LCP measures how quickly the main content loads; INP measures how fast the page responds to interactions (it replaced First Input Delay in March 2024); CLS measures how much the layout unexpectedly shifts. Each has target thresholds Google considers "good", measured on real users, primarily on mobile.
They're a genuine but modest ranking factor: they rarely outweigh relevance and content, but they act as a tie-breaker and, more importantly, affect conversions and bounce. A fast, stable page keeps users and helps every other SEO effort pay off.
Improving them is technical SEO work: optimise images and fonts, reduce render-blocking scripts, reserve space for media to prevent shifts, and improve server response. Core Web Vitals sit alongside mobile-first indexing as core page-experience foundations.
FAQ
Frequently asked questions
Yes. In March 2024, Interaction to Next Paint (INP) replaced First Input Delay (FID) as the responsiveness metric in Core Web Vitals, because INP measures the full latency of interactions across a page visit, not just the first input.