Core Web Vitals Checker
Check real-user LCP, INP and CLS from the Chrome UX Report for a page and its whole site.
About the Core Web Vitals Checker
Core Web Vitals are the three user-experience metrics Google uses as part of its page experience signals:
- Largest Contentful Paint (LCP) – how quickly the main content appears. Good: 2.5 seconds or less.
- Interaction to Next Paint (INP) – how quickly the page responds when people tap, click or type. Good: 200 ms or less. INP replaced First Input Delay in March 2024.
- Cumulative Layout Shift (CLS) – how much the layout jumps around while loading. Good: 0.1 or less.
A page passes when the 75th percentile of real visits is “good” for all three. This checker reads that field data from the Chrome UX Report (the data Google uses) for both the URL and the whole site, over the last 28 days.
Frequently asked questions
What is the difference between field and lab data?
Field data comes from real Chrome users over 28 days and is what Google uses. Lab data (Lighthouse) is a simulated test – useful for debugging, but it cannot measure INP directly.
How long until improvements show up?
Field data is a rolling 28-day window, so fixes take up to four weeks to be fully reflected.
Are Core Web Vitals a big ranking factor?
They are one of many signals. Relevance and content quality matter far more, but between similar pages a better experience can tip the balance – and it always helps conversions.