Spain · Madrid Completed: Apr 16, 2026 17:58 UTCMobile 375 × 812
Desktop 1440 × 900
Score: 74 / 100
Based on 8 categories, 0 sections
Decent speed, but optimizing further could improve engagement.
Several missing protections leave your users and data exposed.
Several issues make your site difficult for assistive technology users.
Well-optimized for search — your content is discoverable.
Good server performance with room for optimization.
Mostly compliant — a few items need attention.
Good content signals with minor gaps.
Reasonable footprint with room for optimization.
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
Security gaps expose your site and users to attacks, eroding trust.
HSTS header is missing
Security gaps expose your site and users to attacks, eroding trust.
No Content-Security-Policy header found
Security gaps expose your site and users to attacks, eroding trust.
1 button(s) with no accessible text
Accessibility issues exclude users with disabilities — up to 15% of your potential audience.
1 link(s) with no accessible text
Accessibility issues exclude users with disabilities — up to 15% of your potential audience.
High impact, low effort — start here.
High impact, requires investment.
Small gains, minimal effort.
Nothing in this quadrant — good news.
Low impact, high effort — do last.
Nothing in this quadrant — good news.
[](https://beavercheck.com/results/0dcd80fe-6630-468b-a8bc-e96795a6bdeb)<a href="https://beavercheck.com/results/0dcd80fe-6630-468b-a8bc-e96795a6bdeb"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fw3schools.com" alt="BeaverCheck Score"></a>https://beavercheck.com/badge?url=https%3A%2F%2Fw3schools.comThis badge auto-updates with your latest scan result.
Your site performs reasonably well, but a few targeted fixes could meaningfully improve results. Accessibility issues exclude users who rely on assistive technology — an estimated 15% of your potential audience. Addressing the critical issues below would have the most immediate impact on your user trust.
9 barrier(s) likely increasing bounce by ~29%.
Page takes 4.5s to load
+12% bounceUsers abandon at ~3s — you're 2.0s over the 2.5s threshold
Fix: Optimize render-blocking resources, preload the hero image, and compress images
High main-thread blocking time
+2% bouncePage is non-interactive for 510ms after first paint
Fix: Defer third-party scripts and split large bundles
No HSTS header
+1% bounceReturning visitors are briefly exposed to downgrade attacks on first request
Fix: Set Strict-Transport-Security: max-age=31536000; includeSubDomains
No Content-Security-Policy header
+1% bounceHigher XSS blast radius — one compromised script can exfiltrate the checkout form
Fix: Ship a reporting-only CSP first, then enforce once violations are clean
No structured data
+2% bounceNo rich-result eligibility in Google — lower SERP CTR vs competitors with stars and prices
Fix: Add JSON-LD for your page type (Product, Article, FAQPage, LocalBusiness, …)
Content is hard to read
+2% bounceGraduate-level reading difficulty — limits the addressable audience for product or blog pages
Fix: Shorten sentences; replace jargon with plain language; target Flesch ease ≥60
7 link(s) with generic text ("click here", "read more")
+1% bounceScreen-reader users navigating by link list see no context — and search engines can't infer relevance
Fix: Rewrite with descriptive phrases that identify the destination
No skip-to-content link
+1% bounceKeyboard and screen-reader users must tab through the entire header on every page
Fix: Add a visible-on-focus <a href="#main">Skip to content</a> as the first focusable element
2 broken link(s) on the page
+3% bounceClicks land on 404s — trust drops and the session often ends
Fix: Fix or remove the broken destinations surfaced on the Content tab
Preliminary CRO audit — each barrier links to the tab with detailed analysis.
$450 investment → $3,367/month returns + USD 157,500 risk avoided
$450
4h · 5 findings
$3,367 /mo
~$40,408 / year
USD 157,500
if kept compliant
$150 — in quick wins — start here for the fastest payback
Figures combine localized regulatory fine ceilings, search/conversion value priced against local CPC, and bandwidth waste estimates. Results depend on implementation quality and audience composition. Not legal or financial advice.
4.5 developer hours at $100/hr
Based on United States rates ($100/hr)
Start here for the best return on investment
$13,125 / month at risk
~$157,504 / year if left unfixed
$157,500
+28 more
$0.35 /mo
4322.2 MB/mo × 0.080 USD/GB
Compliance figures represent the statutory maximum fine for the most severe triggered category, capped per regulation — not the sum of per-finding penalties. Based on published regulatory fine ranges. This is not legal advice.
Unique monthly visitors from your analytics
Purchases, signups, or key actions
Optional — for revenue estimation
more engaged visitors from reduced bounce
Fix 5 critical issues to capture this value
Based on Google/Deloitte research ("Milliseconds Make Millions") showing a ~7% bounce rate increase per additional second of LCP above the 2.5s "Good" threshold.
Your site's LCP: → estimated after fixes.
These are estimates based on industry research — actual results vary
Your data stays in your browser — nothing is sent to our servers
Thanks for your feedback!
We'll use a cached audit if available, or offer to scan.
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.
2.79 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
4.47 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
510 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.
2.79 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.
10.14 s
Audit breakdown by category with detailed findings.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Performance issues directly impact user engagement and conversion rates.
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
Shipping ES5 transpiled code to modern browsers wastes bytes — every user with an evergreen browser pays for compatibility you don't need.
Most users today run browsers that natively support ES6+, async/await, optional chaining, and the rest of modern JavaScript. Transpiling to ES5 'just in case' adds 20-40% to your bundle for no benefit. Configure your build to target a modern browserslist, or ship a differential bundle pair (modern + legacy) with the module/nomodule pattern.
Source: Google web.dev / Lighthouse
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
Performance issues directly impact user engagement and conversion rates.
Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Duration |
|---|---|---|
| www.w3schools.com/lib/topnav/main.v1.0.95.js | 92.0 KiB | 453 ms |
| www.w3schools.com/lib/my-learning/main.v1.0.81.js | 20.8 KiB | 151 ms |
| www.w3schools.com/lib/common-deps/main.v1.0.18.js | 9.3 KiB | |
| www.w3schools.com/lib/user-session/main.v1.0.51.js | 10.8 KiB | |
| www.w3schools.com/lib/uic.js?v=1.1.0 | 3.0 KiB | 151 ms |
| www.w3schools.com/lib/uic_prov.js?v=1.4.8 | 3.7 KiB | |
| www.w3schools.com/lib/w3schools.css?v=1.0.1 | 15.0 KiB | |
| www.w3schools.com/plus/plans/main.v1.0.3.css | 2.6 KiB | |
| www.w3schools.com/lib/pathfinder/main.v1.0.12.css | 4.5 KiB | 151 ms |
| www.w3schools.com/lib/sparteo.css?v=1.0.5 | 704 B | |
| www.w3schools.com/lib/my-learning/main.v1.0.81.css | 3.0 KiB | |
| www.w3schools.com/lib/topnav/main.v1.0.95.css | 15.9 KiB |
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
Performance issues directly impact user engagement and conversion rates.
| Request | Cache TTL | Transfer Size |
|---|---|---|
| static.fastcmp.com/fast-cmp-stub.modern.b8d64b2fce5dae2bd026.js | 800.0 s | 61.3 KiB |
| static.fastcmp.com/fast-cmp-en-tcfeuv2.82b16153b940a36e2f80.js | 800.0 s | 53.7 KiB |
| sync.sparteo.com/crossfire.js | 14400.0 s | 12.7 KiB |
| static.fastcmp.com/fast-cmp-stub.js | 800.0 s | 1.7 KiB |
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
Performance issues directly impact user engagement and conversion rates.
| URL | Resource Size | Est Savings | |
|---|---|---|---|
header.fast-cmp-layout-header > div.fast-cmp-layout-header__container > div.fast-cmp-layout-header__box > img header.fast-cmp-layout-header > div.fast-cmp-layout-header__container > div.fast-cmp-layout-header__box > img | www.w3schools.com/images/w3schools_logo_500_04AA6D.webp | 7.2 KiB | 7.0 KiB |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.
Performance issues directly impact user engagement and conversion rates.
| URL | Time Spent |
|---|---|
| w3schools.com/ | 783 ms |
| www.w3schools.com/ | 0.0 ms |
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.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.w3schools.com/lib/topnav/main.v1.0.95.js | 91.6 KiB | 25.1 KiB |
| www.w3schools.com/lib/my-learning/main.v1.0.81.js | 20.4 KiB | 6.0 KiB |
| www.w3schools.com/lib/w3schools_footer.js?update=20250924 | 14.6 KiB | 3.7 KiB |
| www.w3schools.com/lib/user-session/main.v1.0.51.js | 10.4 KiB | 2.9 KiB |
| www.w3schools.com/lib/common-deps/main.v1.0.18.js | 8.9 KiB | 2.3 KiB |
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.w3schools.com/lib/topnav/main.v1.0.95.css | 15.5 KiB | 14.5 KiB |
| www.w3schools.com/lib/w3schools.css?v=1.0.1 | 14.7 KiB | 13.4 KiB |
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
Multi-megabyte JavaScript bundles delay every interactive feature on the page.
This is the Lighthouse audit fired when too much JS is shipped relative to what executes. The fix isn't a config flag — it requires bundle analysis (webpack-bundle-analyzer, rollup-plugin-visualizer), splitting routes into chunks, lazy-loading off-screen components, and removing unused dependencies. Fundamentally different from minification: minifying reduces byte count, this reduces what's downloaded at all.
Source: Google web.dev / Lighthouse
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 361.8 KiB | 241.8 KiB |
| www.googletagmanager.com/gtag/js?id=G-9YNMTB56NB&cx=c>m=4e64f0h1 | 174.6 KiB | 70.3 KiB |
| www.w3schools.com/lib/topnav/main.v1.0.95.js | 91.6 KiB | 67.9 KiB |
| www.googletagmanager.com/gtm.js?id=GTM-KTCFC3S | 126.8 KiB | 59.4 KiB |
| static.fastcmp.com/fast-cmp-stub.modern.b8d64b2fce5dae2bd026.js | 61.2 KiB | 21.6 KiB |
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
Performance issues directly impact user engagement and conversion rates.
| Category | Time Spent |
|---|---|
| Script Evaluation | 964 ms |
| Other | 421 ms |
| Script Parsing & Compilation | 323 ms |
| Style & Layout | 253 ms |
| Parse HTML & CSS | 90 ms |
| Rendering | 54 ms |
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
Performance issues directly impact user engagement and conversion rates.
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.
Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Sign In div#pagetop > div.tnb-right-section > div#tnb-login-btn > span.button-text |
Learn HTML div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Learn CSS div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Learn JavaScript div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Learn Python div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Learn SQL div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Sign Up div.w3-row > div.w3-center > p > a#myLearningFromDefault |
Try Frontend Editor (HTML/CSS/JS) div#main > div.ws-black > div.w3-content > a.ws-btn |
Learn More div#main > div.w3-center > div > a.ws-btn |
Learn More div.w3-row > div#main > div.pro-caption > a#proFromDefault |
Learn More div.pro-caption > div.w3-content > div.w3-col > a.w3-button |
Exercises div.w3-row-padding > div.w3-half > p > a.w3-button |
Get started div#main > div#getdiploma > div > a.w3-btn |
These are opportunities to improve the legibility of your content.
Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
With the world's largest web developer site. div#main > div.ws-black > div.w3-content > h3.learntocodeh3 |
A web server programming language div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
A JS library for developing web pages div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
A programming language div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
A programming language div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
A CSS framework for faster and better responsive web pages div.w3-col > div.w3-card-2 > div > h5 |
A CSS framework for designing better web pages div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
Create an account to track your progress, get your own website,and get access t… div#main > div.w3-row > div.w3-center > h4 |
With our online code editor, you can edit code and view the result in your brow… div#main > div.ws-black > div.w3-content > h4.w3-center |
If you want to create your own website, check out W3Schools Spaces. div#main > div.w3-center > div > h3 |
No installation required - just open your browser and start coding: div#main > div.w3-center > div > h5 |
And unlock powerful features: div.w3-row > div#main > div.pro-caption > h3 |
W3Schools' famous color picker: div#main > div.w3-center > div.w3-content > h4 |
Test your skills! div.w3-row > div#main > div.w3-center > h4 |
Browse our selection of free responsive HTML Templates div.w3-row > div#main > div.w3-center > h4 |
Code snippets for HTML, CSS and JavaScript div.w3-row > div#main > div#howto_padding > h4.xxw3-text-dark-grey |
For example, how to create a slideshow: div.w3-row > div#main > div#howto_padding > h6 |
These are opportunities to improve keyboard navigation in your application.
Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. Learn more about touch targets.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
HTML Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
CSS Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
JavaScript Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
How To Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
SQL Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Python Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
W3.CSS Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Bootstrap Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
PHP Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Java Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
C++ Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
jQuery Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
HTML Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
CSS Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
JavaScript Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
SQL Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Python Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
W3.CSS Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Bootstrap Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
PHP Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
HTML Colors div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Java Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
AngularJS Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
jQuery Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
HTML Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
CSS Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
JavaScript Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
How To Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
SQL Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Python Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
W3.CSS Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Bootstrap Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
PHP Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Java Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
XML Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
jQuery Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
HTML Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
CSS Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
JavaScript Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Front End Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
SQL Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Python Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
PHP Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
jQuery Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Java Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
C++ Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
C# Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
XML Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
These items highlight common accessibility best practices.
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.
Descriptive link text helps search engines understand your content. Learn how to make links more accessible.
Performance issues directly impact user engagement and conversion rates.
| Link destination | Link Text |
|---|---|
| www.w3schools.com/go/go_exercises.php | Go |
| www.w3schools.com/go/index.php | GO |
| www.w3schools.com/go/index.php | Go |
| www.w3schools.com/spaces/index.php | Learn More |
| order.w3schools.com/plans | Learn More |
| www.w3schools.com/academy/index.php | Learn More |
Format your HTML in a way that enables crawlers to better understand your app’s content.
Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable
Performance issues directly impact user engagement and conversion rates.
| Uncrawlable Link |
|---|
div#subtopnav > div#menubtn_container > span > a.topnav-icons div#subtopnav > div#menubtn_container > span > a.topnav-icons |
body.w3s-user-anonymous > div.topnavcontainer > div#subtopnav > a body.w3s-user-anonymous > div.topnavcontainer > div#subtopnav > a |
CONTACT US div#spacemyfooter > div > div.footerlinks_1 > a |
cookies div#footerwrapper > div#spacemyfooter > div.footertext > a.ga-bottom |
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.
973 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.32 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
9 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.
1.13 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.
2.68 s
Audit breakdown by category with detailed findings.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Performance issues directly impact user engagement and conversion rates.
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
Shipping ES5 transpiled code to modern browsers wastes bytes — every user with an evergreen browser pays for compatibility you don't need.
Most users today run browsers that natively support ES6+, async/await, optional chaining, and the rest of modern JavaScript. Transpiling to ES5 'just in case' adds 20-40% to your bundle for no benefit. Configure your build to target a modern browserslist, or ship a differential bundle pair (modern + legacy) with the module/nomodule pattern.
Source: Google web.dev / Lighthouse
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
Performance issues directly impact user engagement and conversion rates.
Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
Performance issues directly impact user engagement and conversion rates.
| Request | Cache TTL | Transfer Size |
|---|---|---|
| static.fastcmp.com/fast-cmp-stub.modern.b8d64b2fce5dae2bd026.js | 800.0 s | 61.4 KiB |
| static.fastcmp.com/fast-cmp-en-tcfeuv2.82b16153b940a36e2f80.js | 800.0 s | 53.7 KiB |
| sync.sparteo.com/crossfire.js | 14400.0 s | 12.7 KiB |
| static.fastcmp.com/fast-cmp-stub.js | 800.0 s | 1.7 KiB |
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
Performance issues directly impact user engagement and conversion rates.
| URL | Resource Size | Est Savings | |
|---|---|---|---|
header.fast-cmp-layout-header > div.fast-cmp-layout-header__container > div.fast-cmp-layout-header__box > img header.fast-cmp-layout-header > div.fast-cmp-layout-header__container > div.fast-cmp-layout-header__box > img | www.w3schools.com/images/w3schools_logo_500_04AA6D.webp | 7.2 KiB | 7.1 KiB |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.
Performance issues directly impact user engagement and conversion rates.
| URL | Time Spent |
|---|---|
| w3schools.com/ | 477 ms |
| www.w3schools.com/ | 0.0 ms |
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.
Performance issues directly impact user engagement and conversion rates.
Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.w3schools.com/lib/topnav/main.v1.0.95.js | 91.6 KiB | 25.1 KiB |
| www.w3schools.com/lib/my-learning/main.v1.0.81.js | 20.4 KiB | 6.0 KiB |
| www.w3schools.com/lib/w3schools_footer.js?update=20250924 | 14.6 KiB | 3.7 KiB |
| www.w3schools.com/lib/user-session/main.v1.0.51.js | 10.4 KiB | 2.9 KiB |
| www.w3schools.com/lib/common-deps/main.v1.0.18.js | 8.9 KiB | 2.3 KiB |
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.w3schools.com/lib/topnav/main.v1.0.95.css | 15.5 KiB | 14.6 KiB |
| www.w3schools.com/lib/w3schools.css?v=1.0.1 | 14.7 KiB | 13.2 KiB |
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
Multi-megabyte JavaScript bundles delay every interactive feature on the page.
This is the Lighthouse audit fired when too much JS is shipped relative to what executes. The fix isn't a config flag — it requires bundle analysis (webpack-bundle-analyzer, rollup-plugin-visualizer), splitting routes into chunks, lazy-loading off-screen components, and removing unused dependencies. Fundamentally different from minification: minifying reduces byte count, this reduces what's downloaded at all.
Source: Google web.dev / Lighthouse
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 361.8 KiB | 241.8 KiB |
| www.googletagmanager.com/gtag/js?id=G-9YNMTB56NB&cx=c>m=4e64f0 | 174.6 KiB | 70.3 KiB |
| www.w3schools.com/lib/topnav/main.v1.0.95.js | 91.6 KiB | 67.9 KiB |
| www.googletagmanager.com/gtm.js?id=GTM-KTCFC3S | 126.8 KiB | 59.4 KiB |
| static.fastcmp.com/fast-cmp-stub.modern.b8d64b2fce5dae2bd026.js | 61.2 KiB | 21.6 KiB |
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
Performance issues directly impact user engagement and conversion rates.
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.
Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Sign In div#pagetop > div.tnb-right-section > div#tnb-login-btn > span.button-text |
Learn HTML div.w3-row > div.w3-content > div.w3-col > a.w3-button |
<!DOCTYPE html> div.w3-col > div.w3-hide-small > div.w3-code > span.doctypecolor |
Try it Yourself div.w3-content > div.w3-col > div.w3-hide-small > a.w3-button |
Learn CSS div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Try it Yourself div.w3-content > div.w3-col > div.w3-hide-small > a.w3-button |
Learn JavaScript div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Try it Yourself div.w3-content > div.w3-col > div.w3-hide-small > a.w3-button |
Learn Python div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Try it Yourself div.w3-content > div.w3-col > div.w3-hide-small > a.w3-button |
Learn SQL div.w3-row > div.w3-content > div.w3-col > a.w3-button |
Try it Yourself div.w3-content > div.w3-col > div.w3-hide-small > a.w3-button |
Sign Up div.w3-row > div.w3-center > p > a#myLearningFromDefault |
Try Frontend Editor (HTML/CSS/JS) div#main > div.ws-black > div.w3-content > a.ws-btn |
Learn More div#main > div.w3-center > div > a.ws-btn |
Learn More div.w3-row > div#main > div.pro-caption > a#proFromDefault |
Learn More div.pro-caption > div.w3-content > div.w3-col > a.w3-button |
Exercises div.w3-row-padding > div.w3-half > p > a.w3-button |
Get started div#main > div#getdiploma > div > a.w3-btn |
These are opportunities to improve the legibility of your content.
Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
With the world's largest web developer site. div#main > div.ws-black > div.w3-content > h3.learntocodeh3 |
HTML Example: div.w3-content > div.w3-col > div.w3-hide-small > h3 |
CSS Example: div.w3-content > div.w3-col > div.w3-hide-small > h3 |
JavaScript Example: div.w3-content > div.w3-col > div.w3-hide-small > h3 |
Python Example: div.w3-content > div.w3-col > div.w3-hide-small > h3 |
SQL Example: div.w3-content > div.w3-col > div.w3-hide-small > h3 |
A web server programming language div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
A JS library for developing web pages div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
A programming language div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
A programming language div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
A CSS framework for faster and better responsive web pages div.w3-col > div.w3-card-2 > div > h5 |
A CSS framework for designing better web pages div.w3-col > div.w3-card-2 > div > h5.w3-text-dark-grey |
Create an account to track your progress, get your own website,
and get access … div#main > div.w3-row > div.w3-center > h4 |
With our online code editor, you can edit code and view the result in your brow… div#main > div.ws-black > div.w3-content > h4.w3-center |
If you want to create your own website, check out W3Schools Spaces. div#main > div.w3-center > div > h3 |
No installation required - just open your browser and start coding: div#main > div.w3-center > div > h5 |
And unlock powerful features: div.w3-row > div#main > div.pro-caption > h3 |
W3Schools' famous color picker: div#main > div.w3-center > div.w3-content > h4 |
Test your skills! div.w3-row > div#main > div.w3-center > h4 |
Browse our selection of free responsive HTML Templates div.w3-row > div#main > div.w3-center > h4 |
Code snippets for HTML, CSS and JavaScript div.w3-row > div#main > div#howto_padding > h4.xxw3-text-dark-grey |
For example, how to create a slideshow: div.w3-row > div#main > div#howto_padding > h6 |
These are opportunities to improve keyboard navigation in your application.
Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. Learn more about touch targets.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
HTML Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
CSS Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
JavaScript Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
How To Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
SQL Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Python Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
W3.CSS Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Bootstrap Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
PHP Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Java Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
C++ Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
jQuery Tutorial div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
HTML Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
CSS Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
JavaScript Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
SQL Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Python Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
W3.CSS Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Bootstrap Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
PHP Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
HTML Colors div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Java Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
AngularJS Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
jQuery Reference div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
HTML Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
CSS Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
JavaScript Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
How To Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
SQL Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Python Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
W3.CSS Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Bootstrap Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
PHP Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Java Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
XML Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
jQuery Examples div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
HTML Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
CSS Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
JavaScript Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Front End Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
SQL Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Python Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
PHP Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
jQuery Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
Java Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
C++ Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
C# Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
XML Certificate div#spacemyfooter > div > div.footerlinks_2 > a.ga-bottom |
These items highlight common accessibility best practices.
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.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Get Certified div#top-nav-bar > div#pagetop > div.tnb-right-section > a.user-anonymous |
Upgrade div#top-nav-bar > div#pagetop > div.tnb-right-section > a.user-anonymous |
Teachers div#top-nav-bar > div#pagetop > div.tnb-right-section > a.user-anonymous |
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.
Descriptive link text helps search engines understand your content. Learn how to make links more accessible.
Performance issues directly impact user engagement and conversion rates.
| Link destination | Link Text |
|---|---|
| www.w3schools.com/go/go_exercises.php | Go |
| www.w3schools.com/go/index.php | GO |
| www.w3schools.com/go/index.php | Go |
| www.w3schools.com/spaces/index.php | Learn More |
| order.w3schools.com/plans | Learn More |
| www.w3schools.com/academy/index.php | Learn More |
Format your HTML in a way that enables crawlers to better understand your app’s content.
Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable
Performance issues directly impact user engagement and conversion rates.
| Uncrawlable Link |
|---|
div#subtopnav > div#menubtn_container > span > a.topnav-icons div#subtopnav > div#menubtn_container > span > a.topnav-icons |
body.w3s-user-anonymous > div.topnavcontainer > div#subtopnav > a body.w3s-user-anonymous > div.topnavcontainer > div#subtopnav > a |
CONTACT US div#spacemyfooter > div > div.footerlinks_1 > a |
cookies div#footerwrapper > div#spacemyfooter > div.footertext > a.ga-bottom |
To appear in search results, crawlers need access to your app.
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