# Core Web Vitals

> Core Web Vitals are three user-experience metrics, LCP, INP and CLS, assessed on real-user data at the 75th percentile.

**Core Web Vitals** are three metrics Google uses to describe the experience of loading and using a page:

| Metric | Measures | Good |
|---|---|---|
| [LCP](/glossary/lcp) | Loading | 2.5 s or less |
| [INP](/glossary/inp) | Responsiveness | 200 ms or less |
| [CLS](/glossary/cls) | Visual stability | 0.1 or less |

A page **passes** when all three are good at the 75th percentile of real-user visits, as measured in the [Chrome UX Report](/glossary/crux). INP replaced First Input Delay in March 2024.

Lighthouse measures LCP and CLS in the lab, and uses [Total Blocking Time](/glossary/tbt) as a lab proxy for responsiveness. Use lab results to find and fix problems, and field data to confirm that real visitors see the improvement.