How to Measure Core Web Vitals

· Category: Web Performance

Short answer

Core Web Vitals can be measured using lab tools like Lighthouse and field tools like the Chrome User Experience Report. Both approaches are necessary for a complete picture.

Steps

  1. Run Lighthouse in Chrome DevTools for lab data on your local machine.
  2. Use PageSpeed Insights to see both lab and real-user field data.
  3. Add the web-vitals JavaScript library to capture metrics in production.
  4. Review the Chrome UX Report in Search Console for origin-level trends.
  5. Set up Real User Monitoring with tools like New Relic or Datadog.

Tips

  • Field data reflects real network conditions; lab data is reproducible.
  • Focus on the 75th percentile of users, not averages.
  • Measure on real devices, not just emulators.

Common issues

  • Local tests on fast machines may not represent mobile user experiences.
  • Ad blockers and extensions can skew lab measurements.