What are Core Web Vitals?
Answer
Core Web Vitals are a set of real-world, user-centric performance metrics defined by Google that measure a web page's user experience quality. Since 2021, they are a ranking signal in Google Search. The three current Core Web Vitals: LCP (Largest Contentful Paint): measures loading performance — when the largest image or text block is visible. Good: <2.5s. INP (Interaction to Next Paint): measures responsiveness — the slowest interaction (click, tap, key press) during the entire page visit. Replaced FID in March 2024. Good: <200ms. CLS (Cumulative Layout Shift): measures visual stability — how much page content unexpectedly shifts. Good: <0.1. Measure with: Google Search Console, PageSpeed Insights, Chrome DevTools, Chrome UX Report (real user data), Lighthouse (lab data). Core Web Vitals are part of a broader set of Web Vitals that also include TTFB (Time to First Byte) and FCP (First Contentful Paint).