Free Core Web Vitals Checker

Use real-world Chrome UX data to prioritize performance fixes.

Example result — enter a URL to run your own
Core Web Vitals Assessmentwarn

Fails Core Web Vitals for mobile users.

LCP (p75)pass

1850ms • Good 72% | Needs improvement 20% | Poor 8%

INP (p75)pass

145ms • Good 81% | Needs improvement 14% | Poor 5%

CLS (p75)pass

0.050 • Good 89% | Needs improvement 8% | Poor 3%

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. 1 Enter a URL or origin.
  2. 2 Choose mobile or desktop form factor.
  3. 3 Inspect LCP, INP, CLS values and thresholds.
  4. 4 Prioritize optimizations for failed metrics.

What You Get

Real-User Field Data

Results come from Chrome UX Report — real user metrics, not synthetic lab tests — so you see actual performance.

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