✳ Website speed test

Website speed test: see why your page is slow and what to fix first.

A slow page loses visitors before they read a word. WebCheck measures how fast your page loads on mobile and desktop and tells you, in plain language, which changes will help most.

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What the speed test measures

WebCheck runs a Lighthouse lab test and reports the key loading metrics:

First Contentful Paint: when the first text or image appears.
Largest Contentful Paint: when the main content is visible (a Core Web Vital).
Total Blocking Time: how long scripts keep the page from responding.
Cumulative Layout Shift: how much the layout moves while loading (a Core Web Vital).
Speed Index: how quickly the page looks complete.

The most common causes of a slow website

Images that are too large or not in a modern format (WebP, AVIF).
Render-blocking CSS and JavaScript in the page head.
Slow server response or chains of redirects.
Third-party scripts: chat widgets, ads, trackers.
Missing browser caching for static files.

For each problem found, WebCheck shows the estimated savings and a concrete fix, so you can start with the changes that matter.

Mobile vs desktop speed

Mobile tests simulate a mid-range phone on a slower network, so scores are usually lower than on desktop. Google mostly uses the mobile version of your site, so start there. Choose “Both” to test mobile and desktop in one go.

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Frequently asked questions

Why does my speed score change between two tests?

Lab tests depend on network conditions and server load at that moment. Small variations are normal; compare trends rather than single runs.

Is this the same as Google PageSpeed Insights?

WebCheck uses the same Lighthouse engine through the PageSpeed Insights API, then adds priorities, explanations and a client-ready report.

What is a good page speed score?

Lighthouse considers 90–100 good, 50–89 needs improvement and below 50 poor. Focus first on Largest Contentful Paint and layout shifts.

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Updated 22 October 2026