What are Core Web Vitals?
Core Web Vitals are Google's three page experience metrics: LCP for loading, INP for responsiveness and CLS for visual stability, with their thresholds.
Updated
Core Web Vitals are three metrics Google uses to measure real users’ experience of a page: how fast the main content loads, how quickly the page responds to input, and how stable the layout is. A page passes when all three are “good” for at least 75% of visits.
What are the three Core Web Vitals?
| Metric | Measures | Good | Poor |
|---|---|---|---|
| Largest Contentful Paint (LCP) | Loading | 2.5 s or less | Over 4 s |
| Interaction to Next Paint (INP) | Responsiveness | 200 ms or less | Over 500 ms |
| Cumulative Layout Shift (CLS) | Visual stability | 0.1 or less | Over 0.25 |
Values in between are “needs improvement”. INP replaced First Input Delay (FID) as a Core Web Vital in March 2024.
Where does the data come from?
From real Chrome users, through the Chrome User Experience Report (CrUX). Search Console’s Core Web Vitals report and the field data in PageSpeed Insights both use it. Lab tools such as Lighthouse simulate a load and help you debug, but they are not what Google assesses. Pages without enough traffic have no field data of their own.
How much do Core Web Vitals affect rankings?
Google uses them as part of its page experience signals, but says relevance and content quality come first: good scores do not guarantee top rankings, and a highly relevant page can rank well despite average scores. Treat them as a tiebreaker and a user experience issue, not a shortcut.
Example
A product page whose hero image loads in 3.4 seconds for the slowest quarter of visitors fails LCP even if it loads in 1.5 seconds on your office Wi-Fi. Compressing and preloading that image usually fixes it.