HTML & CSS · Senior · Question 20 of 75
How does lab data (Lighthouse) differ from field data (CrUX, RUM)?
- ✓Correct answer: Lab is a controlled measurement; field data comes from real users
- 2Lab data is more accurate and matches field data when configured correctly
- 3Field data is collected only for mobile devices on 4G
Explanation
Lab data is reproducible and handy for debugging but doesn't reflect the real variety of devices, networks and scenarios. Field data (Chrome UX Report, your own RUM via web-vitals) shows what users actually experience, and Google assesses Core Web Vitals from it. INP can't even be measured in the lab without real interactions.