Core Web Vitals

Google's set of real-world performance metrics (LCP, CLS, INP) that measure user experience and are used as ranking signals.

Core Web Vitals are a subset of Web Vitals that Google has designated as ranking signals under the Page Experience update. The three metrics are: Largest Contentful Paint (LCP) — loading speed; Cumulative Layout Shift (CLS) — visual stability; and Interaction to Next Paint (INP) — interactivity responsiveness. INP replaced First Input Delay (FID) as a Core Web Vital in March 2024.

Google measures these from real-user data in Chrome via the Chrome User Experience Report (CrUX). This is important: your field data (from real users) is what affects rankings, not your lab data from tools like Lighthouse. A page can pass Lighthouse checks but fail CrUX thresholds if slow users or slow networks drag down the 75th percentile.

Thresholds: LCP ≤2.5s (good), CLS ≤0.1 (good), INP ≤200ms (good). Pages with "good" scores across all three metrics earn the Page Experience signal benefit. While Core Web Vitals are a ranking factor, they are a tiebreaker rather than a dominant signal — content quality and relevance still matter far more.