What is Core Web Vitals?
Google's three user experience metrics: LCP, INP, and CLS.
Written by DidYouSEO Team·Updated April 2026
Definition
Core Web Vitals are a set of three specific metrics Google uses to measure real-world user experience on a webpage. The three metrics are: Largest Contentful Paint (LCP) - how fast the main content loads, Interaction to Next Paint (INP) - how responsive the page is to user interactions, and Cumulative Layout Shift (CLS) - how much the page layout shifts unexpectedly during load. Google uses these as ranking signals.
Why it matters for SEO
Since 2021, Core Web Vitals have been an official Google ranking factor. Poor scores can directly suppress your rankings even if your content is excellent. LCP above 4 seconds, INP above 500ms, or CLS above 0.25 all indicate a poor user experience - and Google will rank faster, more stable pages above yours. Improving these scores can lift rankings without changing a word of content.
How to check core web vitals
DidYouSEO's Core Web Vitals tool checks your LCP, INP, and CLS scores using real-world Chrome User Experience (CrUX) data. Enter any URL to see your current scores and whether they pass Google's thresholds.
Check it on your site - free
No credit card. No sign-up required for free tools.