efficiently.
`[id]` attributes on active, focusable elements are unique
Ensure all focusable elements have a unique id value to allow them to be visible to users of assistive technologies, like a screen reader.
No element has a `[tabindex]` value greater than 0
Although technically valid, a tabindex value greater than 0 often creates frustrating experiences for users who rely on assistive technologies.

ARIA

`[aria-*]` attributes match their roles
Avoid mismatching 'aria-*' attributes and their 'role' value, as it invalidates the attribute.
`button`, `link`, and `menuitem` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[aria-hidden="true"]` is not present on the document `<body>`
If aria-hidden=true is set on the document body, assistive technologies, like a screen reader will work inconsistently.
`[aria-hidden="true"]` elements do not contain focusable descendents
Interactive elements within an aria-hidden=true element are unavailable to users of assistive technologies, like a screen reader.
ARIA input fields have accessible names
Generic names are announced to users of assistive technologies, like a screen reader, when an input field does not have an accessible name specified.
ARIA `meter` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
ARIA `progressbar` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[role]`s have all required `[aria-*]` attributes
Some ARIA roles have required 'aria-*' attributes, which provide essential information about state and functionality.
Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
Some ARIA parent roles cannot perform their intended functions if specific child roles are not used.
`[role]`s are contained by their required parent element
Some ARIA child roles cannot perform their intended functions if specific parent roles are not used.
`[role]` values are valid
All ARIA roles require valid values to perform their intended functions.
ARIA toggle fields have accessible names
Generic names are announced to users of assistive technologies, like a screen reader, when a toggle field does not have an accessible name specified.
ARIA `tooltip` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
ARIA `treeitem` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[aria-*]` attributes have valid values
ARIA attributes cannot be interpreted with invalid values when used by screen readers and other assistive technologies.
`[aria-*]` attributes are valid and not misspelled
ARIA attributes cannot be interpreted with invalid names when used by screen readers and other assistive technologies.
ARIA IDs are unique
Ensure all ARIA ID values are unique to prevent elements from being overlooked by assistive technologies, like a screen reader.

Names and labels

Buttons have an accessible name
Buttons become unusable as they are announced simply as "button" when the button does not have an accessible name, when used by screen readers and other assistive technologies.
Document has a `<title>` element
Search engines, screen reader users and other assistive technology users rely on the title to provide an overview of the page and to help determine if the page is relevant to their search.
No form fields have multiple labels
Having multiple labels for form fields can be confusing to assistive technologies, like a screen reader.
`<frame>` or `<iframe>` elements have a title
Screen reader users and other assistive technology users rely on frame titles to describe the contents of frames.
Image elements have `[alt]` attributes
Provide short and descriptive alternative text where possible on informative elements.
`<input type="image">` elements have `[alt]` text
Input buttons with alternative text assist screen readers and other assistive technology users to understand its purpose.
Form elements have associated labels
Screen readers and other assistive technologies rely on labels to properly announce form controls.
Links have a discernible name
In order to improve the navigation for screen reader and other assistive technology users, use link text that is unique, focusable and discernible.
`<object>` elements have `[alt]` text
It is advised that alt text is used on '<object>' elements in order to provide meaning to screen reader and other assistive technology users, as these technologies are unable to translate non-text content.

Tables and lists

`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.
Screen readers and other assistive technologies may produce poor and inaccurate output when definition lists are not properly marked up.
Definition list items are wrapped in `<dl>` elements
In order for screen readers and other assistive technologies to properly announce definition list items ('<dt>' and '<dd>'), they must be wrapped in parent a '<dl>' element.
Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
Use proper list structure to aid screen readers and other assistive technologies.
List items (`<li>`) are contained within `<ul>` or `<ol>` parent elements
In order for screen readers to announce list items, ensure that list items ('<li>') are contained within parent '<ul>' or '<ol>' tags.
Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.
Screen readers and other assistive technologies have features to make navigating tables easier. Ensure that '<td>' cells using the headers attribute only refer to other cells in the same table, to improve screen reader user experience.
`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.
Screen readers and other assistive technologies have features to make navigating tables easier. Ensure that table headers refer to some set of cells, to improve screen reader user experience.

Internationalization and localization

`<html>` element has a `[lang]` attribute
It is advised to provide a lang attribute so that screen readers and other assistive technologies are guaranteed to announce the page's text correctly. When not provided, the user's default language setting will be used which may cause inaccuracies.
`<html>` element has a valid value for its `[lang]` attribute
Specify a valid BCP 47 language in order to help screen readers and other assistive technologies announce text properly.
`[lang]` attributes have a valid value
Specify a valid BCP 47 language on elements in order to help screen readers and other assistive technologies announce text properly.

Best practices

The document does not use `<meta http-equiv="refresh">`
Pages that refresh automatically cause a poor user experience as focus is directed back to the top of the page unexpectedly.
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
For users with low vision who rely on screen magnification, ensure that zooming is not disabled.

Audio and video

`<video>` elements contain a `<track>` element with `[kind="captions"]`
Codesandbox.io may provide assistance to deaf or hearing-impaired users with captions on videos.

Contrast

Background and foreground colors do not have a sufficient contrast ratio.
Many (if not most) users find low-contrast text difficult or impossible to read.
Failing Elements
Privacy Policy

Navigation

Heading elements are not in a sequentially-descending order
Properly order all headers and do not skip heading levels to better the navigation and readability for users of assistive technologies, like a screen reader.
Failing Elements
Product

Manual Checks

The page has a logical tab order
The visual layout should be logical in its tab order and users cannot focus elements that are offscreen.
Interactive controls are keyboard focusable
Ensure that custom interactive controls are keyboard focusable and that a focus indicator is displayed.
Interactive elements indicate their purpose and state
Ensure that interactive elements (such as links and buttons) are distinguishable from non-interactive elements and that they indicate their state.
The user's focus is directed to new content added to the page
When new content (such as a dialogue) is added to the page, the user's focus should be directed to it.
User focus is not accidentally trapped in a region
Avoid focus being accidentally trapped when a user tabs in and out of controls or regions on page.
Custom controls have associated labels
Ensure that custom interactive controls have associated labels, which are provided by aria-label and aria-labelledby attributes.
Custom controls have ARIA roles
Ensure that all custom interactive controls have appropriate ARIA roles.
Visual order on the page follows DOM order
Ensure that the DOM order matches with the page's visual order, in order to improve navigation for screen readers and other assistive technologies.
Offscreen content is hidden from assistive technology
Ensure that offscreen content is hidden through the use of "display:none" styling or the aria-hidden attribute.
HTML5 landmark elements are used to improve navigation
Elements such as <main> and <nav> are recommended as they are used by screen readers and other assistive technologies to improve keyboard navigation.
80

Best Practices

Indicates the recommended, best practices currently in place on the page and highlights the best practices that codesandbox.io should incorporate. This includes practices such as protecting pages with HTTPS.

Audits

Links to cross-origin destinations are safe
Improve performance and prevent security vulnerabilities by adding rel="noopener" and rel="noreferrer" to external links.
Avoids requesting the geolocation permission on page load
When requesting a user's location, provide context or consider tying the request to a user action to avoid confusion and mistrust from users.
Avoids requesting the notification permission on page load
When requesting permission to send notifications, provide context or consider tying the request to a user action to avoid confusion and mistrust from users.
Avoids front-end JavaScript libraries with known security vulnerabilities
Ensure that the use of third-party scripts is minimal and that only trusted third-party scripts are used as some may contain known security vulnerabilities which may be exploited by attackers.
Ensure CSP is effective against XSS attacks
Significantly reduce the risk of cross-site scripting attacks (XSS) by ensuring you have a strong Content Security Policy (CSP).
Description Directive Severity
No CSP found in enforcement mode
High

Audits

Allows users to paste into password fields
Ensure that password inputs may be pasted into to aid in the user's ability to use password managers and improve security.
Serves images with appropriate resolution
For maximum image clarity, ensure images have natural dimensions and are proportional to the display size and pixel ratio.
Fonts with `font-display: optional` are preloaded
It is recommended that optional fonts are preloaded.

Audits

Page has the HTML doctype
Ensure a doctype is specified to prevent the browser from switching to quirks-mode.
Properly defines charset
It is advised to declare a character encoding, optionally via a <meta> tag in the first 1024 bytes of the HTML or in the Content-Type HTTP response header.

Audits

Avoids `unload` event listeners
The 'unload' event does not fire reliably, causing issues with browser optimizations such as the Back-Forward Cache. It is recommended that 'pagehide' or 'visibilitychange' events are used instead.
Avoids Application Cache
Application cache is deprecated and is no longer recommended.
Detected JavaScript libraries
Below is a list of all front-end JavaScript libraries that were detected on the page.
Name Version
React
Gatsby
core-js
core-js-global@2.6.10
Avoids deprecated APIs
Avoid deprecated APIs which will eventually be removed the browser.
Page has valid source maps
Consider deploying source maps for added benefits such as the ability to debug while in production.
URL Map URL
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/dist/cdn/docsearch.min.js.map
https://codesandbox.io/webpack-runtime-38d2f4b1c7d7cb16b5cc.js
https://codesandbox.io/webpack-runtime-38d2f4b1c7d7cb16b5cc.js.map
https://codesandbox.io/styles-54c093d357ad2dd09420.js
https://codesandbox.io/styles-54c093d357ad2dd09420.js.map
https://codesandbox.io/component---src-pages-index-js-295d7b6c6efe012f5beb.js
https://codesandbox.io/component---src-pages-index-js-295d7b6c6efe012f5beb.js.map
https://codesandbox.io/app-708194e4ac8d35256b83.js
https://codesandbox.io/app-708194e4ac8d35256b83.js.map
https://codesandbox.io/43-488c3dabd69392009809.js
https://codesandbox.io/43-488c3dabd69392009809.js.map
https://codesandbox.io/2-bd90970fe6bfc2665e83.js
https://codesandbox.io/2-bd90970fe6bfc2665e83.js.map
https://codesandbox.io/1-29920b0332c01230873e.js
https://codesandbox.io/1-29920b0332c01230873e.js.map
No issues in the `Issues` panel in Chrome Devtools
There may be unresolved issues logged to Chrome Devtools.

Audits

Does not use HTTPS — 1 insecure request found
Ensure that all pages are protected with HTTPS (including those that do not handle sensitive data) as HTTPS prevents tampering and passive listening on communications between the app and its users. Additionally, HTTPS is a prerequisite for HTTP/2 and many new web platform APIs.
Insecure URL Request Resolution
http://codesandbox.io/
Allowed

Audits

Displays images with incorrect aspect ratio
Ensure that image display dimensions match their natural aspect ratio.
URL Aspect Ratio (Displayed) Aspect Ratio (Actual)
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/7-c37e0c5e9adae98b18b750c28fd2e1ed.png
324 x 570 (0.57)
356 x 579 (0.61)

Audits

Browser errors were logged to the console
Below is a list of all errors logged to the console, which indicate unresolved problems on the site.
Source Description
SHOW DETAILS
Failed to load resource: net::ERR_CONNECTION_FAILED
100

SEO

Indicates how well the page is optimized for ranking in search engines and highlights Search Engine Optimization (SEO) opportunities for codesandbox.io. This includes optimizations such as providing meta data.

Mobile Friendly

Has a `<meta name="viewport">` tag with `width` or `initial-scale`
It is advised to use a '<meta name="viewport">' tag for the optimization of codesandbox.io on mobile screens.
Document uses legible font sizes
Font sizes of 12px or less are too small to most mobile users without user gestures and further action. Aim for more than 60% of page text to use font sizes greater than 12px.
Tap targets are sized appropriately
Interactive elements (such as buttons and links) should be appropriately spaced, sized and easy enough to select or tap with regard to their surrounding elements.

Content Best Practices

Document has a `<title>` element
Search engines, screen reader users and other assistive technology users rely on the title to provide an overview of the page and to help determine if the page is relevant to their search.
Document has a meta description
Meta descriptions may be used by search engines when displaying a link to the page and should concisely summarize the page's content.
Links have descriptive text
Make use of descriptive link text to assist search engines in understanding the content.
Image elements have `[alt]` attributes
Provide short and descriptive alternative text where possible on informative elements.
Document has a valid `hreflang`
Search engines can be instructed to list specific versions of a page for a given language or region through the use of hreflang links.
Document has a valid `rel=canonical`
Search engines can be suggested which URL should be shown in search results through the use of canonical links.
Document avoids plugins
The content of plugins cannot be indexed by search engines and many devices either restrict or do not support them.

Crawling and Indexing

Page has successful HTTP status code
Avoid pages with unsuccessful HTTP status codes as they may not be indexed by search engines.
Links are crawlable
Ensure that the 'href' attribute of anchor elements links to the appropriate destination. This allows for more pages of the site to be discovered by search engines.
Page isn’t blocked from indexing
Pages that cannot be crawled by search engines cannot be indexed or included in their search results. Ensure that search engines have permission to crawl all pages that should be indexed.
robots.txt is valid
Malformed robots.txt files prevent crawlers from understanding how a site wants to be crawled or indexed, which can be devastating to SEO.

Manual Checks

Structured data is valid
Structured data can be validated through the use of the Structured Data Testing Tool and the Structured Data Linter.
36

Progressive Web App

Indicates how valid the aspects of a Progressive Web App (PWA) are for the page and highlights opportunities to enable/improve the PWA of codesandbox.io. This includes details about web app manifests.

PWA Optimized

Redirects HTTP traffic to HTTPS
It is advised to redirect all HTTP traffic to HTTPS, in order to enable secure web features for all users.
Content is sized correctly for the viewport
Ensure that the width of the app's content matches the width of the viewport, otherwise the app might not be optimized for mobile screens.
Has a `<meta name="viewport">` tag with `width` or `initial-scale`
It is advised to use a '<meta name="viewport">' tag for the optimization of codesandbox.io on mobile screens.

Installable

Web app manifest or service worker do not meet the installability requirements — 1 reason
User engagement may be increased by leveraging the browsers ability to proactively prompt users to add the app to their homescreen.
Failure reason
No manifest was fetched

PWA Optimized

Does not register a service worker that controls page and `start_url`
A service worker is used to provide Progressive Web Apps the use of features such as working offline, the ability for the app to be added to the homescreen as well as push notifications.
Is not configured for a custom splash screen
Themed splash screens ensure a high-quality user experience at launch for app users.
View Data
Does not set a theme color for the address bar.
A theme may be applied to the browser address bar, which ideally can be made to match the site.
View Data
Does not provide a valid `apple-touch-icon`
iOS users of Progressive Web Apps will benefit from an apple touch icon, which can be defined with 'apple-touch-icon', which must point to a non-transparent 192px (or 180px) square PNG.
Manifest doesn't have a maskable icon
Maskable icons are great to ensure that images fill the entire shape when installing the app on a device.

Manual Checks

Site works cross-browser
Ensure that the Progressive Web App works correctly across every major browser.
Page transitions don't feel like they block on the network
Users perceive apps with responsive, snappy transitions as higher peforming and ensures a great user experience, even on a slow network.
Each page has a URL
Ensure that all pages are deep linkable via URL. They should also be unique for the purpose of shareability on social media.
Avg. (All Categories) 72
Performance 47
Accessibility 97
Best Practices 80
SEO 96
Progressive Web App 42
0–49 (Fail) 50–89 (Average) 90–100 (Pass)
URL: https://codesandbox.io/
Updated: 8th June, 2021

1.68 seconds
First Contentful Paint (FCP)
79%
13%
8%

0.01 seconds
First Input Delay (FID)
97%
2%
1%

Simulate loading on mobile
47

Performance

Indicates how well the page is performing and highlights opportunities where performance may be improved for codesandbox.io. This includes details about optimizing page load times which can result in a better user experience.

Metrics

Speed Index — 3.3 s
The time taken for the page contents to be visibly populated.
Cumulative Layout Shift — 0
Cumulative Layout Shift is the measurement of visible elements collective movement within the viewport.
View Data

Opportunities

Defer offscreen images
Time to Interactive can be slowed down by resources on the page. Codesandbox.io should consider lazy-loading offscreen and hidden images.
Minify CSS
Cascading Style Sheets (CSS) files can contribute to network payload sizes. Codesandbox.io should consider minifying CSS files.
Minify JavaScript
JavaScript (JS) files can contribute to network payload sizes and increase script parse times. Codesandbox.io should consider minifying JS files.
Reduce unused CSS
Dead and/or unused rules in Style Sheets (CSS) can contribute to network payload sizes. Codesandbox.io should consider removing dead rules from style sheets and deferring the loading of CSS not used for above-the-fold content.
Efficiently encode images
Unoptimized images can consume more cellular data than what is necessary.
Enable text compression
Text-based resources should be served with compression, such as gzip, deflate or brotli.
Preconnect to required origins
Resource hints, such as 'preconnect' or 'dns-prefetch', may assist in establishing early connections to important third-party origins.
Initial server response time was short — Root document took 210 ms
It is advised to keep the server response time short for the main document, because all other requests depend on it.
URL Time Spent (Ms)
https://codesandbox.io/
207.231
Avoid multiple page redirects — Potential savings of 630 ms
Redirects can cause additional delays before the page can begin loading. Codesandbox.io should avoid multiple or unnecessary page redirects.
URL Time Spent (Ms)
http://codesandbox.io/
630
https://codesandbox.io/
0
Preload key requests
Key requests can be preloaded by using '<link rel=preload>'. Codesandbox.io should consider using '<link rel=preload>' to prioritize fetching resources that are currently requested later in page load.
Use video formats for animated content
Large GIFs are inefficient for delivering animated content. It is recommended to use MPEG4/WebM videos for animations and PNG/WebP for static images instead of GIF.
Remove duplicate modules in JavaScript bundles
Ensure that no duplicate JavaScript modules from bundles exist to reduce bytes consumed by network activity.
Preload Largest Contentful Paint image
It is recommended to preload images used by LCP elements, to improve LCP time.

Diagnostics

Uses efficient cache policy on static assets — 4 resources found
Codesandbox.io can speed up repeat visits by increasing the cache lifetime, which is essentially how long before a cached copy expires.
URL Cache TTL (Ms) Transfer Size (Bytes)
https://www.google-analytics.com/analytics.js
7200000
20221
https://static.cloudflareinsights.com/beacon.min.js
86400000
5553
https://codesandbox.io/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js
172800000
1194
https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.css
604800000
6454
Avoids an excessive DOM size — 363 elements
A large DOM (Document Object Model) will increase memory usage, cause longer system calculations as well as costly layout reflows.
Statistic Element Value
Total DOM Elements
363
Maximum DOM Depth
path
14
Maximum Child Elements
body
16
Avoid chaining critical requests — 2 chains found
Below is a list of Critical Request Chains, which shows which resources are loaded with a high priority. Codesandbox.io should consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
User Timing marks and measures — 4 user timings
Make use of the User Timing API to measure an app's real-world performance during key user experiences.
Name Type Start Time (Ms) Duration (Ms)
Next.js-before-hydration
Measure
369.076
544.135
Next.js-hydration
Measure
913.211
18.855
beforeRender
Mark
913.25
afterHydrate
Mark
932.091
All text remains visible during webfont loads
Make use of the font-display CSS feature, which will ensure text is user-visible while webfonts are loading.
Keep request counts low and transfer sizes small — 71 requests • 6,523 KiB
It is advised to add a budgets.json file in order to set budgets for the quantity and size of page resources.
Resource Type Requests Transfer Size (Bytes)
Total
71
6679121
Image
21
6033983
Script
30
500538
Other
13
66173
Document
2
55139
Font
1
11662
Stylesheet
3
11626
Media
1
0
Third-party
36
285436
Minimize third-party usage — Third-party code blocked the main thread for 140 ms
It is advised to either limit, remove or delay the loading of redundant third-party code which may be significantly impacting load performance.
Third-Party Transfer Size (Bytes) Main-Thread Blocking Time (Ms)
SHOW DETAILS
57516
71.904
SHOW DETAILS
21267
56.224
SHOW DETAILS
45516
7.88
SHOW DETAILS
34991
0
SHOW DETAILS
13189
0
SHOW DETAILS
6454
0
SHOW DETAILS
691
0
SHOW DETAILS
678
0
Lazy load third-party resources with facades
Consider replacing third-party embeds with a facade until they are required (use lazy loading).
Largest Contentful Paint element — 1 element found
The element which was identified as the Largest Contentful Paint.
Element
Where teams build faster, together
Avoid large layout shifts
Below is a list of all DOM elements that contribute to the CLS of the page.
Uses passive listeners to improve scrolling performance
Improve the page's scroll performance by marking touch and wheel event listeners as 'passive'.
Avoids `document.write()`
Avoid or limit the use of external scripts that are dynamically injected via 'document.write()' as users on slow connections will be delayed by tens of seconds.
Avoid long main-thread tasks — 14 long tasks found
Below is a list of the longest tasks on the main thread, which is useful when identifying the worst input delay contributors.
URL Start Time (Ms) Duration (Ms)
https://codesandbox.io/app-708194e4ac8d35256b83.js
5310
243
https://codesandbox.io/app-708194e4ac8d35256b83.js
6696
198
https://codesandbox.io/app-708194e4ac8d35256b83.js
6894
188
https://playdotjs.com/_next/static/chunks/framework.767949b9f2588a43c494.js
4590
126
https://cdn.amplitude.com/libs/amplitude-7.1.0-min.gz.js
4792
114
https://www.google-analytics.com/gtm/js?id=GTM-TLB9J48&t=gtm4&cid=278086380.1623144322
5581
107
https://codesandbox.io/
1500
86
https://playdotjs.com/_next/static/chunks/framework.767949b9f2588a43c494.js
4440
86
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
3242.022649765
84
https://www.google-analytics.com/analytics.js
4716
76
https://codesandbox.io/
1638
71
https://www.googletagmanager.com/gtm.js?id=GTM-T3L6RFK
3532
68
https://codesandbox.io/
1586
52
https://www.googletagmanager.com/gtm.js?id=GTM-T3L6RFK
3480
52
Avoid non-composited animations
It is recommended to avoid non-composited animations which are often janky and increase CLS.

Budgets

Performance budget
It is advised to keep the quantity and size of all network requests under the targets set by the provided performance budget.
Timing budget
It is advised to set a timing budget to monitor the performance of your site.

Other

Network Requests
Below is a list of network requests that were made during page load.
URL Protocol Start Time (Ms) End Time (Ms) Transfer Size (Bytes) Resource Size (Bytes) Status Code MIME Type Resource Type
http://codesandbox.io/
http/1.1
0
49.985999939963
504
0
301
https://codesandbox.io/
h2
50.609999801964
256.84299995191
50927
149545
200
text/html
Document
https://codesandbox.io/component---src-pages-index-js-295d7b6c6efe012f5beb.js
h2
276.96199994534
308.6979999207
43941
113541
200
application/javascript
Script
https://codesandbox.io/app-708194e4ac8d35256b83.js
h2
277.32299990021
323.45799985342
110282
374955
200
application/javascript
Script
https://codesandbox.io/styles-54c093d357ad2dd09420.js
h2
277.70499978215
300.19199987873
830
248
200
application/javascript
Script
https://codesandbox.io/2-bd90970fe6bfc2665e83.js
h2
278.03699998185
306.27199984156
21488
89289
200
application/javascript
Script
https://codesandbox.io/43-488c3dabd69392009809.js
h2
278.27899996191
305.23599986918
16300
50335
200
application/javascript
Script
https://codesandbox.io/1-29920b0332c01230873e.js
h2
278.56000000611
311.40299979597
49704
157324
200
application/javascript
Script
https://codesandbox.io/webpack-runtime-38d2f4b1c7d7cb16b5cc.js
h2
279.2129998561
301.35499988683
3054
8209
200
application/javascript
Script
https://codesandbox.io/page-data/index/page-data.json
h2
279.44899979047
402.14799996465
744
179
200
application/json
Other
https://fonts.googleapis.com/css?family=Open+Sans:400|Roboto:400i,400&display=swap
h2
281.08699992299
300.89899990708
1527
7535
200
text/css
Stylesheet
https://www.googletagmanager.com/gtm.js?id=GTM-T3L6RFK
h2
288.75999990851
423.70899999514
45516
125601
200
application/javascript
Script
data
292.92899998836
293.05699979886
0
1589
200
image/svg+xml
Image
data
295.63699988648
295.81499984488
0
4469
200
image/svg+xml
Image
data
297.70399979316
297.85299999639
0
944
200
image/svg+xml
Image
data
299.51899987645
299.59799977951
0
347
200
image/svg+xml
Image
data
301.42799997702
301.49699980393
0
436
200
image/svg+xml
Image
https://codesandbox.io/static/video-e6a34ad1b9555966b2b8be018e27c2a2.png
h2
306.94799986668
345.7070000004
349978
349212
200
image/png
Image
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
h2
307.21199978143
385.77099982649
1882725
1881958
200
image/png
Image
https://codesandbox.io/static/phone-48c67ab1b26fae0f28d4cbcfe103ddb9.png
h2
307.44499992579
332.53299980424
83072
82311
200
image/png
Image
https://codesandbox.io/static/danilowoz-8dc7e702f75beb452da0a562b5233fe6.jpg
h2
307.64699983411
329.73299990408
13664
12899
200
image/jpeg
Image
https://codesandbox.io/static/sid-c01f392777ec43b1ef66c73fba86e223.jpg
h2
308.00499999896
361.214999808
56476
55712
200
image/jpeg
Image
https://codesandbox.io/static/christian-a152cf4260859450fad84281ca0e9ec1.png
h2
308.34899982437
344.95399985462
47996
47232
200
image/png
Image
https://codesandbox.io/static/tamas-e1b8d4ad4e52bd5b4190bf5df91661c9.png
h2
309.520999901
511.83599978685
77947
77185
200
image/png
Image
https://codesandbox.io/static/ives-7a1c194d7343d82baf75c9cd9d209513.png
h2
309.86799998209
335.15399997123
14424
13661
200
image/png
Image
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
h2
312.28799978271
337.91399979964
353767
353001
200
image/png
Image
https://codesandbox.io/static/brian-52358144e232bdf5f26b70c1c6bd9984.png
h2
312.52399994992
335.60599992052
27878
27114
200
image/png
Image
https://fonts.gstatic.com/s/roboto/v27/KFOmCnqEu92Fr1Mu4mxKKTU1Kg.woff2
h2
327.6079997886
330.59699996375
11662
11032
200
font/woff2
Font
https://playdotjs.com/
h2
369.77200000547
394.74599994719
4212
14912
200
text/html
Document
data
371.42099998891
371.49399984628
0
714
200
image/svg+xml
Image
data
373.0749997776
373.14899987541
0
434
200
image/svg+xml
Image
data
374.95799991302
375.08499994874
0
3966
200
image/svg+xml
Image
data
376.69599987566
376.79899996147
0
2375
200
image/svg+xml
Image
data
378.66099993698
378.79899982363
0
3569
200
image/svg+xml
Image
data
380.81000000238
380.97299984656
0
4993
200
image/svg+xml
Image
data
383.01799981855
383.15099989995
0
4589
200
image/svg+xml
Image
data
383.62199999392
383.76499991864
0
5065
200
image/png
Image
https://codesandbox.io/static/peggy-8e312e7d8020e9f724ba176af345e54d.png
h2
393.78899987787
420.47299980186
33494
32731
200
image/png
Image
https://codesandbox.io/static/jonnie-253e74f068f86b528dd8a7ad41a5650b.png
h2
396.23199985363
421.0379999131
16947
16183
200
image/png
Image
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
h2
396.36499993503
450.74099977501
211888
211122
200
image/png
Image
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
h2
396.50599984452
447.37700000405
1152329
1151561
200
image/png
Image
https://codesandbox.io/static/7-c37e0c5e9adae98b18b750c28fd2e1ed.png
h2
396.72399987467
421.88599985093
41333
40569
200
image/png
Image
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
h2
396.83099999093
541.41299985349
345191
344425
200
image/png
Image
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
h2
396.96799986996
426.85399996117
339934
339168
200
image/png
Image
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
h2
397.06799993291
509.31599992327
404062
403296
200
image/png
Image
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
h2
397.14999985881
434.62899979204
579598
578832
200
image/png
Image
https://codesandbox.io/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js
h2
397.27099984884
418.1329999119
1194
1239
200
application/javascript
Script
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
h2
397.33999990858
430.28599978425
34991
111704
200
application/javascript
Script
https://static.cloudflareinsights.com/beacon.min.js
h2
397.45199983008
422.96599992551
5553
13614
200
text/javascript
Script
https://codesandbox.io/static/video-fe2b0a3ea133c28d5a99cfc0ed2313ff.mp4
446.64499978535
1034.6949999221
0
0
-1
Media
data
452.27299979888
452.36599980853
0
1303
200
image/png
Image
data
452.54399999976
452.61599984951
0
950
200
image/png
Image
data
452.78099994175
452.82599981874
0
787
200
image/png
Image
https://playdotjs.com/_next/static/css/625bcde5887b4a5ea898.css
h2
526.41399996355
552.46899998747
3645
10464
200
text/css
Stylesheet
https://playdotjs.com/_next/static/chunks/15.c16d2cb92e0fcc0b8e55.js
h2
527.01999992132
550.8339998778
1087
1399
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/commons.80fd155a1972871b5a38.js
h2
533.06799987331
560.04899996333
12749
34736
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/13.bdf70fa0b0f4d5bb6c56.js
h2
533.36299979128
556.6819999367
2138
3226
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/16.ef3e948cebfbdf1396c7.js
h2
534.68599985354
554.80799986981
749
228
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/17.9d2818794b33463320e3.js
h2
534.88799999468
647.64299988747
1387
866
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/18.a5f3f4b732a5f627315e.js
h2
536.39999986626
557.21299978904
1419
898
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/14.f2235007b7bf874c3a6c.js
h2
536.61699988879
557.48999980278
2147
3492
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/5.7257b3b22b17bd752e53.js
h2
536.85399983078
556.31199991331
2393
4071
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/main-e4383e021aef726550db.js
h2
537.18999982812
582.91299990378
8085
20997
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/webpack-32462ae3750b38e7d006.js
h2
537.49399981461
559.48499985971
1921
2567
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/framework.767949b9f2588a43c494.js
h2
537.87999995984
572.44599983096
44373
130886
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/pages/_app-47adf0ed776ded938e2b.js
h2
538.07699983008
562.77899979614
1288
1721
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/f63252b21a915a295187fea80c9b107d3f313aa8.99e70789e9424fc300d1.js
h2
538.25999982655
562.41499981843
4699
12154
200
application/javascript
Script
https://playdotjs.com/_next/static/chunks/pages/index-2d156e83fa2351f35751.js
h2
538.38999988511
563.43199987896
4892
11916
200
application/javascript
Script
https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.css
h2
610.94699986279
638.28299986199
6454
18975
200
text/css
Stylesheet
https://playdotjs.com/_next/static/jVatzZ61oHEfRoSGsdwc5/_buildManifest.js
h2
637.04599998891
657.92599995621
1147
635
200
application/javascript
Script
https://playdotjs.com/_next/static/jVatzZ61oHEfRoSGsdwc5/_ssgManifest.js
h2
637.19799998216
656.34999983013
584
76
200
application/javascript
Script
https://www.google-analytics.com/analytics.js
h2
716.49699984118
720.98199999891
20221
49153
200
text/javascript
Script
https://cdn.amplitude.com/libs/amplitude-7.1.0-min.gz.js
http/1.1
720.57999996468
4243.7809999101
20331
61487
200
application/javascript
Script
https://5o7brbeivd-dsn.algolia.net/1/indexes/prod_sandboxes/query?x-algolia-agent=Algolia%20for%20JavaScript%20(3.33.0)%3B%20Browser%20(lite)&x-algolia-application-id=5O7BRBEIVD&x-algolia-api-key=85194a1433e4196466a0f80135439c79
http/1.1
801.37899983674
1574.7839999385
666
226
200
application/json
XHR
data
843.63599983044
843.69899984449
0
271
200
image/svg+xml
Image
https://codesandbox.io/page-data/legal/privacy/page-data.json
h2
895.32699994743
1024.6319998987
13132
0
200
application/json
Other
https://www.google-analytics.com/gtm/js?id=GTM-TLB9J48&t=gtm4&cid=278086380.1623144322
h2
962.4129999429
982.43599990383
36075
90054
200
application/javascript
Script
https://www.google-analytics.com/j/collect?v=1&_v=j90&aip=1&a=697629212&t=pageview&_s=1&dl=https%3A%2F%2Fcodesandbox.io%2F&ul=en-us&de=UTF-8&dt=CodeSandbox%3A%20Online%20Code%20Editor%20and%20IDE%20for%20Rapid%20Web%20Development&sd=24-bit&sr=360x640&vp=360x640&je=0&_u=aGDAAEADQAAAAC~&jid=454289976&gjid=1860179175&cid=278086380.1623144322&tid=UA-89432508-1&_gid=925879459.1623144322&_r=1&gtm=2wg621T3L6RFK&z=1169473926
h2
1017.522999784
1021.022999892
618
2
200
text/plain
XHR
https://www.google-analytics.com/collect?v=1&_v=j90&a=697629212&t=event&ni=0&_s=1&dl=https%3A%2F%2Fcodesandbox.io%2F&ul=en-us&de=UTF-8&dt=CodeSandbox%3A%20Online%20Code%20Editor%20and%20IDE%20for%20Rapid%20Web%20Development&sd=24-bit&sr=360x640&vp=360x640&je=0&ec=Page%20Interaction&ea=test&el=homepage&_u=aGDAAEADQAAAAC~&jid=&gjid=&cid=278086380.1623144322&tid=UA-89432508-1&_gid=925879459.1623144322&gtm=2wg621T3L6RFK&z=175760809
h2
1026.8549998291
1030.6439998094
602
35
200
image/gif
Image
https://stats.g.doubleclick.net/j/collect?t=dc&aip=1&_r=3&v=1&_v=j90&tid=UA-89432508-1&cid=278086380.1623144322&jid=454289976&gjid=1860179175&_gid=925879459.1623144322&_u=aGDAAEACQAAAAC~&z=218236402
h2
1032.6129999012
1036.9070000015
691
2
200
text/plain
XHR
https://codesandbox.io/page-data/legal/privacy/page-data.json
h2
1041.9809999876
1216.9179997873
13314
56507
200
application/json
XHR
https://www.google.com/ads/ga-audiences?t=sr&aip=1&_r=4&slf_rd=1&v=1&_v=j90&tid=UA-89432508-1&cid=278086380.1623144322&jid=454289976&_u=aGDAAEACQAAAAC~&z=1305872732
h2
1043.940999778
1051.3349999674
678
42
200
image/gif
Image
https://codesandbox.io/component---src-pages-legal-privacy-js-d12ec273cfaffbab0ac0.js
h2
1220.6759999972
1413.4189998731
35159
0
200
application/javascript
Other
https://api2.amplitude.com/
h2
4287.2709999792
4635.3419998195
234
7
200
text/html
XHR
https://codesandbox.io/cdn-cgi/rum?req_id=65c11285dc5505d2
h2
4291.137999855
4322.9559999891
409
0
200
text/plain
XHR
https://api2.amplitude.com/
h2
4808.8429998606
5153.715999797
234
7
200
text/html
XHR
https://api2.amplitude.com/
h2
5158.2159998361
5255.1229998935
234
7
200
text/html
XHR
https://api2.amplitude.com/
h2
5600.3969998565
5692.6869999152
234
7
200
text/html
XHR
Network Round Trip Times — 0 ms
High Network RTT (Round Trip Times) can have a large impact on performance. Providing servers geographically closer to the user could improve performance.
Server Backend Latencies — 0 ms
High server latencies indicate the server is overloaded or has a poor backend performance.
Tasks
Below is a list of the top-level main thread tasks that executed during page load.
Start Time (Ms) End Time (Ms)
271.872
11.467
284.221
5.248
289.744
22.196
312.608
5.667
323.544
43.232
368.465
25.925
409.49
35.551
445.127
11.562
465.006
7.647
480.24
17.945
508.118
21.022
534.847
11.786
548.772
5.536
560.455
60.692
626.387
13.121
655.451
49.407
706.133
10.441
716.589
16.973
740.79
5.302
747.649
93.953
841.626
17.813
876.065
21.395
913.833
31.464
952.887
19.061
971.962
6.949
1001.716
6.949
1009.348
26.805
1063.851
5.863
4257.652
28.463
4288.003
7.515
4295.538
5.07
4307.153
6.144
4813.479
5.96
Diagnostics
Below is a collection of useful page vitals.
View Data
Metrics
Below is a collection of metrics.
View Data
Script Treemap Data
Provide as required, for treemap app.

Metrics

First Contentful Paint — 3.0 s
The time taken for the first image or text on the page to be rendered.
Time to Interactive — 7.0 s
The time taken for the page to become fully interactive.

Other

Max Potential First Input Delay — 240 ms
Users could experience a delay when interacting with the page.
First Meaningful Paint — 3.0 s
The time taken for the primary content of the page to be rendered.

Opportunities

Reduce unused JavaScript — Potential savings of 109 KiB
It is advised to remove unused JavaScript in order to reduce bytes consumed by network activity.
URL Transfer Size (Bytes) Potential Savings (Bytes)
https://codesandbox.io/app-708194e4ac8d35256b83.js
110282
59260
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
34991
27636
https://www.google-analytics.com/gtm/js?id=GTM-TLB9J48&t=gtm4&cid=278086380.1623144322
36075
24878
Avoid serving legacy JavaScript to modern browsers — Potential savings of 34 KiB
Polyfills and transforms enable legacy browsers to use new JavaScript features. For bundled JavaScript it is recommended to adopt a modern script deployment strategy using module/nomodule feature detection. This will reduce the amount of code shipped to modern browsers.
URL Potential Savings (Bytes)
https://codesandbox.io/1-29920b0332c01230873e.js
10648
https://codesandbox.io/app-708194e4ac8d35256b83.js
10638
https://codesandbox.io/43-488c3dabd69392009809.js
6613
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
6449
https://playdotjs.com/_next/static/chunks/commons.80fd155a1972871b5a38.js
61
https://cdn.amplitude.com/libs/amplitude-7.1.0-min.gz.js
55

Diagnostics

Reduce JavaScript execution time — 2.1 s
JavaScript (JS) execution time can be lowered by reducing the time required for parsing, compiling and executing JS. Delivering smaller JS payloads may help with this.
URL Total CPU Time (Ms) Script Evaluation (Ms) Script Parse (Ms)
https://codesandbox.io/
1175.092
109.244
8.704
https://codesandbox.io/1-29920b0332c01230873e.js
966.056
243.596
14.492
https://codesandbox.io/app-708194e4ac8d35256b83.js
940.688
835.748
31.104
Unattributable
581.864
10.88
0.64
https://playdotjs.com/_next/static/chunks/framework.767949b9f2588a43c494.js
231.476
215.924
9.652
https://cdn.amplitude.com/libs/amplitude-7.1.0-min.gz.js
174.6
151.436
5
https://www.googletagmanager.com/gtm.js?id=GTM-T3L6RFK
145.42
124.472
14.976
https://www.google-analytics.com/gtm/js?id=GTM-TLB9J48&t=gtm4&cid=278086380.1623144322
142.296
126.94
10.516
https://www.google-analytics.com/analytics.js
112.072
80.592
22.572
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
66.728
47.808
9.772

Metrics

Largest Contentful Paint — 22.1 s
The timing of the largest text or image that is painted.
Total Blocking Time — 720 ms
The total blocking time is the sum of all time periods between First Contentful Paint and Time to Interactive (when task length exceeded 50ms).

Opportunities

Eliminate render-blocking resources — Potential savings of 810 ms
Resources, such as JavaScript and style sheets, can block the first paint of the page. Codesandbox.io should consider delivering critical JavaScript/style sheets (JS/CSS) inline and deferring all non-critical JS/CSS.
URL Transfer Size (Bytes) Potential Savings (Ms)
https://fonts.googleapis.com/css?family=Open+Sans:400|Roboto:400i,400&display=swap
1527
780
Properly size images — Potential savings of 2,109 KiB
Images can slow down the page's load time. Codesandbox.io should consider serving more appropriate-sized images.
URL Resource Size (Bytes) Potential Savings (Bytes)
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
1881958
1857694
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
353001
302184
Serve images in next-gen formats — Potential savings of 4,144 KiB
Consider JPEG 2000, JPEG XR or WebP image formats which provide better compression than PNG and JPEG.
URL Resource Size (Bytes) Potential Savings (Bytes)
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
1881958
1225618
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
1151561
832393
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
578832
459502
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
353001
296541
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
403296
287500
https://codesandbox.io/static/video-e6a34ad1b9555966b2b8be018e27c2a2.png
349212
267134
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
344425
258543
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
339168
237126
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
211122
124788
https://codesandbox.io/static/phone-48c67ab1b26fae0f28d4cbcfe103ddb9.png
82311
59215
https://codesandbox.io/static/tamas-e1b8d4ad4e52bd5b4190bf5df91661c9.png
77185
57159
https://codesandbox.io/static/christian-a152cf4260859450fad84281ca0e9ec1.png
47232
42114
https://codesandbox.io/static/peggy-8e312e7d8020e9f724ba176af345e54d.png
32731
27795
https://codesandbox.io/static/brian-52358144e232bdf5f26b70c1c6bd9984.png
27114
22492
https://codesandbox.io/static/7-c37e0c5e9adae98b18b750c28fd2e1ed.png
40569
15837
https://codesandbox.io/static/jonnie-253e74f068f86b528dd8a7ad41a5650b.png
16183
11833
https://codesandbox.io/static/sid-c01f392777ec43b1ef66c73fba86e223.jpg
55712
9440
https://codesandbox.io/static/ives-7a1c194d7343d82baf75c9cd9d209513.png
13661
8289

Diagnostics

Avoid enormous network payloads — Total size was 6,523 KiB
Large network payloads can cost users money and are linked to long load times.
URL Transfer Size (Bytes)
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
1882725
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
1152329
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
579598
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
404062
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
353767
https://codesandbox.io/static/video-e6a34ad1b9555966b2b8be018e27c2a2.png
349978
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
345191
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
339934
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
211888
https://codesandbox.io/app-708194e4ac8d35256b83.js
110282
Minimize main-thread work — 4.8 s
Main-thread work timing can be lowered by reducing the time required for parsing, compiling and executing JS. Delivering smaller JS payloads may help with this.
Category Time Spent (Ms)
Script Evaluation
2013.756
Other
1035.576
Style & Layout
839.916
Rendering
547.348
Script Parsing & Compilation
193.924
Parse HTML & CSS
107.592
Garbage Collection
21.332
Image elements do not have explicit `width` and `height`
Reduce layout shifts and improve CLS by setting explicit width and height properties on image elements.
URL Failing Elements
https://codesandbox.io/static/pad-afb434520cc7d5360fe7afee3dc6cd78.png
Play.js
https://codesandbox.io/static/dashboard-b795218268f48a7c4fbb9c92799e7905.png
img

Other

First Contentful Paint (3G) — 6360 ms
The time taken for the first image or text on the page to be rendered while on a 3G network.
97

Accessibility

Indicates how accessible the page is and highlights opportunities where the page can be made more accessible to users of codesandbox.io. This includes details about various page attributes that can be optimized.

Navigation

`[accesskey]` values are unique
Access keys assist users with focusing on different parts of the page. Each access key should be unique for proper navigation.
The page contains a heading, skip link, or landmark region
It is advised to provide ways to bypass repetitive content, allowing users to navigate the page efficiently.
`[id]` attributes on active, focusable elements are unique
Ensure all focusable elements have a unique id value to allow them to be visible to users of assistive technologies, like a screen reader.
No element has a `[tabindex]` value greater than 0
Although technically valid, a tabindex value greater than 0 often creates frustrating experiences for users who rely on assistive technologies.

ARIA

`[aria-*]` attributes match their roles
Avoid mismatching 'aria-*' attributes and their 'role' value, as it invalidates the attribute.
`button`, `link`, and `menuitem` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[aria-hidden="true"]` is not present on the document `<body>`
If aria-hidden=true is set on the document body, assistive technologies, like a screen reader will work inconsistently.
`[aria-hidden="true"]` elements do not contain focusable descendents
Interactive elements within an aria-hidden=true element are unavailable to users of assistive technologies, like a screen reader.
ARIA input fields have accessible names
Generic names are announced to users of assistive technologies, like a screen reader, when an input field does not have an accessible name specified.
ARIA `meter` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
ARIA `progressbar` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[role]`s have all required `[aria-*]` attributes
Some ARIA roles have required 'aria-*' attributes, which provide essential information about state and functionality.
Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
Some ARIA parent roles cannot perform their intended functions if specific child roles are not used.
`[role]`s are contained by their required parent element
Some ARIA child roles cannot perform their intended functions if specific parent roles are not used.
`[role]` values are valid
All ARIA roles require valid values to perform their intended functions.
ARIA toggle fields have accessible names
Generic names are announced to users of assistive technologies, like a screen reader, when a toggle field does not have an accessible name specified.
ARIA `tooltip` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
ARIA `treeitem` elements have accessible names
Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[aria-*]` attributes have valid values
ARIA attributes cannot be interpreted with invalid values when used by screen readers and other assistive technologies.
`[aria-*]` attributes are valid and not misspelled
ARIA attributes cannot be interpreted with invalid names when used by screen readers and other assistive technologies.
ARIA IDs are unique
Ensure all ARIA ID values are unique to prevent elements from being overlooked by assistive technologies, like a screen reader.

Names and labels

Buttons have an accessible name
Buttons become unusable as they are announced simply as "button" when the button does not have an accessible name, when used by screen readers and other assistive technologies.
Document has a `<title>` element
Search engines, screen reader users and other assistive technology users rely on the title to provide an overview of the page and to help determine if the page is relevant to their search.
No form fields have multiple labels
Having multiple labels for form fields can be confusing to assistive technologies, like a screen reader.
`<frame>` or `<iframe>` elements have a title
Screen reader users and other assistive technology users rely on frame titles to describe the contents of frames.
Image elements have `[alt]` attributes
Provide short and descriptive alternative text where possible on informative elements.
`<input type="image">` elements have `[alt]` text
Input buttons with alternative text assist screen readers and other assistive technology users to understand its purpose.
Form elements have associated labels
Screen readers and other assistive technologies rely on labels to properly announce form controls.
Links have a discernible name
In order to improve the navigation for screen reader and other assistive technology users, use link text that is unique, focusable and discernible.
`<object>` elements have `[alt]` text
It is advised that alt text is used on '<object>' elements in order to provide meaning to screen reader and other assistive technology users, as these technologies are unable to translate non-text content.

Tables and lists

`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.
Screen readers and other assistive technologies may produce poor and inaccurate output when definition lists are not properly marked up.
Definition list items are wrapped in `<dl>` elements
In order for screen readers and other assistive technologies to properly announce definition list items ('<dt>' and '<dd>'), they must be wrapped in parent a '<dl>' element.
Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
Use proper list structure to aid screen readers and other assistive technologies.
List items (`<li>`) are contained within `<ul>` or `<ol>` parent elements
In order for screen readers to announce list items, ensure that list items ('<li>') are contained within parent '<ul>' or '<ol>' tags.
Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.
Screen readers and other assistive technologies have features to make navigating tables easier. Ensure that '<td>' cells using the headers attribute only refer to other cells in the same table, to improve screen reader user experience.
`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.
Screen readers and other assistive technologies have features to make navigating tables easier. Ensure that table headers refer to some set of cells, to improve screen reader user experience.

Internationalization and localization

`<html>` element has a `[lang]` attribute
It is advised to provide a lang attribute so that screen readers and other assistive technologies are guaranteed to announce the page's text correctly. When not provided, the user's default language setting will be used which may cause inaccuracies.
`<html>` element has a valid value for its `[lang]` attribute
Specify a valid BCP 47 language in order to help screen readers and other assistive technologies announce text properly.
`[lang]` attributes have a valid value
Specify a valid BCP 47 language on elements in order to help screen readers and other assistive technologies announce text properly.

Best practices

The document does not use `<meta http-equiv="refresh">`
Pages that refresh automatically cause a poor user experience as focus is directed back to the top of the page unexpectedly.
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
For users with low vision who rely on screen magnification, ensure that zooming is not disabled.

Audio and video

`<video>` elements contain a `<track>` element with `[kind="captions"]`
Codesandbox.io may provide assistance to deaf or hearing-impaired users with captions on videos.

Contrast

Background and foreground colors do not have a sufficient contrast ratio.
Many (if not most) users find low-contrast text difficult or impossible to read.
Failing Elements
Privacy Policy

Navigation

Heading elements are not in a sequentially-descending order
Properly order all headers and do not skip heading levels to better the navigation and readability for users of assistive technologies, like a screen reader.
Failing Elements
Product

Manual Checks

The page has a logical tab order
The visual layout should be logical in its tab order and users cannot focus elements that are offscreen.
Interactive controls are keyboard focusable
Ensure that custom interactive controls are keyboard focusable and that a focus indicator is displayed.
Interactive elements indicate their purpose and state
Ensure that interactive elements (such as links and buttons) are distinguishable from non-interactive elements and that they indicate their state.
The user's focus is directed to new content added to the page
When new content (such as a dialogue) is added to the page, the user's focus should be directed to it.
User focus is not accidentally trapped in a region
Avoid focus being accidentally trapped when a user tabs in and out of controls or regions on page.
Custom controls have associated labels
Ensure that custom interactive controls have associated labels, which are provided by aria-label and aria-labelledby attributes.
Custom controls have ARIA roles
Ensure that all custom interactive controls have appropriate ARIA roles.
Visual order on the page follows DOM order
Ensure that the DOM order matches with the page's visual order, in order to improve navigation for screen readers and other assistive technologies.
Offscreen content is hidden from assistive technology
Ensure that offscreen content is hidden through the use of "display:none" styling or the aria-hidden attribute.
HTML5 landmark elements are used to improve navigation
Elements such as <main> and <nav> are recommended as they are used by screen readers and other assistive technologies to improve keyboard navigation.
80

Best Practices

Indicates the recommended, best practices currently in place on the page and highlights the best practices that codesandbox.io should incorporate. This includes practices such as protecting pages with HTTPS.

Audits

Links to cross-origin destinations are safe
Improve performance and prevent security vulnerabilities by adding rel="noopener" and rel="noreferrer" to external links.
Avoids requesting the geolocation permission on page load
When requesting a user's location, provide context or consider tying the request to a user action to avoid confusion and mistrust from users.
Avoids requesting the notification permission on page load
When requesting permission to send notifications, provide context or consider tying the request to a user action to avoid confusion and mistrust from users.
Avoids front-end JavaScript libraries with known security vulnerabilities
Ensure that the use of third-party scripts is minimal and that only trusted third-party scripts are used as some may contain known security vulnerabilities which may be exploited by attackers.
Ensure CSP is effective against XSS attacks
Significantly reduce the risk of cross-site scripting attacks (XSS) by ensuring you have a strong Content Security Policy (CSP).
Description Directive Severity
No CSP found in enforcement mode
High

Audits

Allows users to paste into password fields
Ensure that password inputs may be pasted into to aid in the user's ability to use password managers and improve security.
Serves images with appropriate resolution
For maximum image clarity, ensure images have natural dimensions and are proportional to the display size and pixel ratio.
Fonts with `font-display: optional` are preloaded
It is recommended that optional fonts are preloaded.

Audits

Page has the HTML doctype
Ensure a doctype is specified to prevent the browser from switching to quirks-mode.
Properly defines charset
It is advised to declare a character encoding, optionally via a <meta> tag in the first 1024 bytes of the HTML or in the Content-Type HTTP response header.

Audits

Avoids `unload` event listeners
The 'unload' event does not fire reliably, causing issues with browser optimizations such as the Back-Forward Cache. It is recommended that 'pagehide' or 'visibilitychange' events are used instead.
Avoids Application Cache
Application cache is deprecated and is no longer recommended.
Detected JavaScript libraries
Below is a list of all front-end JavaScript libraries that were detected on the page.
Name Version
React
Gatsby
core-js
core-js-global@2.6.10
Avoids deprecated APIs
Avoid deprecated APIs which will eventually be removed the browser.
Page has valid source maps
Consider deploying source maps for added benefits such as the ability to debug while in production.
URL Map URL
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/docsearch.min.js
https://unpkg.com/docsearch.js@2.4.1/dist/cdn/dist/cdn/docsearch.min.js.map
https://codesandbox.io/webpack-runtime-38d2f4b1c7d7cb16b5cc.js
https://codesandbox.io/webpack-runtime-38d2f4b1c7d7cb16b5cc.js.map
https://codesandbox.io/styles-54c093d357ad2dd09420.js
https://codesandbox.io/styles-54c093d357ad2dd09420.js.map
https://codesandbox.io/component---src-pages-index-js-295d7b6c6efe012f5beb.js
https://codesandbox.io/component---src-pages-index-js-295d7b6c6efe012f5beb.js.map
https://codesandbox.io/app-708194e4ac8d35256b83.js
https://codesandbox.io/app-708194e4ac8d35256b83.js.map
https://codesandbox.io/43-488c3dabd69392009809.js
https://codesandbox.io/43-488c3dabd69392009809.js.map
https://codesandbox.io/2-bd90970fe6bfc2665e83.js
https://codesandbox.io/2-bd90970fe6bfc2665e83.js.map
https://codesandbox.io/1-29920b0332c01230873e.js
https://codesandbox.io/1-29920b0332c01230873e.js.map
No issues in the `Issues` panel in Chrome Devtools
There may be unresolved issues logged to Chrome Devtools.

Audits

Does not use HTTPS — 1 insecure request found
Ensure that all pages are protected with HTTPS (including those that do not handle sensitive data) as HTTPS prevents tampering and passive listening on communications between the app and its users. Additionally, HTTPS is a prerequisite for HTTP/2 and many new web platform APIs.
Insecure URL Request Resolution
http://codesandbox.io/
Allowed

Audits

Displays images with incorrect aspect ratio
Ensure that image display dimensions match their natural aspect ratio.
URL Aspect Ratio (Displayed) Aspect Ratio (Actual)
https://codesandbox.io/static/2-10e160af8df5b999b208ad1a06524851.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/8-83c1510a0f2ee1d4111c83620eca3c8b.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/6-b8729491b135980c18dfb49dc36e2b27.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/10-e9fb046f76b332880a7bfa2e21b1992a.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/3-43bdf1192e6cee5f46576e57f6272bc0.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/1-57a3aceaa9f87c219006b02398fe1aa7.png
324 x 570 (0.57)
712 x 1158 (0.61)
https://codesandbox.io/static/7-c37e0c5e9adae98b18b750c28fd2e1ed.png
324 x 570 (0.57)
356 x 579 (0.61)

Audits

Browser errors were logged to the console
Below is a list of all errors logged to the console, which indicate unresolved problems on the site.
Source Description
SHOW DETAILS
Failed to load resource: net::ERR_CONNECTION_FAILED
96

SEO

Indicates how well the page is optimized for ranking in search engines and highlights Search Engine Optimization (SEO) opportunities for codesandbox.io. This includes optimizations such as providing meta data.

Mobile Friendly

Has a `<meta name="viewport">` tag with `width` or `initial-scale`
It is advised to use a '<meta name="viewport">' tag for the optimization of codesandbox.io on mobile screens.
Document uses legible font sizes — 100% legible text
Font sizes of 12px or less are too small to most mobile users without user gestures and further action. Aim for more than 60% of page text to use font sizes greater than 12px.
Source Selector % of Page Text Font Size
SHOW DETAILS
100.00%
≥ 12px

Content Best Practices

Document has a `<title>` element
Search engines, screen reader users and other assistive technology users rely on the title to provide an overview of the page and to help determine if the page is relevant to their search.
Document has a meta description
Meta descriptions may be used by search engines when displaying a link to the page and should concisely summarize the page's content.
Links have descriptive text
Make use of descriptive link text to assist search engines in understanding the content.
Image elements have `[alt]` attributes
Provide short and descriptive alternative text where possible on informative elements.
Document has a valid `hreflang`
Search engines can be instructed to list specific versions of a page for a given language or region through the use of hreflang links.
Document has a valid `rel=canonical`
Search engines can be suggested which URL should be shown in search results through the use of canonical links.
Document avoids plugins
The content of plugins cannot be indexed by search engines and many devices either restrict or do not support them.

Crawling and Indexing

Page has successful HTTP status code
Avoid pages with unsuccessful HTTP status codes as they may not be indexed by search engines.
Links are crawlable
Ensure that the 'href' attribute of anchor elements links to the appropriate destination. This allows for more pages of the site to be discovered by search engines.
Page isn’t blocked from indexing
Pages that cannot be crawled by search engines cannot be indexed or included in their search results. Ensure that search engines have permission to crawl all pages that should be indexed.
robots.txt is valid
Malformed robots.txt files prevent crawlers from understanding how a site wants to be crawled or indexed, which can be devastating to SEO.

Mobile Friendly

Tap targets are not sized appropriately — 50% appropriately sized tap targets
Interactive elements (such as buttons and links) should be appropriately spaced, sized and easy enough to select or tap with regard to their surrounding elements.
Tap Target Size Overlapping Target
Blog
28x16
Company
Blog
28x16
Podcasts
Teams
41x16
Individuals
Teams
41x16
Enterprise
Status
41x16
Contact Support
Pricing
43x16
Company
Coding
44x16
Prototyping
Prototyping
74x16
Knowledge Sharing
Feedback
60x16
Knowledge Sharing
Feedback
60x16
What’s New
Featured Sandboxes
69x16
Search Sandboxes
Careers
48x16
Podcasts
Careers
48x16
Terms Of Use
Terms Of Use
82x16
Privacy Policy
Documentation
96x16
Contact Support

Manual Checks

Structured data is valid
Structured data can be validated through the use of the Structured Data Testing Tool and the Structured Data Linter.
42

Progressive Web App

Indicates how valid the aspects of a Progressive Web App (PWA) are for the page and highlights opportunities to enable/improve the PWA of codesandbox.io. This includes details about web app manifests.

PWA Optimized

Redirects HTTP traffic to HTTPS
It is advised to redirect all HTTP traffic to HTTPS, in order to enable secure web features for all users.
Content is sized correctly for the viewport
Ensure that the width of the app's content matches the width of the viewport, otherwise the app might not be optimized for mobile screens.
Has a `<meta name="viewport">` tag with `width` or `initial-scale`
It is advised to use a '<meta name="viewport">' tag for the optimization of codesandbox.io on mobile screens.

Installable

Web app manifest or service worker do not meet the installability requirements — 1 reason
User engagement may be increased by leveraging the browsers ability to proactively prompt users to add the app to their homescreen.
Failure reason
No manifest was fetched

PWA Optimized

Does not register a service worker that controls page and `start_url`
A service worker is used to provide Progressive Web Apps the use of features such as working offline, the ability for the app to be added to the homescreen as well as push notifications.
Is not configured for a custom splash screen
Themed splash screens ensure a high-quality user experience at launch for app users.
View Data
Does not set a theme color for the address bar.
A theme may be applied to the browser address bar, which ideally can be made to match the site.
View Data
Does not provide a valid `apple-touch-icon`
iOS users of Progressive Web Apps will benefit from an apple touch icon, which can be defined with 'apple-touch-icon', which must point to a non-transparent 192px (or 180px) square PNG.
Manifest doesn't have a maskable icon
Maskable icons are great to ensure that images fill the entire shape when installing the app on a device.

Manual Checks

Site works cross-browser
Ensure that the Progressive Web App works correctly across every major browser.
Page transitions don't feel like they block on the network
Users perceive apps with responsive, snappy transitions as higher peforming and ensures a great user experience, even on a slow network.
Each page has a URL
Ensure that all pages are deep linkable via URL. They should also be unique for the purpose of shareability on social media.
Hosting

Server Location

Server IP Address: 104.18.43.9
Continent:
Country:
Region:
City:
Longitude:
Latitude:
Currencies:
Languages:

Web Hosting Provider

Name IP Address
Cloudflare, Inc.
Registration

Domain Registrant

Private Registration: Yes
Name:
Organization: Privacy service provided by Withheld for Privacy ehf
Country: IS
City:
State: Capital Region
Post Code:
Email:
Phone:
Note: Registration information is derived from various sources and may be inaccurate.

Domain Registrar

Name IP Address
NameCheap, Inc. 104.16.99.56
Security

Visitor Safety

Mature Content: Not Likely
McAfee WebAdvisor Rating: Unknown
WOT Rating:
WOT Trustworthiness: 64/100
WOT Child Safety: 100/100
Note: Safety information is not guaranteed.

SSL/TLS Certificate

Issued To: codesandbox.io
Issued By: Cloudflare Inc ECC CA-3
Valid From: 19th May, 2021
Valid To: 18th May, 2022
Subject: CN = codesandbox.io
O = Cloudflare, Inc.
L = San Francisco
S = US
Hash: cc534e0e
Issuer: CN = Cloudflare Inc ECC CA-3
O = Cloudflare, Inc.
S = US
Version: 2
Serial Number: 17206417462294198963037332367657517539
Serial Number (Hex): 0CF1D5E0E0EFA0A180AB71EFE3C5C1E3
Valid From: 19th May, 2025
Valid To: 18th May, 2025
Signature Algorithm (Short Name): ecdsa-with-SHA256
Signature Algorithm (Long Name): ecdsa-with-SHA256
Authority Key Identifier: keyid:A5:CE:37:EA:EB:B0:75:0E:94:67:88:B4:45:FA:D9:24:10:87:96:1F
Extended Key Usage: TLS Web Server Authentication, TLS Web Client Authentication
CRL Distribution Points:
Full Name:
URI:http://crl3.digicert.com/CloudflareIncECCCA-3.crl

Full Name:
URI:http://crl4.digicert.com/CloudflareIncECCCA-3.crl
Certificate Policies: Policy: 2.23.140.1.2.2
CPS: http://www.digicert.com/CPS
Authority Information Access: OCSP - URI:http://ocsp.digicert.com
CA Issuers - URI:http://cacerts.digicert.com/CloudflareIncECCCA-3.crt
SCT List: Signed Certificate Timestamp:
Version : v1 (0x0)
Log ID : 29:79:BE:F0:9E:39:39:21:F0:56:73:9F:63:A5:77:E5:
BE:57:7D:9C:60:0A:F8:F9:4D:5D:26:5C:25:5D:C7:84
Timestamp : May 19 18:38:50.330 2021 GMT
Extensions: none
Signature : ecdsa-with-SHA256
30:45:02:21:00:94:AD:E8:32:CD:D8:66:AA:B6:BC:E2:
21:BF:6C:32:DA:69:2B:0B:A3:6E:7E:D0:05:34:C2:86:
09:DC:F2:99:57:02:20:0C:03:13:9E:BE:C2:F6:9E:39:
66:CB:94:12:0E:82:0D:EB:58:75:EC:3A:3B:E1:58:42:
79:2A:29:2C:97:C8:8D
Signed Certificate Timestamp:
Version : v1 (0x0)
Log ID : 22:45:45:07:59:55:24:56:96:3F:A1:2F:F1:F7:6D:86:
E0:23:26:63:AD:C0:4B:7F:5D:C6:83:5C:6E:E2:0F:02
Timestamp : May 19 18:38:50.416 2021 GMT
Extensions: none
Signature : ecdsa-with-SHA256
30:46:02:21:00:92:82:93:E2:A2:5C:F8:56:CC:D3:48:
28:2D:77:1F:1F:1E:64:F4:07:52:17:8A:09:07:83:E5:
F4:AA:35:0B:0D:02:21:00:C2:17:5D:90:EF:4C:54:EE:
94:CC:04:B3:5D:08:C9:B6:E1:4F:71:9D:EE:EA:E8:99:
30:89:2F:43:BE:C8:79:D6
Signed Certificate Timestamp:
Version : v1 (0x0)
Log ID : 41:C8:CA:B1:DF:22:46:4A:10:C6:A1:3A:09:42:87:5E:
4E:31:8B:1B:03:EB:EB:4B:C7:68:F0:90:62:96:06:F6
Timestamp : May 19 18:38:50.388 2021 GMT
Extensions: none
Signature : ecdsa-with-SHA256
30:44:02:20:37:3B:2A:B5:C8:4E:1D:05:9C:A0:43:4D:
03:2A:4B:B8:29:E1:10:78:69:A3:64:BD:24:18:6C:3A:
B6:E0:AF:43:02:20:59:54:90:B0:AC:EC:84:3D:C2:BF:
4E:95:9F:E5:5E:72:6E:C5:10:05:64:E6:87:94:5A:D8:
A0:44:E2:9F:56:DA
Key Usage: Digital Signature
Basic Constraints: CA:FALSE
Subject Alternative Name: DNS:*.codesandbox.io
DNS:*.sse.codesandbox.io
DNS:sse.codesandbox.io
DNS:codesandbox.io
Technical

DNS Lookup

HTTP Response Headers

HTTP-Code: HTTP/1.1 200 OK
Date: 8th June, 2021
Content-Type: text/html
Cache-Control: no-cache
Expires: 1st January, 1970
Server: cloudflare
Connection: keep-alive
CF-Ray: 65c111699c821bd8-EWR
Access-Control-Allow-Origin: *
Last-Modified: 8th June, 2021
Vary: Accept-Encoding
Via: 1.1 google
CF-Cache-Status: DYNAMIC
Access-Control-Allow-Methods: GET
Alt-Svc: h3-27=":443"; ma=86400, h3-28=":443"; ma=86400, h3-29=":443"; ma=86400, h3=":443"; ma=86400
cf-request-id: 0a8c8935fe00001bd86338b000000001
Expect-CT: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"

Whois Lookup

Created: 23rd November, 2016
Changed: 26th October, 2020
Expires: 23rd November, 2029
Registrar: NameCheap, Inc
Status: clientTransferProhibited
Nameservers: adel.ns.cloudflare.com
greg.ns.cloudflare.com
Owner Organization: Privacy service provided by Withheld for Privacy ehf
Owner State: Capital Region
Owner Country: IS
Full Whois: Domain Name: CODESANDBOX.IO
Registry Domain ID: D503300000040333757-LRMS
Registrar WHOIS Server: whois.namecheap.com
Registrar URL: www.namecheap.com
Updated Date: 2020-10-26T09:50:38Z
Creation Date: 2016-11-23T16:45:43Z
Registry Expiry Date: 2029-11-23T16:45:43Z
Registrar Registration Expiration Date:
Registrar: NameCheap, Inc
Registrar IANA ID: 1068
Registrar Abuse Contact Email: abuse@namecheap.com
Registrar Abuse Contact Phone: +1.6613102107
Reseller:
Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited
Registrant Organization: Privacy service provided by Withheld for Privacy ehf
Registrant State/Province: Capital Region
Registrant Country: IS
Name Server: GREG.NS.CLOUDFLARE.COM
Name Server: ADEL.NS.CLOUDFLARE.COM
DNSSEC: unsigned

>>> Last update of WHOIS database: 2021-06-08T09:23:37Z <<<

For more information on Whois status codes, please visit https://icann.org/epp

Access to WHOIS information provided by Internet Computer Bureau Ltd. ("ICB") is provided to assist persons in determining the contents of a domain name registration record in the ICB registry database. The data in this record is provided by ICB for informational purposes only, and ICB does not guarantee its accuracy. This service is intended only for query-based access. You agree that you will use this data only for lawful purposes and that, under no circumstances will you use this data to(i) allow, enable, or otherwise support the transmission by e-mail, telephone, facsimile or other electronic means of mass, unsolicited, commercial advertising or solicitations to entities other than the data recipient's own existing customers; or (ii) enable high volume, automated, electronic processes that send queries or data to the systems of Registry Operator, a Registrar, or ICB or its services providers except as reasonably necessary to register domain names or modify existing registrations. UK privacy laws limit the scope of information permitted for certain public access. Therefore, concerns regarding abusive use of domain registrations in the ICB registry should be directed to either (a) the Registrar of Record as indicated in the WHOIS output, or (b) the ICB anti-abuse department at abuse@icbregistry.info.

All rights reserved. ICB reserves the right to modify these terms at any time. By submitting this query, you agree to abide by these policies

The Registrar of Record identified in this output may have an RDDS service that can be queried for additional information on how to contact the Registrant, Admin, or Tech contact of the queried domain name.
View Raw Whois

Nameservers

Name IP Address
adel.ns.cloudflare.com 173.245.58.55
greg.ns.cloudflare.com 172.64.33.115
Related

Subdomains

Similar Sites

Organic Search (US) Competitors

Backlink Competitors

Sites with the same domain name

Domain Valuation Snoop Score
codesandbox.com
0/5

Sites hosted on the same IP address

Domain Valuation Snoop Score
biterflow.com
0/5
Love W3 Snoop?
Update Now

codesandbox.io Infographic

codesandbox.io by the numbers infographic

Recently Updated

games.com
github.com
unlocktool.net
7starhd.bike
camwhores.in
camwhores.fans
full4movies.de
spotify.com
9anime.com
snapchat.com

Recently Viewed

rattleme.com
mqvxub.com
middleclassinvestor.com
peninrome.com
mainebeachouse.com
qchi.com
nationaldefaultexchange.com
robo-tar.com
6502asm.com
popdiscourse.com