Spain · Madrid Completed: Apr 7, 2026 20:13 UTCMobile 375 × 812
Desktop 1440 × 900
Score: 68 / 100
Based on 8 categories, 0 sections
The overall score is a weighted average of individual category scores. Categories with more impact on user experience and security carry more weight.
Weights reflect general web best practices. Individual needs may differ.
Content-Security-Policy header is missing
Cookie '_fs_ch_st_FSBmUei20MqUiJb9' is missing the Secure flag
HSTS header is missing
No Content-Security-Policy header found
No <main> landmark found
[](https://beavercheck.com/results/15411427-b0dd-504b-7a6c-fb22a1117eea)<a href="https://beavercheck.com/results/15411427-b0dd-504b-7a6c-fb22a1117eea"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fwww.khanacademy.org" alt="BeaverCheck Score"></a>https://beavercheck.com/badge?url=https%3A%2F%2Fwww.khanacademy.orgThis badge auto-updates with your latest scan result.
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Industry-standard audits powered by Google Lighthouse.
Key metrics that affect user experience.
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
6.43 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
10.12 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
658 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.43 s
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
10.47 s
Audit breakdown by category with detailed findings.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
| URL | Transfer Size | Duration |
|---|---|---|
| cdn.kastatic.org/khanacademy/khanacademy.d010d00049edb0e5.js | 715.6 KiB | 3.6 s |
| cdn.kastatic.org/khanacademy/khanacademy.753cf3d0cb0bd8f2.css | 10.3 KiB | 754 ms |
| cdn.kastatic.org/khanacademy/runtime.402cbd25dcfa78ca.js | 13.7 KiB |
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
| Request | Cache TTL | Transfer Size |
|---|---|---|
| /api/badges/download-on-the-app-store/black/en-us?release... | 604800.0 s | 11.3 KiB |
Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.
| URL | Est Savings |
|---|---|
| cdn.kastatic.org/khanacademy/fonts/1cf13853095a62e2-LatoLatin-Bold.woff2 | 10 ms |
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
| URL | Resource Size | Est Savings | |
|---|---|---|---|
div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 | cdn.kastatic.org/images/lohp/faces_collage_2@2x.png | 666.4 KiB | 623.2 KiB |
Learners
Teachers
Parents
Back div._vtegui > div._e296pg > div#last-chance-lohp > div._18iqadbp | cdn.kastatic.org/images/lohp/last_chance_collage@2x.png | 373.4 KiB | 177.1 KiB |
div._e296pg > div._mg36wky > div._et3ir1 > img._1k6dqj1 div._e296pg > div._mg36wky > div._et3ir1 > img._1k6dqj1 | cdn.kastatic.org/images/lohp/laptop_collage@2x.png | 181.6 KiB | 138.7 KiB |
div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 | cdn.kastatic.org/images/lohp/math-unicorn-donate-collage.png | 158.3 KiB | 120.7 KiB |
div._8iuiziq > div._1wqqgcad > div._46s8e9s > img._1k6dqj1 div._8iuiziq > div._1wqqgcad > div._46s8e9s > img._1k6dqj1 | cdn.kastatic.org/images/lohp/anjali-3.png | 75.7 KiB | 70.2 KiB |
Get it on Google Play ul > li._ouyp5ih > a._wilhdph > img._1iym5ly | cdn.kastatic.org/images/store-badges/google-play/en.png | 5.9 KiB | 5.3 KiB |
Bill and Melinda Gates Foundation div._51yg8mt > div._vuhkxie > div._1t9h51bq > img._55m9r6s | cdn.kastatic.org/images/supporters-logos/gates-foundation-dark-gray@2x.png | 8.2 KiB | 5.2 KiB |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.
Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
| URL | Transfer Size | Est Savings |
|---|---|---|
| cdn.kastatic.org/khanacademy/khanacademy.d010d00049edb0e5.js | 709.0 KiB | 395.8 KiB |
| www.googletagmanager.com/gtm.js?id=GTM-WSX5PBP | 150.7 KiB | 87.4 KiB |
| cdn.kastatic.org/khanacademy/36639.dbefd49b0f07f21d.js | 33.7 KiB | 25.2 KiB |
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.
| URL | Total CPU Time | Script Evaluation | Script Parse |
|---|---|---|---|
| cdn.kastatic.org/khanacademy/khanacademy.d010d00049edb0e5.js | 1.6 s | 1.3 s | 193 ms |
| Unattributable | 436 ms | 40 ms | 0.0 ms |
| www.khanacademy.org/ | 319 ms | 33 ms | 29 ms |
| cdn.kastatic.org/khanacademy/82289.7eff447bec28ae13.js | 201 ms | 167 ms | 2.5 ms |
| www.googletagmanager.com/gtm.js?id=GTM-WSX5PBP | 136 ms | 92 ms | 43 ms |
Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work
| Category | Time Spent |
|---|---|
| Script Evaluation | 1.6 s |
| Other | 498 ms |
| Script Parsing & Compilation | 315 ms |
| Style & Layout | 306 ms |
| Rendering | 50 ms |
| Parse HTML & CSS | 20 ms |
| Garbage Collection | 15 ms |
Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache
| Failure reason | Failure type |
|---|---|
| Pages with cache-control:no-store header cannot enter back/forward cache. | Actionable |
| Pages whose main resource has cache-control:no-store cannot enter back/forward cache. | Not actionable |
| Back/forward cache is disabled because some JavaScript network request received resource with Cache-Control: no-store header. | Not actionable |
Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
| URL | |
|---|---|
div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 | cdn.kastatic.org/images/lohp/faces_collage_2@2x.png |
div._e296pg > div._mg36wky > div._et3ir1 > img._1k6dqj1 div._e296pg > div._mg36wky > div._et3ir1 > img._1k6dqj1 | cdn.kastatic.org/images/lohp/laptop_collage@2x.png |
div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 | cdn.kastatic.org/images/lohp/math-unicorn-donate-collage.png |
Get it on Google Play ul > li._ouyp5ih > a._wilhdph > img._1iym5ly | cdn.kastatic.org/images/store-badges/google-play/en.png |
div._8iuiziq > div._1wqqgcad > div._46s8e9s > img._1k6dqj1 div._8iuiziq > div._1wqqgcad > div._46s8e9s > img._1k6dqj1 | cdn.kastatic.org/images/lohp/anjali-3.png |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._14srqcp div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._14srqcp | cdn.kastatic.org/images/lohp/trusted_content_icon.png |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 | cdn.kastatic.org/images/lohp/personalized_learning_icon.png |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 | cdn.kastatic.org/images/lohp/empower_teachers_icon.png |
Download on the App Store ul > li._ouyp5ih > a._wilhdph > img._1iym5ly | /api/badges/download-on-the-app-store/black/en-us?release... |
More information about the performance of your application. These numbers don't directly affect the Performance score.
These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.
Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.
| Failing Elements |
|---|
English div._s6za34 > div._1bvnlzk > div._6kyiev1 > button#:r2: |
Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit
| Source | Description |
|---|---|
cdn.kastatic.org/khanacademy/khanacademy.d010d00049edb0e5.js line 508, col 147429 | Uncaught (in promise) KANotFoundError: Failed to load https://cdn.cookielaw.org/scripttemplates/otSDKStub.js. |
These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.
If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed. Learn more about robots.txt.
| Line # | Content | Error |
|---|---|---|
| 1 | <!DOCTYPE html> | Syntax not understood |
| 2 | <html lang="en"> | Syntax not understood |
| 3 | <head> | Syntax not understood |
| 4 | <meta | Syntax not understood |
| 5 | http-equiv="Content-Security-Policy" | Syntax not understood |
| 6 | content="default-src 'self'; img-src 'self' data:; media-src 'self' data:; object-src 'none'; style-src 'self' 'sha256-o4vzfmmUENEg4chMjjRP9EuW9ucGnGIGVdbl8d0SHQQ='; script-src 'self' 'sha256-KXex2o39zxtnzVWK4H5rW07g2+BlwSPtn+aguzsWkNg=';" | Unknown directive |
| 7 | /> | Syntax not understood |
| 8 | <link | Syntax not understood |
| 9 | href="/_fs-ch-1T1wmsGaOgGaSxcX/assets/inter-var.woff2" | Syntax not understood |
| 10 | rel="preload" | Syntax not understood |
| 11 | as="font" | Syntax not understood |
| 12 | type="font/woff2" | Syntax not understood |
| 13 | crossorigin | Syntax not understood |
| 14 | /> | Syntax not understood |
| 15 | <link href="/_fs-ch-1T1wmsGaOgGaSxcX/assets/styles.css" rel="stylesheet" /> | Syntax not understood |
| 16 | <meta name="viewport" content="width=device-width, initial-scale=1" /> | Syntax not understood |
| 17 | <title>Client Challenge</title> | Syntax not understood |
| 18 | <style> | Syntax not understood |
| 20 | font-size: 16px; | Unknown directive |
| 21 | font-family: 'Inter', sans-serif; | Unknown directive |
| 22 | margin-top: 10px; | Unknown directive |
| 23 | margin-left: 10px; | Unknown directive |
| 24 | display: none; | Unknown directive |
| 25 | } | Syntax not understood |
| 26 | </style> | Syntax not understood |
| 27 | </head> | Syntax not understood |
| 28 | <body> | Syntax not understood |
| 29 | <noscript> | Syntax not understood |
| 30 | <div class="noscript-container"> | Syntax not understood |
| 31 | <div class="noscript-content"> | Syntax not understood |
| 32 | <img | Syntax not understood |
| 33 | src="/_fs-ch-1T1wmsGaOgGaSxcX/assets/errorIcon.svg" | Syntax not understood |
| 34 | alt="" | Syntax not understood |
| 35 | role="presentation" | Syntax not understood |
| 36 | class="error-icon" | Syntax not understood |
| 37 | /> | Syntax not understood |
| 38 | <span class="noscript-span" | Syntax not understood |
| 39 | >JavaScript is disabled in your browser.</span | Syntax not understood |
| 40 | > | Syntax not understood |
| 41 | <p>Please enable JavaScript to proceed.</p> | Syntax not understood |
| 42 | </div> | Syntax not understood |
| 43 | </div> | Syntax not understood |
| 44 | </noscript> | Syntax not understood |
| 45 | <div id="loading-error" role="alert" aria-live="polite"> | Syntax not understood |
| 46 | A required part of this site couldn’t load. This may be due to a browser | Syntax not understood |
| 47 | extension, network issues, or browser settings. Please check your | Syntax not understood |
| 48 | connection, disable any ad blockers, or try using a different browser. | Syntax not understood |
| 49 | </div> | Syntax not understood |
| 50 | <script> | Syntax not understood |
| 51 | function loadScript(src) { | Syntax not understood |
| 52 | return new Promise((resolve, reject) => { | Syntax not understood |
| 53 | const script = document.createElement('script'); | Syntax not understood |
| 54 | script.onload = resolve; | Syntax not understood |
| 55 | script.onerror = (event) => { | Syntax not understood |
| 56 | console.error('Script load error event:', event); | Unknown directive |
| 57 | document.getElementById('loading-error').style.display = 'block'; | Syntax not understood |
| 58 | loadingError.setAttribute('aria-hidden', 'false'); | Syntax not understood |
| 59 | reject( | Syntax not understood |
| 60 | new Error( | Syntax not understood |
| 61 | `Failed to load script: ${src}, Please contact the service administrator.` | Unknown directive |
| 62 | ) | Syntax not understood |
| 63 | ); | Syntax not understood |
| 64 | }; | Syntax not understood |
| 65 | script.src = src; | Syntax not understood |
| 66 | document.body.appendChild(script); | Syntax not understood |
| 67 | }); | Syntax not understood |
| 68 | } | Syntax not understood |
| 70 | loadScript('/_fs-ch-1T1wmsGaOgGaSxcX/errors.js') | Syntax not understood |
| 71 | .then(() => { | Syntax not understood |
| 72 | const script = document.createElement('script'); | Syntax not understood |
| 73 | script.src = '/_fs-ch-1T1wmsGaOgGaSxcX/script.js?reload=true'; | Syntax not understood |
| 74 | script.onerror = (event) => { | Syntax not understood |
| 75 | console.error('Script load error event:', event); | Unknown directive |
| 76 | const errorMsg = new Error( | Syntax not understood |
| 77 | `Failed to load script: ${script.src}. Please contact the service administrator.` | Unknown directive |
| 78 | ); | Syntax not understood |
| 79 | console.error(errorMsg); | Syntax not understood |
| 80 | handleScriptError(); | Syntax not understood |
| 81 | }; | Syntax not understood |
| 82 | document.body.appendChild(script); | Syntax not understood |
| 83 | }) | Syntax not understood |
| 84 | .catch((error) => { | Syntax not understood |
| 85 | console.error(error); | Syntax not understood |
| 86 | }); | Syntax not understood |
| 87 | </script> | Syntax not understood |
| 88 | </body> | Syntax not understood |
| 89 | </html> | Syntax not understood |
To appear in search results, crawlers need access to your app.
Industry-standard audits powered by Google Lighthouse. — Desktop
Key metrics that affect user experience. — Desktop
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
1.52 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.37 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
120 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.010
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.81 s
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
2.43 s
Audit breakdown by category with detailed findings.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
A forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.
Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading
Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
| URL | Transfer Size | Duration |
|---|---|---|
| cdn.kastatic.org/khanacademy/khanacademy.d010d00049edb0e5.js | 715.7 KiB | 560 ms |
| cdn.kastatic.org/khanacademy/runtime.402cbd25dcfa78ca.js | 13.7 KiB | |
| cdn.kastatic.org/khanacademy/khanacademy.753cf3d0cb0bd8f2.css | 10.3 KiB | 200 ms |
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
| Request | Cache TTL | Transfer Size |
|---|---|---|
| /api/badges/download-on-the-app-store/black/en-us?release... | 604800.0 s | 11.3 KiB |
Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
| URL | Resource Size | Est Savings | |
|---|---|---|---|
div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 | cdn.kastatic.org/images/lohp/faces_collage_2@2x.png | 666.4 KiB | 618.9 KiB |
div._1s6u9f56 > div._8plbkmf > div._1lnhlk8u > img._82vv51 div._1s6u9f56 > div._8plbkmf > div._1lnhlk8u > img._82vv51 | cdn.kastatic.org/images/lohp/boost-scores.png | 210.2 KiB | 180.0 KiB |
div._e296pg > div._mg36wky > div._et3ir1 > img._1k6dqj1 div._e296pg > div._mg36wky > div._et3ir1 > img._1k6dqj1 | cdn.kastatic.org/images/lohp/laptop_collage@2x.png | 181.6 KiB | 134.5 KiB |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 | cdn.kastatic.org/images/lohp/empower_teachers_icon.png | 9.0 KiB | 7.3 KiB |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 | cdn.kastatic.org/images/lohp/personalized_learning_icon.png | 8.8 KiB | 7.0 KiB |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._14srqcp div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._14srqcp | cdn.kastatic.org/images/lohp/trusted_content_icon.png | 9.1 KiB | 7.0 KiB |
| cdn.kastatic.org/images/store-badges/google-play/en.png | 5.9 KiB | 5.7 KiB |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
| URL | Transfer Size | Est Savings |
|---|---|---|
| cdn.kastatic.org/khanacademy/khanacademy.d010d00049edb0e5.js | 709.1 KiB | 395.8 KiB |
| www.googletagmanager.com/gtm.js?id=GTM-WSX5PBP | 150.7 KiB | 87.4 KiB |
| cdn.kastatic.org/khanacademy/36639.dbefd49b0f07f21d.js | 33.7 KiB | 25.2 KiB |
Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache
| Failure reason | Failure type |
|---|---|
| Pages with cache-control:no-store header cannot enter back/forward cache. | Actionable |
| Pages whose main resource has cache-control:no-store cannot enter back/forward cache. | Not actionable |
| Back/forward cache is disabled because some JavaScript network request received resource with Cache-Control: no-store header. | Not actionable |
Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
| URL | |
|---|---|
div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 | cdn.kastatic.org/images/lohp/faces_collage_2@2x.png |
div._e296pg > div._mg36wky > div._et3ir1 > img._1k6dqj1 div._e296pg > div._mg36wky > div._et3ir1 > img._1k6dqj1 | cdn.kastatic.org/images/lohp/laptop_collage@2x.png |
div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 div._e296pg > div._1b4n03jl > div._hoh1o6o > img._1k6dqj1 | cdn.kastatic.org/images/lohp/math-unicorn-donate-collage.png |
div._1s6u9f56 > div._8plbkmf > div._1lnhlk8u > img._82vv51 div._1s6u9f56 > div._8plbkmf > div._1lnhlk8u > img._82vv51 | cdn.kastatic.org/images/lohp/boost-scores.png |
Get it on Google Play ul > li._ouyp5ih > a._wilhdph > img._1iym5ly | cdn.kastatic.org/images/store-badges/google-play/en.png |
div._8iuiziq > div._1wqqgcad > div._46s8e9s > img._1k6dqj1 div._8iuiziq > div._1wqqgcad > div._46s8e9s > img._1k6dqj1 | cdn.kastatic.org/images/lohp/anjali-3.png |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._14srqcp div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._14srqcp | cdn.kastatic.org/images/lohp/trusted_content_icon.png |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 | cdn.kastatic.org/images/lohp/personalized_learning_icon.png |
div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 div._3vgeo5o > div._5hffmqw > div._xnpl0ze > img._zdxht7 | cdn.kastatic.org/images/lohp/empower_teachers_icon.png |
Download on the App Store ul > li._ouyp5ih > a._wilhdph > img._1iym5ly | /api/badges/download-on-the-app-store/black/en-us?release... |
More information about the performance of your application. These numbers don't directly affect the Performance score.
These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.
Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.
| Failing Elements |
|---|
English div._s6za34 > div._1bvnlzk > div._6kyiev1 > button#:r2: |
Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit
| Source | Description |
|---|---|
cdn.kastatic.org/khanacademy/khanacademy.d010d00049edb0e5.js line 508, col 147429 | Uncaught (in promise) KANotFoundError: Failed to load https://cdn.cookielaw.org/scripttemplates/otSDKStub.js. |
These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.
If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed. Learn more about robots.txt.
| Line # | Content | Error |
|---|---|---|
| 1 | <!DOCTYPE html> | Syntax not understood |
| 2 | <html lang="en"> | Syntax not understood |
| 3 | <head> | Syntax not understood |
| 4 | <meta | Syntax not understood |
| 5 | http-equiv="Content-Security-Policy" | Syntax not understood |
| 6 | content="default-src 'self'; img-src 'self' data:; media-src 'self' data:; object-src 'none'; style-src 'self' 'sha256-o4vzfmmUENEg4chMjjRP9EuW9ucGnGIGVdbl8d0SHQQ='; script-src 'self' 'sha256-KXex2o39zxtnzVWK4H5rW07g2+BlwSPtn+aguzsWkNg=';" | Unknown directive |
| 7 | /> | Syntax not understood |
| 8 | <link | Syntax not understood |
| 9 | href="/_fs-ch-1T1wmsGaOgGaSxcX/assets/inter-var.woff2" | Syntax not understood |
| 10 | rel="preload" | Syntax not understood |
| 11 | as="font" | Syntax not understood |
| 12 | type="font/woff2" | Syntax not understood |
| 13 | crossorigin | Syntax not understood |
| 14 | /> | Syntax not understood |
| 15 | <link href="/_fs-ch-1T1wmsGaOgGaSxcX/assets/styles.css" rel="stylesheet" /> | Syntax not understood |
| 16 | <meta name="viewport" content="width=device-width, initial-scale=1" /> | Syntax not understood |
| 17 | <title>Client Challenge</title> | Syntax not understood |
| 18 | <style> | Syntax not understood |
| 20 | font-size: 16px; | Unknown directive |
| 21 | font-family: 'Inter', sans-serif; | Unknown directive |
| 22 | margin-top: 10px; | Unknown directive |
| 23 | margin-left: 10px; | Unknown directive |
| 24 | display: none; | Unknown directive |
| 25 | } | Syntax not understood |
| 26 | </style> | Syntax not understood |
| 27 | </head> | Syntax not understood |
| 28 | <body> | Syntax not understood |
| 29 | <noscript> | Syntax not understood |
| 30 | <div class="noscript-container"> | Syntax not understood |
| 31 | <div class="noscript-content"> | Syntax not understood |
| 32 | <img | Syntax not understood |
| 33 | src="/_fs-ch-1T1wmsGaOgGaSxcX/assets/errorIcon.svg" | Syntax not understood |
| 34 | alt="" | Syntax not understood |
| 35 | role="presentation" | Syntax not understood |
| 36 | class="error-icon" | Syntax not understood |
| 37 | /> | Syntax not understood |
| 38 | <span class="noscript-span" | Syntax not understood |
| 39 | >JavaScript is disabled in your browser.</span | Syntax not understood |
| 40 | > | Syntax not understood |
| 41 | <p>Please enable JavaScript to proceed.</p> | Syntax not understood |
| 42 | </div> | Syntax not understood |
| 43 | </div> | Syntax not understood |
| 44 | </noscript> | Syntax not understood |
| 45 | <div id="loading-error" role="alert" aria-live="polite"> | Syntax not understood |
| 46 | A required part of this site couldn’t load. This may be due to a browser | Syntax not understood |
| 47 | extension, network issues, or browser settings. Please check your | Syntax not understood |
| 48 | connection, disable any ad blockers, or try using a different browser. | Syntax not understood |
| 49 | </div> | Syntax not understood |
| 50 | <script> | Syntax not understood |
| 51 | function loadScript(src) { | Syntax not understood |
| 52 | return new Promise((resolve, reject) => { | Syntax not understood |
| 53 | const script = document.createElement('script'); | Syntax not understood |
| 54 | script.onload = resolve; | Syntax not understood |
| 55 | script.onerror = (event) => { | Syntax not understood |
| 56 | console.error('Script load error event:', event); | Unknown directive |
| 57 | document.getElementById('loading-error').style.display = 'block'; | Syntax not understood |
| 58 | loadingError.setAttribute('aria-hidden', 'false'); | Syntax not understood |
| 59 | reject( | Syntax not understood |
| 60 | new Error( | Syntax not understood |
| 61 | `Failed to load script: ${src}, Please contact the service administrator.` | Unknown directive |
| 62 | ) | Syntax not understood |
| 63 | ); | Syntax not understood |
| 64 | }; | Syntax not understood |
| 65 | script.src = src; | Syntax not understood |
| 66 | document.body.appendChild(script); | Syntax not understood |
| 67 | }); | Syntax not understood |
| 68 | } | Syntax not understood |
| 70 | loadScript('/_fs-ch-1T1wmsGaOgGaSxcX/errors.js') | Syntax not understood |
| 71 | .then(() => { | Syntax not understood |
| 72 | const script = document.createElement('script'); | Syntax not understood |
| 73 | script.src = '/_fs-ch-1T1wmsGaOgGaSxcX/script.js?reload=true'; | Syntax not understood |
| 74 | script.onerror = (event) => { | Syntax not understood |
| 75 | console.error('Script load error event:', event); | Unknown directive |
| 76 | const errorMsg = new Error( | Syntax not understood |
| 77 | `Failed to load script: ${script.src}. Please contact the service administrator.` | Unknown directive |
| 78 | ); | Syntax not understood |
| 79 | console.error(errorMsg); | Syntax not understood |
| 80 | handleScriptError(); | Syntax not understood |
| 81 | }; | Syntax not understood |
| 82 | document.body.appendChild(script); | Syntax not understood |
| 83 | }) | Syntax not understood |
| 84 | .catch((error) => { | Syntax not understood |
| 85 | console.error(error); | Syntax not understood |
| 86 | }); | Syntax not understood |
| 87 | </script> | Syntax not understood |
| 88 | </body> | Syntax not understood |
| 89 | </html> | Syntax not understood |
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