Core Web Vitals sound technical, but they measure three things any visitor notices without knowing the names. Google uses them to help decide who ranks, which makes them worth understanding even if you never touch the code.
The three metrics
- Largest Contentful Paint (LCP): how long until the main content shows up. Aim for under 2.5 seconds.
- Interaction to Next Paint (INP): how quickly the page responds when someone taps or clicks. Aim for under 200 milliseconds.
- Cumulative Layout Shift (CLS): how much the page jumps around while loading. Aim for under 0.1, which in practice means almost none.
Google measures all three at the 75th percentile of real visits, so a page passes only when three quarters of your actual visitors get a good experience, not when it scores well on your laptop. If a guide still lists First Input Delay, it predates March 2024 and is out of date: INP replaced it.
Those numbers mean nothing until you translate them into what a visitor experiences.
- You tap the link and the page is there.
- You tap "book now" and it responds straight away.
- You read the first line and it stays where you put it.
- You tap the link and stare at white for three seconds.
- You tap "book now", nothing happens, so you tap it again.
- An image loads late, the text jumps, and you tap an ad by mistake.
Why they earn their place in ranking
Each one maps to a moment of frustration: waiting for content, tapping something that does not respond, or losing your place because the layout shifted. Google rewards pages that avoid those moments because its users prefer them. So do yours.
