SEO glossary · Updated
Core Web Vitals: LCP, INP and CLS, explained
Core Web Vitals are three metrics for real-world page experience: Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness) and Cumulative Layout Shift (visual stability).
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Core Web Vitals are three measurements of how a page feels to real users: how fast the main content appears, how quickly the page responds when someone taps or clicks, and whether the layout jumps around while it loads.
| Metric | Measures | Good |
|---|---|---|
| Largest Contentful Paint (LCP) | When the largest image or text block becomes visible | 2.5 seconds or less |
| Interaction to Next Paint (INP) | How quickly the page responds to interactions | 200 milliseconds or less |
| Cumulative Layout Shift (CLS) | How much content moves unexpectedly | 0.1 or less |
A page meets the threshold when at least 75% of visits are in the good range. INP replaced First Input Delay (FID) as a Core Web Vital in March 2024.
Do Core Web Vitals affect rankings?
Google says Core Web Vitals are used by its ranking systems, and recommends good scores, but that good page experience doesn't override relevance: a slow page with the best answer can still outrank a fast one with a poor answer. Treat them as a tie-breaker and a user-experience fix, not a shortcut.
Where to measure them
- Search Console's Core Web Vitals report: field data from real Chrome users, grouped by page type.
- PageSpeed Insights: field data for a URL plus a Lighthouse lab test with suggestions.
- Chrome DevTools: for debugging on your own machine.
Common fixes
| Metric | Usual causes | Fixes |
|---|---|---|
| LCP | Slow server, large hero image, render-blocking CSS and JS | Faster hosting or caching, compressed and properly sized images, preload the hero image |
| INP | Heavy JavaScript on the main thread | Less and later JavaScript, break up long tasks |
| CLS | Images and ads without dimensions, late-loading fonts and banners | Set width and height, reserve space for ads and embeds |
Check it on your own site
What the free audit tests for this
- Load time
- Image formats
- Lazy loading
One URL, about 20 seconds, no login. You get the result of every check and the exact fix for the top three issues.
Audit your website freeFAQ
What is a good LCP score?+
2.5 seconds or less, for at least 75% of page visits.
What is CLS in SEO?+
Cumulative Layout Shift: a measure of how much a page's content moves around unexpectedly while it loads. 0.1 or less is good.
Do Core Web Vitals matter for a small site?+
They matter for your visitors on any site. For rankings they're one signal among many; relevance and content quality come first.
Sources
- Understanding Core Web Vitals and Google search results — Google Search Central
- Web Vitals — web.dev