Google UX & Core Web Vitals
Test your site for mobile-friendliness and real-user Core Web Vitals (CrUX) using Google's official APIs. Optimize page experience for better rankings and happier users.
About Google UX & Page Experience
Test mobile-friendliness and Core Web Vitals using real user data from Google's Chrome User Experience Report
Google UX helps you measure and optimize your site's user experience with official Google APIs, testing mobile usability and Core Web Vitals performance based on real-world user data.
Mobile-Friendly Test
Check if your page works well on mobile devices with Google's Mobile-Friendly Test API
Core Web Vitals
Measure LCP, INP, and CLS using real user data from Chrome UX Report (CrUX)
Real User Metrics
See actual performance from real Chrome users, not synthetic lab tests
Performance Distribution
View histograms showing how your metrics perform across all users
Pass/Fail Verdicts
Get clear verdicts for each metric against Google's thresholds
Actionable Insights
Understand what's working and what needs improvement with detailed recommendations
Understanding Core Web Vitals
Core Web Vitals are a set of metrics Google uses to measure real-world user experience. They're part of Google's page experience signals and can affect search rankings.
LCP
Largest Contentful Paint
How long it takes for the main content to load
Goal: < 2.5 seconds
INP
Interaction to Next Paint
How quickly the page responds to user interactions
Goal: < 200 milliseconds
CLS
Cumulative Layout Shift
How much the page layout shifts unexpectedly
Goal: < 0.1
Why Page Experience Matters
Impact on Rankings
- Direct ranking factor: Page experience is part of Google's ranking algorithm
- Mobile-first: Mobile usability affects how Google indexes your site
- Competitive advantage: Better UX can help you outrank competitors with similar content
Impact on Users
- Lower bounce rates: Fast pages keep visitors engaged
- Higher conversions: Better UX leads to more sales and signups
- Improved satisfaction: Users prefer fast, stable, responsive sites
Mobile-Friendly Test
With over 60% of searches happening on mobile devices, mobile-friendliness is critical for success.
What the test checks:
- Viewport configuration: Proper mobile viewport meta tag
- Text readability: Font size readable without zooming
- Tap target size: Buttons and links large enough to tap
- Content width: No horizontal scrolling required
- Resource loading: All mobile resources accessible
- Compatibility: Works across different screen sizes
Chrome User Experience Report (CrUX)
A public dataset of real user experience data from millions of Chrome users who have opted in to syncing their browsing history and usage statistics.
Shows actual performance for real users on real devices and networks, not synthetic lab conditions. This is the data Google uses for rankings.
Understanding Performance Thresholds
| Metric | Good | Needs Improvement | Poor |
|---|---|---|---|
| LCP | ≤ 2.5s | 2.5s - 4.0s | > 4.0s |
| INP | ≤ 200ms | 200ms - 500ms | > 500ms |
| CLS | ≤ 0.1 | 0.1 - 0.25 | > 0.25 |
Common Issues & Quick Fixes
- Optimize and compress images (use WebP format)
- Enable lazy loading for below-the-fold images
- Minimize render-blocking JavaScript and CSS
- Use a CDN for faster content delivery
- Improve server response time (TTFB)
- Minimize main thread work and long JavaScript tasks
- Break up long tasks into smaller chunks
- Optimize event handlers (debounce/throttle)
- Reduce JavaScript execution time
- Use web workers for heavy computations
- Set explicit width and height for images and videos
- Reserve space for ads and embeds
- Avoid inserting content above existing content
- Use CSS aspect ratio boxes
- Preload custom fonts to prevent FOIT/FOUT
Who Should Use Google UX Tools
Developers
Optimize performance and fix UX issues
Marketers
Improve rankings and conversions
Site Owners
Monitor user experience quality
UX Designers
Validate design decisions with data
Ready to Test Your Page Experience?
Check your mobile-friendliness and Core Web Vitals above