Core Web Vitals: The Complete 2026 Guide

Core Web Vitals have been a confirmed Google ranking factor since 2021. In 2026, they remain critical — especially as mobile traffic continues to dominate. Here is everything you need to know.

The Three Metrics

Largest Contentful Paint (LCP) measures loading performance. Target: under 2.5 seconds. Common fixes: optimise images (WebP format, lazy loading), upgrade server response time, eliminate render-blocking resources.

Cumulative Layout Shift (CLS) measures visual stability. Target: under 0.1. Common causes: images without dimensions, dynamically injected content above the fold, web fonts causing FOUT.

Interaction to Next Paint (INP) replaced FID in 2024. Measures responsiveness. Target: under 200ms. Common fixes: break up long JavaScript tasks, defer non-critical JS.

Tools for Measurement

SeoCute Site Audit measures CWV for all your key pages and tracks them over time. Google Search Console CWV report shows field data (real users). PageSpeed Insights shows lab data for individual URLs.