Core Web Vitals
Google's metrics for measuring user experience: loading, interactivity, and visual stability.
What is Core Web Vitals?
Core Web Vitals are a set of specific metrics that Google considers important for user experience. They measure three aspects of page experience: loading performance (LCP), interactivity (INP), and visual stability (CLS).
As of 2024, these are confirmed ranking factors. Google uses field data from real users (Chrome User Experience Report) to evaluate Core Web Vitals, not just lab tests.
Why Core Web Vitals matters
Core Web Vitals are direct ranking factors. Pages that pass Core Web Vitals thresholds may rank higher than slower competitors, all else being equal. Beyond SEO, better performance improves user experience, reduces bounce rates, and increases conversions.
How to implement
Measure current scores with PageSpeed Insights
Prioritize fixes based on impact
Optimize LCP: reduce server time, optimize images, preload critical resources
Optimize INP: reduce JavaScript, break up long tasks
Optimize CLS: set image dimensions, avoid inserting content above existing content
Monitor field data in Search Console
Common mistakes to avoid
- Only checking lab data, ignoring field data
- Optimizing for desktop when mobile is the issue
- Making changes that hurt one metric while improving another
- Not testing on actual devices and connections
Examples
LCP: Hero image loads in 1.8 seconds (Good)
INP: Button click responds in 150ms (Good)
CLS: No layout shifts, score of 0.05 (Good)
Frequently asked questions
Good: LCP < 2.5s, INP < 200ms, CLS < 0.1. Needs Improvement: LCP 2.5-4s, INP 200-500ms, CLS 0.1-0.25. Poor: anything above.
They're a tiebreaker. Content relevance still dominates, but among equally relevant pages, better Core Web Vitals can provide an edge.