Enter a page URL to see real-user field data collected from Chrome users and, where available, lab measurements, shown separately. LCP, INP and CLS are rated good, needs improvement or poor.
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Core Web Vitals measure user experience from three angles. The thresholds below are the ones published on web.dev:
| Metric | What it measures | Good | Needs improvement | Poor |
|---|---|---|---|---|
| LCP (Largest Contentful Paint) | How quickly the main content appears | ≤ 2.5 s | 2.5–4 s | > 4 s |
| INP (Interaction to Next Paint) | How quickly the page responds to clicks, taps and key presses | ≤ 200 ms | 200–500 ms | > 500 ms |
| CLS (Cumulative Layout Shift) | How much content moves around while loading | ≤ 0.1 | 0.1–0.25 | > 0.25 |
According to web.dev, a page passes when these targets are met at the 75th percentile of page loads. So even if most visits are fine, a slow quarter of visits can push the result to "needs improvement".
Field data tells you what happens; lab data helps explain why. Real users arrive on all sorts of devices and connections, and field data reflects what they actually experience. A lab run is one controlled test, and its numbers can differ from field data. When the two disagree, trust the field data for user experience.
INP can't be measured directly in the lab. It requires real interactions. Lab tools run without a user clicking around, so they typically show indirect indicators, such as long tasks blocking the main thread, instead.
Common causes:
To watch field data for your whole site every day, alongside a weekly technical crawl, see the SEO site audit.
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Field data comes from the real experiences of Chrome users who visited the page and summarises the last 28 days. Lab data is a single test in a controlled environment with an assumed device and connection. They answer different questions, which is why they're shown separately.
The Chrome UX Report only publishes data for pages and origins with enough real-user experiences. Low-traffic pages may have none; in that case the tool says so rather than estimating. When page-level data is missing, origin-level data can still give you a sense of the site as a whole.
Google's documentation says good Core Web Vitals, together with other aspects of page experience, align with what its core ranking systems seek to reward. The same documentation says Google still tries to show the most relevant content even when page experience is weaker, and that good scores don't guarantee top rankings. The clearest benefit is a better experience for the people using the page.
Field data covers a rolling 28-day window, so improvements show up gradually and can take about four weeks to be fully reflected. Lab measurements reflect the change immediately.
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