Core Web Vitals 2026: what they are and how to improve them step by step

Core Web Vitals are three Google metrics that measure the loading speed (LCP), responsiveness (INP) and visual stability (CLS) of a web page. From a minor ranking signal, they have become a basic technical requirement: a slow or unstable site loses positions regardless of the quality of its content.

The three Core Web Vitals metrics explained

Google measures them both in the lab (Lighthouse) and on real user data (CrUX, the Chrome User Experience Report). Only real data counts for ranking.

How to improve Core Web Vitals: practical steps

To improve LCP

Compress and serve images in next-gen formats (WebP, AVIF), enable server-side caching, reduce render-blocking resources (critical CSS and JavaScript) and use a CDN for static assets.

To improve INP

Reduce non-essential JavaScript executed at load, break long scripts into smaller tasks, and avoid heavy libraries when they aren’t needed.

To improve CLS

Always reserve space for images and videos with the width and heightattributes, avoid injecting dynamic content (banners, popups) above content that has already loaded, and preload fonts to avoid the so-called layout shift caused by font swapping.

Why it is no longer optional in 2026

With search increasingly mediated by generative engines and AI Overviews, crawlers favor technically solid pages even more: an unstable site risks not even being considered as a source. A technical SEO audit is the first step to understand where you are losing points.

Frequently asked questions about Core Web Vitals

For the official definition, see the Google Core Web Vitals documentation.