Core Web Vitals measure real-user experience: loading, interactivity, and visual stability. They are not the only ranking factor, but they correlate with engagement—and frustrated users leave.
Largest Contentful Paint (LCP)
LCP marks when the main content becomes visible. Fix it by optimizing the hero image or video poster, using a CDN, and avoiding massive above-the-fold carousels. Preload critical fonts and consider modern image formats.
Interaction to Next Paint (INP)
INP replaces FID for responsiveness. Heavy third-party scripts—chat widgets, trackers, A/B tools—often hurt INP. Load them after interaction or on idle. Break up long JavaScript tasks.
Cumulative Layout Shift (CLS)
CLS happens when elements jump as resources load. Set width and height on images and embeds. Avoid injecting banners above existing content without reserving space.
Measurement
Use Search Console's Core Web Vitals report plus lab tools like Lighthouse. Fix URL templates that affect many pages first—template wins scale better than one-off tweaks.