Performance · Website glossary

Field data

Quick answer · What is Field data?

Performance measurements collected from real visits in actual user environments.

IN PRACTICE

Field data: an example

A report combines measurements from visitors with different phones, networks, and interaction patterns.

KEEP IN MIND

A field dataset has coverage and aggregation limits; missing data is not proof a page is fast.

Put the idea to work

Frequently asked questions

What is a practical example of Field data?

A report combines measurements from visitors with different phones, networks, and interaction patterns.

Does missing field data prove a page is fast?

A field dataset has coverage and aggregation limits; missing data is not proof a page is fast.

Which concepts should I read alongside Field data?

Lab data: Measurements collected in a controlled or simulated test environment.
Core Web Vitals: A set of user-experience metrics covering loading, interaction responsiveness, and visual stability, currently LCP, INP, and CLS.