Core Web Vitals — Google's page experience metrics

Google's measures of page experience: loading speed, responsiveness and visual stability.

What it means

Core Web Vitals are measurements Google uses to judge how good a page feels to use: how fast the main content loads, how quickly the page responds to taps and clicks, and whether things jump around.

They are part of Google's wider idea of "page experience".

How it works

There are currently three Core Web Vitals, each with a "good" threshold published by Google:

LCP (Largest Contentful Paint) measures loading. It is the time taken for the biggest image or text block to appear. Good is 2.5 seconds or less.
INP (Interaction to Next Paint) measures responsiveness, meaning how quickly the page reacts after a tap, click or key press. Good is 200 milliseconds or less. INP replaced an older metric called FID in March 2024.
CLS (Cumulative Layout Shift) measures visual stability, meaning how much content moves unexpectedly. Good is 0.1 or less.

You can test any page in PageSpeed Insights, and see how your whole site is doing in the Core Web Vitals report in Google Search Console.

A simple example

A saree shop in Surat notices mobile visitors leaving its product pages quickly. PageSpeed Insights shows a poor LCP because the main photo is a huge, uncompressed file. It also shows layout shift because a banner loads late and pushes the "Buy Now" button down.

The developer compresses the images and reserves space for the banner. Pages now load faster and stay steady.

Why it matters

Google uses page experience signals in ranking, although great content still matters most. More importantly, a fast, stable page keeps visitors happy, which can improve engagement and conversions.

Beginner tips

Check your key pages in PageSpeed Insights, especially the mobile results.
Compress images and avoid oversized files.
Set fixed sizes for images, ads and banners so content does not jump.
Common mistake: chasing a perfect score instead of fixing what real users experience.