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Web Vitals Guide

Master Core Web Vitals with the Web Vitals Guide. Look up LCP, INP and CLS thresholds, then grade your own scores.

Core Web Vitals reference

Official thresholds, then grade your own numbers below.

Grade your scores

Enter lab or field measurements.

Good to know: Google grades real-user (field) data at the 75th percentile. Lab numbers are useful for debugging but the field verdict is what counts.
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What the vitals measure

LCP times the largest visible element, INP measures responsiveness to interaction, and CLS scores visual stability. Together they are Google's Core Web Vitals, the page-experience signals used in ranking. FCP and TTFB are supporting diagnostics.

How grading works here

Enter your measured values and each is graded against the official thresholds: green is good, amber needs improvement, red is poor. Remember Google judges the 75th percentile of real users, so one good lab run does not guarantee a passing field score.

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Web Vitals Guide FAQs

Where do I get my real numbers?
PageSpeed Insights and Search Console show field data for your URLs; Lighthouse gives lab numbers for debugging.
Why did INP replace FID?
First Input Delay only measured the first interaction's delay. INP measures responsiveness across the whole visit, which reflects real experience better.
What is a good CLS score?
0.1 or less. Layout shifts frustrate users most when they cause misclicks, so keep it green.
Do vitals affect SEO?
They are a ranking signal among many. Good vitals rarely rank a page alone, but poor ones can hold a page back.
Are these thresholds current?
Thresholds shown match Google's published guidance. If Google updates them, the cards here may lag; check web.dev for the latest.
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