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Core Web Vitals
Google's three page-experience metrics: LCP for loading, INP for interactivity, and CLS for visual stability. What each one measures and why it matters.
What it is
Core Web Vitals are three metrics Google uses to measure how a real page feels to a real visitor. Each one captures a different moment of the experience:
- LCP (Largest Contentful Paint) — loading. How long until the biggest thing on screen (usually the hero image or headline) has rendered. Good is under 2.5 seconds.
- INP (Interaction to Next Paint) — interactivity. How quickly the page visibly responds when someone taps or clicks. Good is under 200 milliseconds.
- CLS (Cumulative Layout Shift) — visual stability. How much the layout jumps around as it loads. Good is under 0.1.
The scores come from real Chrome users, not a lab simulation.
Why it matters
A slow, jumpy page costs you visitors before they read a word, and Google folds page experience into how it crawls, indexes, and serves results. The same speed signals carry over to AI answer engines, which also deprioritise pages that load slowly.
Core Web Vitals are not the biggest ranking factor, and great vitals will not rescue thin content. But when two pages are otherwise close, the faster, steadier one tends to win, and the experience is genuinely better for the human on the other end.
For a plain-language breakdown of how to actually fix each one, read Core Web Vitals for non-engineers.
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