Core Web Vitals Monitoring
Track real user performance metrics with Google Chrome UX Report data
What are Core Web Vitals?
Core Web Vitals are Google's metrics for measuring real user experience. We track these metrics using Chrome User Experience Report (CrUX) data, which reflects actual performance experienced by real Chrome users visiting your pages.
Metrics Tracked
LCP - Largest Contentful Paint
Measures loading performance. Good: < 2.5s, Needs Improvement: 2.5s-4s, Poor: > 4s
INP - Interaction to Next Paint
Measures interactivity. Good: < 200ms, Needs Improvement: 200ms-500ms, Poor: > 500ms
CLS - Cumulative Layout Shift
Measures visual stability. Good: < 0.1, Needs Improvement: 0.1-0.25, Poor: > 0.25
FCP - First Contentful Paint
Measures perceived load speed. Good: < 1.8s
TTFB - Time to First Byte
Measures server responsiveness. Good: < 800ms
Custom Threshold Alerts
Configure custom thresholds for each metric and device type (phone/desktop). Get alerts when:
- P75 value exceeds your threshold
- Week-over-week regression detected
- Month-over-month regression detected
- "Good" proportion drops below threshold
Historical Data
Track trends over time with up to 25 weeks of historical CrUX data. Visualize performance changes and identify patterns.
