Core Web Vitals explained
LCP, INP and CLS – what's behind Google's three metrics and how to improve them.
Mira Schulz · Development
1 min read
Contents
Google rates the user experience of a website with three metrics, the Core Web Vitals. They sound technical, but they describe everyday experiences.
LCP: How fast does the content appear?
Largest Contentful Paint measures when the largest visible element has loaded – usually an image or a heading. Good is under 2.5 seconds. What helps: small images in modern formats and a fast server.
INP: How fast does the page respond?
Interaction to Next Paint measures how long the page takes to visibly respond after a click or key press. Good is under 200 milliseconds. The biggest enemy: too much JavaScript.
CLS: Does anything jump around?
Cumulative Layout Shift measures how much content moves while loading – for example when an image loads late and pushes the text down. Good is a score under 0.1. The fix: reserve space for images and ads in advance.
How to measure it yourself
- PageSpeed Insights shows real user data and lab results.
- Lighthouse in Chrome DevTools checks individual pages.
- Search Console lists issues across your whole website.
Our websites reach the green range for all three metrics – we check that before every launch.
