Utilities

Core Web Vitals Checker

LCP / INP / CLS

Measure the three metrics Google ranks on

Powered by Google PageSpeed Insights. Analysis may take 15–45 seconds.
Device
Data source

Field data: the 75th percentile of real visits over the last 28 days — the numbers Google actually ranks on. Only available for pages with enough traffic.

Tool features

Comprehensive web performance analysis
4 checks

Core Web Vitals

Measure LCP, INP, and CLS — Google's key ranking signals

Field & Lab Data

Real 28-day visitor data plus a reproducible lab run

Mobile & Desktop

Test performance on both mobile and desktop devices

Named Culprits

The specific elements and resources holding each metric back

What are Core Web Vitals & how they work

Google's three page-experience ranking signals

Core Web Vitals are the three page-experience metrics Google uses as a ranking signal: LCP (how fast the main content loads), INP (how quickly the page responds to input) and CLS (how much the layout shifts while loading).

One PageSpeed run returns two different measurements. Field data is the 75th percentile of real visits over the last 28 days — the numbers Google ranks on, but only available for pages with enough traffic. Lab data is a single throttled load: reproducible and always available, but it cannot measure INP because there are no real interactions.

LCP
Largest Contentful Paint — main content should render within 2.5s.
INP
Interaction to Next Paint — responses should land under 200ms.
CLS
Cumulative Layout Shift — visual movement should stay below 0.1.

How to use this tool

Measure a page's Core Web Vitals in four steps
1
Enter a URL
Type the full page URL, e.g. https://example.com — test the exact page you care about, not just the homepage.
2
Pick a device
Choose Mobile or Desktop — Google ranks primarily on the mobile experience, so start there.
3
Choose a data source
Field data shows what real visitors experienced; lab data always works and names the specific elements holding each metric back.
4
Review and act
Read the three metrics against Google's thresholds, then work through what's holding them back.

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Open Graph Checker
Check Open Graph meta tags and preview how your page looks when shared on Facebook, Twitter, and Google — get a completeness score

Frequently asked questions

Common questions about Core Web Vitals
5 Q&A

Core Web Vitals are three Google metrics — LCP, INP and CLS — that measure loading, interactivity and visual stability. They are part of Google's page-experience ranking signals.

Aim for LCP under 2.5 seconds, INP under 200 milliseconds, and CLS below 0.1. Meeting all three at the 75th percentile of real users is considered passing.

INP measures the delay between a real interaction and the next frame the user sees. A lab run loads the page in a clean profile without tapping anything, so there is nothing to measure. Field data, collected from real sessions, does include INP.

The Chrome UX Report only publishes data for URLs with enough traffic to be anonymous. For quieter pages it may still have an origin-level sample covering the whole site, and failing that only lab data is available.

Lighthouse simulates a slower CPU and network on mobile, so mobile scores are usually lower. Since Google indexes mobile-first, optimise the mobile experience first.