User metrics
In plain English: A user is GA4's measured identity—not a guaranteed unique human.
Total users counts unique users who triggered any event in the period. Active users is GA4's primary user metric in reports and reflects users who met its activity conditions. New users triggered first_visit or first_open in the period.
Cookies, consent, device changes, User-ID choices and reporting thresholds can split or combine identities.
- One person on a phone and laptop may appear as two users.
- A returning visitor who clears identifiers may appear new again.
Sessions
In plain English: A session is a period of activity, not a person.
A session begins when a page or screen is viewed and no session is active. A later visit can start another session for the same user.
- Alex visits Monday and Friday: one measured user may have two sessions.
- Ten users can produce more than ten sessions.
Engaged sessions
In plain English: GA4 classifies a session as engaged when it crosses at least one defined threshold.
An engaged session lasts longer than 10 seconds, has a key event, or includes at least two page or screen views. This is a classification rule, not proof that a visitor was satisfied.
Keep in mind: The condition is longer than 10 seconds—not simply 10 seconds.
Choose the right count
In plain English: Use users for audience reach and sessions for visits or opportunities to interact.
Compare both with context. A documentation site may want returning users and engaged reading sessions; a support page might solve a problem in one short session.