SEO glossary

Core Web Vitals (CWV)

Core Web Vitals are three Google metrics that measure real users' experience of a web page: Largest Contentful Paint (LCP) for loading, Interaction to Next Paint (INP) for responsiveness and Cumulative Layout Shift (CLS) for visual stability. Each is assessed at the 75th percentile of page visits.

Reviewed by Gareth Hoyle, Managing Director
Last reviewed 31 October 2026

What are the Core Web Vitals thresholds?

Google measures each metric at the 75th percentile of page visits, separately for mobile and desktop, so at least three in four visits need to meet the good threshold.

LCP: good at 2.5 seconds or less, poor above 4 seconds
INP: good at 200 milliseconds or less, poor above 500 milliseconds
CLS: good at 0.1 or less, poor above 0.25

When did INP replace FID?

INP replaced First Input Delay (FID) as a Core Web Vital on 12 March 2024. FID only measured the input delay of the first interaction on a page. INP observes all clicks, taps and key presses during a visit, from the input until the browser paints the next frame.

Do Core Web Vitals affect rankings?

Google recommends good Core Web Vitals for success in Search and says they align with what its core ranking systems seek to reward. It also says Search always aims to show the most relevant content, even if the page experience is sub-par. A fast page with a weak answer will not outrank a slower page that answers the query better.

Search Console's Core Web Vitals report uses field data from the Chrome User Experience Report, groups similar URLs and rates each group by its slowest metric. Lab tools such as Lighthouse help diagnose problems but don't show what real visitors experience.

Example

A recipe site's LCP is 4.6 seconds on mobile because the hero photo is a 3MB file set to lazy-load. Compressing the image and loading it straight away brings LCP under 2.5 seconds. Setting width and height on the ad slots stops the method jumping down the page as ads load, which fixes CLS.