⚡ Website Speed Test
Full Lighthouse scores and Core Web Vitals for any page, mobile and desktop.
What this test measures
This tool runs Google's Lighthouse against any page, the same engine behind PageSpeed Insights, and distils the full report into the numbers that decide whether a site feels fast: the overall performance score, the six core timing metrics, and the five biggest fixes ranked by the time they would save. Mobile is the default view because that is how most visitors arrive and how Google judges your site for search.
The metrics, in plain English
- Largest Contentful Paint: how long until the main content appears. Under 2.5 seconds is good.
- Cumulative Layout Shift: how much the page jumps around while loading. Under 0.1 is good, and it is the one users feel as pure annoyance.
- Total Blocking Time: how long scripts freeze the page so taps and clicks do nothing. Under 200 milliseconds is good.
- First Contentful Paint, Speed Index, Time to Interactive: first sign of life, how quickly the visible page fills in, and when the page is fully usable.
Frequently asked questions
Why does my score change between runs?
Lighthouse tests in a lab environment, and real conditions vary: server load, network timing, third-party scripts behaving differently. A swing of a few points is noise. Test two or three times, and worry about the pattern (a metric that is always red) rather than a single score.
What is a good score?
90 and above is genuinely fast. 50 to 89 is the crowded middle where most real sites live and where the listed opportunities pay off fastest. Under 50 usually means one or two heavy problems, often oversized images or too much JavaScript, rather than a generally slow site.
Why is mobile so much slower than desktop?
Lighthouse simulates a mid-range phone on a throttled connection, because that is the honest worst case. Your desktop on office Wi-Fi hides problems your visitors on phones and 4G feel in full.
Where should I start fixing?
With the opportunities list, top first: it is already sorted by estimated saving. Compressing and resizing images plus removing unused scripts account for most recoverable seconds on most sites.