The three metrics
- LCP (Largest Contentful Paint): how long the largest visible element takes to appear. Target: under 2.5 seconds.
- INP (Interaction to Next Paint): the delay after a click or keystroke. Target: under 200 milliseconds.
- CLS (Cumulative Layout Shift): unexpected layout movement. Target: under 0.1.
- These thresholds are explained on web.dev (opens in a new tab), Google’s reference site.
Why it matters
Google includes these metrics in its page experience assessment (opens in a new tab). But the main issue is commercial: a slow site loses visitors before they read your offer.
A fast site is also crawled more efficiently, including by AI search crawlers, which supports your GEO.
The levers that matter most
- Images in AVIF or WebP, at the right size.
- Fonts hosted on your own server and preloaded.
- As few third-party scripts as possible, loaded after the page renders.
- Reserved space for every image and block, to prevent layout shifts.
Measure before you act
Test your site with PageSpeed Insights (opens in a new tab). This site scores 100 on all four categories: see the details on our Custom websites page, along with our commitment to at least 90/100 for every site we deliver.