Core Web Vitals Test

Enter any domain or page URL above, including a competitor’s. The free report shows whether the site passes Google’s Core Web Vitals assessment, with 75th percentile values for Largest Contentful Paint, Cumulative Layout Shift and Interaction to Next Paint. It also shows how each has changed in recent months, how they differ by device type and country, and Chrome’s ad metrics for sites that run ads.

Every number comes from the Chrome User Experience Report (CrUX), Google’s public dataset of real page loads from opted-in Chrome users. Most figures cover a rolling 28 days and update daily, while country figures come from Google’s monthly release. CrUX covers Chrome on desktop and Android only, so Safari, Firefox and Chrome on iOS are not included.

Google rates each metric at the 75th percentile of visits, with the same thresholds for every site. Largest Contentful Paint is good at 2.5 seconds or less, Interaction to Next Paint at 200 milliseconds or less and Cumulative Layout Shift at 0.1 or less, and a site passes when all three are good. Time to First Byte (good at 800 milliseconds or less) and First Contentful Paint (good at 1.8 seconds or less) are also graded but do not count towards the assessment.

A site fails when any one of Largest Contentful Paint, Interaction to Next Paint or Cumulative Layout Shift is not good at the 75th percentile, so one slow metric fails the whole assessment even when the other two pass. Find the metric rated needs improvement or poor, and check phones and desktop separately, as Google assesses them separately. Because CrUX covers a rolling 28 days, a fix can take up to four weeks to turn a fail into a pass.

CrUX only publishes data for sites and pages with enough Chrome visits to meet Google’s eligibility thresholds. If an exact URL shows nothing, try the whole domain, as many more sites have domain level data. If the domain has none either, Real User Monitoring measures your own visitors directly, without relying on CrUX.

PageSpeed Insights shows the same CrUX field data, above a Lighthouse lab test of one page load. This report adds weekly history and a breakdown by country, but runs no lab test. The CrUX numbers are field data, which is what Google ranks on. A lab test loads the page once on demand, so you can reproduce a slow page and confirm a fix in minutes. The free website speed test runs one from the location and device you choose.

They are one of Google’s ranking signals, measured with the same CrUX data shown here. Relevance comes first, so passing will not lift a weak page above a strong one, but when many pages are similarly helpful a good page experience can help. Slow pages also lose visitors regardless of ranking.

Start with the worst rated metric. For Largest Contentful Paint, speed up server response, shrink images and cut render blocking scripts; for Cumulative Layout Shift, reserve space for images, ads and embeds; for Interaction to Next Paint, break up long JavaScript tasks. Fixes take a few weeks to show here, because CrUX covers a rolling 28 days.