Free · No signup · Real-user field data

Free Core Web Vitals Checker

See the real-user Core Web Vitals for any site from Google's CrUX field data: LCP, INP and CLS at the 75th percentile, mobile and desktop.

Try an example: https://www.google.com
Real-user field data · LCP, INP, CLS · mobile and desktop · one-click monitoring

What this Core Web Vitals checker shows

This tool reads Google's Chrome UX Report (CrUX), the same real-user dataset Google uses for page experience. It returns the 75th-percentile LCP, INP and CLS for the URL you enter, plus FCP and TTFB for context, and tells you whether the page passes Core Web Vitals.

Field data versus lab data

Lab tools run a single synthetic test on demand. Field data is aggregated from real Chrome users over the trailing 28 days, so it reflects the devices, networks and conditions your actual visitors have. CrUX is field data, which is why it can differ from a one-off lab score.

Mobile and desktop, side by side

Google ranks on the mobile experience, so this tool shows mobile and desktop together. A site can pass on desktop and fail on mobile, and that gap is exactly where ranking and conversion are usually lost.

From a one-off check to continuous monitoring

A single check is a snapshot. LoadFocus page-speed monitoring runs scheduled checks from 25+ regions and alerts you when LCP, INP or CLS regress, so you catch a slowdown before your visitors and your rankings do.

Related: Website Speed Test · Page Speed Monitoring · API Status Checker

Frequently asked questions

What are Core Web Vitals?

Core Web Vitals are three real-user metrics Google uses to measure page experience: Largest Contentful Paint (LCP) for loading, Interaction to Next Paint (INP) for responsiveness, and Cumulative Layout Shift (CLS) for visual stability.

Is this real-user (field) data or lab data?

This tool shows field data from the Chrome UX Report, aggregated from real Chrome users over the last 28 days. It is not a single lab run, so it reflects what real visitors actually experience.

Why is there no data for my site?

CrUX only reports sites with enough real Chrome traffic. New or low-traffic pages may have no URL-level or origin-level data yet. For those, run a lab test on our Website Speed Test tool instead.

Do Core Web Vitals affect SEO?

Yes. Core Web Vitals are part of Google's page experience signals and can influence rankings, especially as a tie-breaker between pages of similar relevance. Good vitals also improve conversion and engagement.

What is INP?

Interaction to Next Paint (INP) measures how quickly a page responds to user interactions across the whole visit. It replaced First Input Delay (FID) as a Core Web Vital in 2024, so this tool reports INP, not FID.

Can I monitor Core Web Vitals continuously?

Yes. This free checker is a one-off snapshot. LoadFocus page-speed monitoring runs scheduled checks from 25+ regions and alerts you when your vitals regress.
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