Official Google data, updated weekly
How fast is your website for real Chrome users?
Query 9 months of public Core Web Vitals data captured from your site's Chrome visitors.
Frequently asked questions
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Core Web Vitals are three metrics Google uses to grade the user experience of a page: Largest Contentful Paint (LCP) for loading speed, Interaction to Next Paint (INP) for responsiveness, and Cumulative Layout Shift (CLS) for visual stability. Google recommends good Core Web Vitals for success in Search.
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From Google's Chrome UX Report (CrUX), a public dataset of real visits by Chrome users on desktop and Android who opted in to share usage statistics. It's the same field data that PageSpeed Insights shows. Chrome on iOS doesn't report to CrUX, and neither do Safari, Firefox, or Edge.
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CrUX only publishes sites that get enough Chrome traffic to keep every visitor anonymous, so new and low-traffic sites are left out. Google doesn't publish the cutoff, and you can't submit a site by hand. A site also has to be publicly discoverable, which means its pages return a 200 status and aren't marked noindex.
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It passes when LCP, INP, and CLS are all good at the 75th percentile: LCP at 2.5 seconds or less, INP at 200 milliseconds or less, and CLS at 0.1 or less. Phones and desktops are graded separately, so check both with the device toggle.
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P75 is the 75th percentile: 3 out of 4 visits were at least that fast. Google grades at P75 so that most visits have to hit the target, while a few outliers on slow devices or networks can't sink the score.
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Lighthouse and the top of a PageSpeed Insights report are lab tests: one load of one page on a simulated device. This checker shows field data from real visits on real devices and networks, which is what Google grades. PageSpeed Insights also shows some field data, but only the latest 28 days, while this checker shows weekly history.
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Each data point covers 28 days of visits, so a fix shows up gradually as new visits replace old ones. Expect the full effect about four weeks after you ship.
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This checker looks up the origin of the URL you enter, which combines every page on your site. To see which element slows a single page, run that page through our LCP Lab Check tool. To see field data for every page, you need Real User Monitoring on your own site, which is what RumDash does.
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Yup! There's no sign-up, and you can look up any public website, including your competitors. We don't like your competitors!