How does this Core Web Vitals checker work?

This tool uses Google PageSpeed Insights API to analyze your page. It measures LCP, CLS, TBT (Total Blocking Time), FCP (First Contentful Paint), and Speed Index, then grades your performance and provides specific optimization recommendations to improve your scores.

How can I improve my Core Web Vitals scores?

Common fixes include optimizing and lazy-loading images to improve LCP, setting explicit width and height on media elements to reduce CLS, minimizing JavaScript execution to lower TBT, and using a CDN for faster asset delivery. Our tool provides specific recommendations tailored to your page.

Free Core Web Vitals Checker

Test LCP, CLS, INP, FCP, and Speed Index using Google PageSpeed Insights data. Free, instant, no signup required.

What This Tool Measures

Seven performance metrics pulled live from Google PageSpeed Insights — the same data Google uses to evaluate your page for ranking.

🔥 Largest Contentful Paint (LCP)

How fast your main content loads. Good: <2.5s · Needs work: 2.5-4s · Poor: >4s

🔄 Cumulative Layout Shift (CLS)

Visual stability — how much content jumps around. Good: <0.1 · Needs work: 0.1-0.25 · Poor: >0.25

⚡ Interaction to Next Paint (INP)

Responsiveness to clicks and taps. Good: <200ms · Needs work: 200-500ms · Poor: >500ms

⏲ First Contentful Paint (FCP)

Time until the first text or image appears on screen. Good: <1.8s · Poor: >3s

🚫 Total Blocking Time (TBT)

Time the main thread is blocked by JavaScript. Good: <200ms · Poor: >600ms

📊 Speed Index

How quickly page content is visually complete. Good: <3.4s · Poor: >5.8s

🎯 Overall Performance Score

Weighted composite (0-100). Good: 90+ · Needs work: 50-89 · Poor: <50. Same score shown in Chrome DevTools.

How to Use This Core Web Vitals Checker

Enter your URL — Type or paste any webpage address into the input field above.

Run the test — Click "Check Vitals" and wait while we analyze your page through Google PageSpeed Insights.

Review your scores — See your LCP, CLS, TBT, FCP, and Speed Index with color-coded pass/fail indicators.

Fix the issues — Follow the optimization tips provided to improve your page speed and user experience.

Why Core Web Vitals Matter for Rankings

Core Web Vitals are a set of real-world performance metrics that Google uses as ranking signals. Since 2021, pages that meet Google's thresholds for LCP, CLS, and interactivity receive a ranking boost in mobile and desktop search results. Poor scores can push your pages below competitors who deliver a faster experience.

Beyond rankings, page speed directly affects conversions. Studies consistently show that each additional second of load time increases bounce rates and reduces revenue. Optimizing your Core Web Vitals improves both search visibility and user experience, making it one of the highest-ROI technical SEO investments you can make.

Frequently Asked Questions

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