The three metrics#
| Metric | Measures | Good | Poor |
|---|---|---|---|
| LCP — Largest Contentful Paint | When the main content finishes rendering | ≤ 2.5 s | > 4 s |
| INP — Interaction to Next Paint | Responsiveness to clicks, taps and typing | ≤ 200 ms | > 500 ms |
| CLS — Cumulative Layout Shift | Unexpected movement of content | ≤ 0.1 | > 0.25 |
INP replaced First Input Delay (FID) as a Core Web Vital in March 2024. A page passes when at least 75% of real visits meet the “good” threshold for each metric.
Field data vs lab data#
Field data comes from real Chrome users (the Chrome UX Report) and is what Google uses. Lab data (Lighthouse) is a simulated test useful for debugging. Your Lighthouse score is not your Core Web Vitals result.
Why they matter#
- They’re part of Google’s page experience signals — a modest ranking consideration, most useful as a tie-breaker.
- They strongly correlate with user satisfaction, bounce and conversion.
Where to check#
- Search Console → Core Web Vitals (groups of URLs, mobile and desktop).
- PageSpeed Insights (field data for a URL or origin, plus lab diagnostics).
- Chrome DevTools Performance panel for detailed debugging.
For fixes, read Core Web Vitals on WordPress. Related: technical SEO checklist.