Website speed test
Core Web Vitals for your homepage, and the weight, caching and image problems that slow down every other page.
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- 138 checks
- 500 pages free
Website speed test: what’s checked
Most speed tests measure one URL. That tells you how your homepage loads, but not whether the product template ships a 3 MB hero image or the blog serves uncompressed HTML — problems that repeat on every page built from the same template.
This test does both. Your homepage gets a full Lighthouse run on a simulated mobile connection: LCP, CLS, Total Blocking Time, render-blocking files and third-party scripts. Then the crawl checks every page it reaches for oversized HTML, missing compression and cache headers, heavy images and too many script and style files.
21 Speed & performance Slow pages lose visitors and rank worse on mobile. These checks cover load timings, server response and the page weight behind them.
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Deep critical request chain
Long chains of dependent requests delay rendering. Reduce nesting and preload key resources.
Measured on your homepage with Google PageSpeed Insights.
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Excessive DOM size
A very large DOM slows rendering and JavaScript. Simplify page structure and paginate or lazy-load long lists.
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HTML not compressed
Uncompressed HTML wastes bandwidth and slows loads. Enable gzip or Brotli compression on your server.
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Heavy main-thread work
Too much main-thread work makes pages feel sluggish. Minimize JS, simplify styles, and offload work.
Measured on your homepage with Google PageSpeed Insights.
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Heavy third-party scripts
Third-party scripts (analytics, chat, ads) can dominate load time. Audit and defer or remove non-essential ones.
Measured on your homepage with Google PageSpeed Insights.
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High Cumulative Layout Shift (CLS)
Cumulative Layout Shift measures unexpected movement as the page loads. Set width/height on images and reserve space for ads/embeds.
Measured on your homepage with Google PageSpeed Insights.
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High JavaScript bootup time
Heavy JavaScript execution delays interactivity. Reduce, split, or defer scripts.
Measured on your homepage with Google PageSpeed Insights.
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High Total Blocking Time (TBT)
Total Blocking Time reflects how long the page is unresponsive to input. Break up long JavaScript tasks and defer non-critical scripts.
Measured on your homepage with Google PageSpeed Insights.
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Large HTML payload
Oversized HTML delays first render, especially on mobile. Trim inline data, whitespace and unused markup.
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Large total page weight
Heavy pages are slow and costly on mobile data. Compress images, scripts and fonts to cut total weight.
Measured on your homepage with Google PageSpeed Insights.
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Legacy HTTP/1.x in use
HTTP/1.x is slower than HTTP/2/3, which load many resources in parallel. Enable HTTP/2 on your server or CDN.
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Low Lighthouse Performance score
A low Lighthouse Performance score signals slow real-world loads. Work through the LCP/CLS/TBT items to improve it.
Measured on your homepage with Google PageSpeed Insights.
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No CDN detected
A CDN serves assets from locations near your visitors, cutting latency. Consider putting static assets behind a CDN.
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No IPv6 (AAAA) DNS record
Without an IPv6 (AAAA) record, IPv6-only clients can’t reach you directly. Add AAAA DNS records if your host supports it.
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No cache headers
Without cache headers, browsers re-download assets on every visit. Set Cache-Control/Expires on static resources.
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Render-blocking resources
CSS/JS in the <head> delays first paint. Defer or async non-critical resources and inline only what’s needed above the fold.
Measured on your homepage with Google PageSpeed Insights.
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Slow First Contentful Paint (FCP)
First Contentful Paint is when the first content appears. Reduce render-blocking CSS/JS and speed up the server to improve it.
Measured on your homepage with Google PageSpeed Insights.
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Slow Largest Contentful Paint (LCP)
Largest Contentful Paint measures how fast the main content appears; slow LCP hurts rankings and UX. Optimize your largest image/text block and server response.
Measured on your homepage with Google PageSpeed Insights.
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Slow server response (TTFB)
A slow Time To First Byte delays everything else. Improve hosting, caching, or database performance.
Measured on your homepage with Google PageSpeed Insights.
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Too many script or stylesheet files
Each script and stylesheet is a file the browser has to fetch, parse and run before the page settles. A page pulling dozens of them is usually carrying a plugin per feature; bundle what belongs together and drop what the page never uses.
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Web fonts missing font-display:swap
Without font-display:swap, text can be invisible while web fonts load. Add font-display:swap to your @font-face rules.
Measured on your homepage with Google PageSpeed Insights.
9 Images Images are usually the heaviest thing on a page and the easiest to get wrong. These checks cover alt text, dimensions, modern formats and lazy loading.
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Below-fold images load eagerly
Eagerly loading off-screen images wastes bandwidth and slows first paint. Add loading="lazy" to below-the-fold images.
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Images displayed stretched or squashed
An image drawn at the wrong aspect ratio looks distorted. Match the width and height attributes or CSS to the file’s proportions, or use object-fit.
Measured on your homepage with Google PageSpeed Insights.
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Images missing alt text
Alt text describes images to screen-reader users and to search engines (helping image search). Add concise, descriptive alt text; leave it empty only for decorative images.
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Images missing width/height
Images without width/height cause layout shift as they load. Set explicit dimensions or aspect-ratio.
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Images too low-resolution for the screen
An image with fewer pixels than its display size times the screen density looks soft on phones and retina displays. Serve a larger version through srcset.
Measured on your homepage with Google PageSpeed Insights.
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Images use legacy formats (jpg/png)
Modern formats like WebP/AVIF are far smaller than JPG/PNG. Serve next-gen formats to speed up loads.
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Images without srcset
Serving one large image to every device wastes mobile bandwidth. Provide srcset/sizes so browsers pick the right size.
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Inefficient animated GIFs
Animated GIFs are huge; video is far smaller. Replace them with MP4/WebM video.
Measured on your homepage with Google PageSpeed Insights.
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Large image files
Heavy images slow every page that uses them, and a large hero image is often what decides the page’s Largest Contentful Paint. Resize to the size it is displayed at, compress it, and serve WebP or AVIF.
9 JavaScript & CSS Script and stylesheet files are downloaded and parsed before a page can finish rendering. These checks find the ones that are unnecessary, unminified or broken.
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Deprecated browser APIs in use
Deprecated APIs keep working until the browser removes them, and then the feature built on them breaks without warning. Update the script or library that calls them.
Measured on your homepage with Google PageSpeed Insights.
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Errors in the browser console
Console errors usually mean a script failed — a broken widget, a blocked request, a missing file. If the failing script renders content or links, Google may not see them either. Open the page with the browser console open and fix what it reports.
Measured on your homepage with Google PageSpeed Insights.
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Heavy inline CSS
Large blocks of inline CSS can’t be cached and bloat every page. Move styles into external, cacheable stylesheets.
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Heavy inline JavaScript
Large inline scripts block rendering and can’t be cached. Move JavaScript to external, deferred files.
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Images, scripts or stylesheets that fail to load
The page asks for these files and the server does not deliver them. A missing image leaves a visible hole; a missing stylesheet or script can leave the page unstyled or half-working, and a crawler that cannot fetch your CSS judges the layout on markup alone. Fix the path or remove the reference.
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Legacy / over-transpiled JavaScript
Shipping transpiled ES5 to modern browsers wastes bytes. Serve modern JavaScript to capable browsers.
Measured on your homepage with Google PageSpeed Insights.
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Unminified CSS
Unminified CSS ships extra bytes. Minify stylesheets in your build.
Measured on your homepage with Google PageSpeed Insights.
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Unminified JavaScript
Unminified JavaScript ships extra bytes and slows parsing. Minify scripts in your build.
Measured on your homepage with Google PageSpeed Insights.
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Unused CSS rules
Unused CSS forces browsers to download and parse styles that never apply. Remove dead CSS or split it per template.
Measured on your homepage with Google PageSpeed Insights.
How it works
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1
Enter your URL
Paste your homepage. No account, no install, no verification.
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We crawl your site
The crawler follows your internal links and runs every check against each page it reaches.
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Get your results
See your score and issue counts at once. A free account shows every finding, page by page, with how to fix it.
Frequently asked questions
Which pages get Core Web Vitals?
Your homepage, measured with Google PageSpeed Insights on a mobile profile. The site-wide checks — page size, compression, caching, images — run on every page the crawl reaches.
Are these real-user numbers?
No, they are lab measurements from a Lighthouse run, which are repeatable and good for spotting what to fix. If you connect Search Console you also see how your pages perform in search.
Does a faster site rank better?
Core Web Vitals are one of Google’s page experience signals. They rarely outrank relevance, but a slow page loses visitors before they read anything, which matters regardless of rankings.
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