Core Web Vitals: what actually moves the needle

Largest Contentful Paint

LCP is usually the hero image or the headline. Compress and serve the hero in a modern format at the size it is displayed, preload it, and stop lazy-loading the image that sits above the fold. Those three changes fix most slow LCP scores.

Fonts come second. Self-host them, subset them, and use font-display swap so text appears before the font file finishes downloading.

Cumulative Layout Shift

Layout shift is almost always an image or embed without reserved space. Set explicit width and height on every image and aspect ratio on every video container. Reserve space for banners and cookie notices before they render.

Interaction to Next Paint

INP punishes long JavaScript tasks. Audit third-party scripts first: chat widgets, heatmaps and tag managers frequently account for more main-thread work than the application itself. Load them after interaction or remove the ones nobody uses.

Then split large bundles so the first page does not ship code for screens the visitor may never open.