Guide
Glossary
Core Web Vitals
Core Web Vitals are three measurements Google uses to judge how a web page feels to real visitors: Largest Contentful Paint (LCP) for loading, Interaction to Next Paint (INP) for responsiveness, and Cumulative Layout Shift (CLS) for visual stability. A page meets the "good" thresholds when, at the 75th percentile of visits, LCP is 2.5 seconds or less, INP is 200 milliseconds or less and CLS is 0.1 or less. INP replaced First Input Delay in March 2024. The scores come from real Chrome users' visits. Google says good scores align with what its ranking systems reward, but they do not make up for content that fails to answer the searcher's question.
Also called CWV, LCP, INP and CLS
Last updated:
Example
In an accounting firm
For example, an accounting firm's home page loads a large uncompressed photo and a chat widget before its text, and mobile LCP is about 4 seconds. Serving the photo as AVIF or WebP at the right size, with its width and height set, and loading the widget after the page is the kind of fix that brings LCP under 2.5 seconds and stops the layout jumping.
How do you check a website’s Core Web Vitals?
Run the page through PageSpeed Insights, which shows real-visitor data from the previous 28 days alongside a Lighthouse lab test. Google Search Console’s Core Web Vitals report groups a verified site’s pages as good, needing improvement or poor. If a site does not get enough Chrome traffic for real-visitor data, lab tests become the main guide. Because field data covers 28 days, a fix can take up to four weeks to show in it.
Guides that explain it in context
Secure by design. Set up correctly. Fully managed.
Talk to us before you commit to anything
Start with a free 45-minute discovery call. We look at your systems and priorities, then recommend a first step with a fixed scope, or tell you if we are not the right fit.