Real-User Field Data
Results come from Chrome UX Report — real user metrics, not synthetic lab tests — so you see actual performance.
Core Web Vitals Checker for LCP, INP, and CLS
TL;DR: Core Web Vitals Checker helps you fetch real-user CrUX metrics for LCP, INP, and CLS.. Run the check instantly, review prioritized findings, and apply fixes that improve crawl quality, answer extractability, and AI citation readiness without any signup barrier.
Use real-world Chrome UX data to prioritize performance fixes.
Updated April 12, 2026
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LCP measurement INP measurement CLS measurement Mobile vs. desktop split
What is Core Web Vitals Checker?
This checker uses Google Chrome UX Report data to return p75 values and distribution bands for key performance metrics. It highlights whether your origin passes Core Web Vitals on mobile and desktop.
Why it matters for SEO: Core Web Vitals (LCP, INP, CLS) are confirmed Google ranking signals. Pages that fail these thresholds lose competitive advantage, especially in mobile search where performance matters most.
Performance Monitoring: Check whether recent code changes or third-party scripts have degraded real-user performance before rankings are affected.
Mobile vs Desktop Comparison: Identify if your site passes on desktop but fails on mobile — a common pattern that can hurt mobile-first indexing outcomes.
Client Reporting: Pull CrUX field data to show clients the real-world impact of performance optimizations you have recommended or implemented.
How to Use This Tool
- 1 Enter a URL or origin.
- 2 Choose mobile or desktop form factor.
- 3 Inspect LCP, INP, CLS values and thresholds.
- 4 Prioritize optimizations for failed metrics.
What You Get
Pass/Fail by Device
Check whether your origin passes Core Web Vitals thresholds on mobile and desktop independently.
Metric Distribution Bands
See p75 values and good/needs-improvement/poor distribution for each metric to target precise optimizations.
Frequently Asked Questions
Answers about Core Web Vitals Checker
You can check Core Web Vitals by entering any URL or origin into the checker. It returns field performance data for LCP, INP, and CLS with pass or fail status broken down by mobile and desktop device types.
Google's recommended thresholds are LCP at or under 2.5 seconds, INP at or under 200 milliseconds, and CLS at or under 0.1. These are measured at the 75th percentile of real user experiences from Chrome UX Report data.
Yes, this Core Web Vitals Checker uses real user data from the Chrome UX Report (CrUX). Results reflect actual field performance from real visitors rather than controlled lab simulations, making them more representative of ranking signals.
Yes, Core Web Vitals are part of Google's page experience ranking signals. While not the only factor, poor LCP, INP, or CLS scores can weaken your competitive position against pages with better performance metrics.