100% Free · No login required

Core Web Vitals Checker

Analyze your page experience in minutes. Measure LCP, INP, and CLS, identify render-blocking resources, and fix speed bottlenecks to drive more organic traffic.

Instant results No data stored Powered by AI

Analyzing 25,000+ Performance Tests Every Month

Join thousands of developers and SEOs optimizing their page speed for better rankings.

12M+

URLs Tested

Every 24 Hours

500K+

Audits Run

Per Month

195

Enterprise Sites

Optimized

99 %

CrUX Match

Data Accuracy

Make smarter decisions

Stop Losing Rankings to Slow Pages

Stop guessing why your site failed the Page Experience update. Our tool analyzes your site's performance bottlenecks to prevent slow load times and layout shifts from ruining your user experience.

Identify exactly which element is triggering a high LCP
Pinpoint DOM nodes causing Cumulative Layout Shifts
Debug heavy JavaScript execution hurting your INP score
Compare Lab data with real-world CrUX field data

Check Web Vitals

Features

Complete Web Performance Suite

Everything you need to measure, debug, and optimize your page experience

LCP Optimizer

Analyze your rendering path and identify the exact hero element slowing down your Largest Contentful Paint.

INP Debugger

Find heavy JavaScript execution and long main-thread tasks that delay your Interaction to Next Paint.

CLS Visualizer

Highlight elements that shift during page load to fix visual instability and improve Cumulative Layout Shift.

CrUX Data Fetcher

Extract real-world user experience data from the Chrome User Experience Report directly for your URLs.

Lighthouse Auditor

Run simulated mobile and desktop performance tests in a controlled environment to benchmark improvements.

Waterfall Analyzer

Visualize your asset loading sequence to spot third-party scripts blocking your main thread.

Mobile Simulator

Test your page speed over simulated 3G and 4G connections to ensure performance for all users.

Performance Reports

Export branded PDF reports outlining Core Web Vitals optimization opportunities for your clients.

How it works

Measure Web Vitals in 3 Steps

The fast way to ensure your pages deliver a top-tier user experience

1

Enter Your URL

Paste the webpage you want to test. Our system will initialize headless browsers to simulate user interactions and load patterns.
2

Analyze Metrics

We compile data on LCP, INP, and CLS, combining simulated lab data with historical 28-day field data from Chrome users.
3

Fix & Optimize

Review the specific DOM elements causing issues, implement structural changes, and watch your Google Page Experience signals turn green.

Why choose

Why Use Our Vitals Checker?

The most comprehensive performance diagnostic tool for professional SEOs

Deep Scan Technology

We don't just give you a number. We analyze your critical request chain and network waterfalls.

CrUX Data Integration

Overlay your lab results with historical field data from actual Chrome users over the last 28 days.

Element Debugging

Locate the exact DOM nodes causing Cumulative Layout Shifts or slowing down Largest Contentful Paint.

Mobile-First Auditing

Simulate performance on low-end mobile devices and slow 4G networks to optimize for everyone.

Branded PDF Reports

Generate white-label performance audits for your clients with actionable fix recommendations.

Continuous Monitoring

Check your vitals daily and get alerted if a new deployment breaks your page experience score.

Who it's for

Who Needs Core Web Vitals Optimization?

Performance matters for every type of website

E-Commerce Platforms

Every millisecond counts. Improve your LCP to reduce bounce rates and increase checkout conversions.

Faster product page loads
Reduced layout shifts
Higher conversion rates

Publishers & Bloggers

Keep your readers engaged by ensuring your content stays stable and becomes interactive instantly.

Improved scroll stability
Instant ad rendering
Higher dwell time

Agencies & Freelancers

Deliver massive value to your clients by proving your optimizations with branded performance audits.

Client-ready PDF reports
Comparative benchmarks
ROI demonstration

SaaS & Tech Teams

Monitor your web app's responsiveness and interactivity to provide a premium software experience.

INP monitoring
JS execution profiling
Performance regression checks

Testimonials

Trusted by Performance Experts

See how top engineering teams are passing the Page Experience assessment

FAQ

Frequently Asked Questions

Everything you need to know about Google's Page Experience metrics

What is Largest Contentful Paint (LCP)?

LCP measures loading performance. To provide a good user experience, LCP should occur within 2.5 seconds of when the page first starts loading. Common causes of poor LCP include slow server response times, render-blocking JS/CSS, and slow resource load times.

How is Interaction to Next Paint (INP) different from FID?

While First Input Delay (FID) only measured the first interaction, INP measures all interactions on a page. It provides a more comprehensive score of a page's responsiveness. A good INP score is 200 milliseconds or less.

What causes high Cumulative Layout Shift (CLS)?

CLS measures visual stability. It's often caused by images without dimensions, ads/embeds without reserved space, or dynamic content injected from the top. A good CLS score is 0.1 or less.

What is the difference between Lab and Field data?

Lab data is collected in a controlled environment (like Lighthouse), whereas Field data (CrUX) is collected from real users in the real world over time. Field data is what Google actually uses for ranking.

How often should I check my Web Vitals?

You should check your vitals after every major code deployment, design change, or third-party script addition. Regular monitoring helps prevent performance regressions that could hurt your SEO.

Does passing Core Web Vitals guarantee a ranking boost?

While Web Vitals are a confirmed ranking factor, they are one of many. However, passing the Page Experience assessment acts as a "tie-breaker" for similar content and significantly improves user engagement metrics.

Ready to Identify & Fix Your Performance Issues?

Join 25,000+ engineers optimizing their Core Web Vitals today.

Get Started Free