Definition
Core Web Vitals (CWV) are Google's three field-measured user-experience metrics: Largest Contentful Paint (LCP, loading speed), Interaction to Next Paint (INP, interactivity), and Cumulative Layout Shift (CLS, visual stability). Originally a ranking signal for SEO, they're now a strong eligibility filter for AI Overview citations. Slow or jumpy pages are systematically excluded.
Good thresholds: LCP < 2.5s, INP < 200ms, CLS < 0.1. Measured in Chrome User Experience Report (CrUX) data.
How to optimize
Optimize LCP via image preloading + CDN. Fix INP by reducing JS execution time. Lock CLS by reserving image dimensions + avoiding late-loaded content above the fold.
