By SitemapFixer Team
Updated April 2026

Core Web Vitals: LCP, INP, and CLS Explained

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Core Web Vitals are real-world performance metrics Google uses as ranking signals. They measure loading speed, interactivity, and visual stability. Pages that pass the thresholds receive a ranking boost.

LCP - Largest Contentful Paint

Good: Under 2.5sNeeds work: 2.5s-4.0sPoor: Over 4.0s

LCP measures how long the largest visible element (usually a hero image or headline) takes to load. Improve it by optimizing images, using a CDN, preloading critical resources, and eliminating render-blocking scripts.

INP - Interaction to Next Paint

Good: Under 200msNeeds work: 200ms-500msPoor: Over 500ms

INP replaced FID in March 2024. It measures interaction latency throughout a page visit. Improve it by minimizing JavaScript execution, breaking up long tasks, and deferring non-critical scripts.

CLS - Cumulative Layout Shift

Good: Under 0.1Needs work: 0.1-0.25Poor: Over 0.25

CLS measures visual stability - unexpected layout shifts during loading. Fix it by setting width and height on images, reserving space for ads, and using font-display: optional for web fonts.

How to Check Your Scores

Check scores in Google Search Console under Experience then Core Web Vitals. For page-level data use PageSpeed Insights. For immediate testing use Lighthouse in Chrome DevTools. Note: Search Console shows 28-day field data - changes take time to appear.

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