Google Analytics 4 · Metric
What is Average session duration?
Average session duration is the mean length of a session in Google Analytics 4: the total duration of all sessions divided by the number of sessions, in seconds. A session lasts from its first event to its last.
Total session time divided by sessions: the average visit.
- Data source
- Google Analytics 4
- Type
- Metric
- API field
- averageSessionDuration
- Formula
- Average session duration = total session duration / sessions
Why it matters
In Universal Analytics the last page of a visit counted as zero seconds, which made single-page visits look instant. GA4 measures engagement time between events instead, so the same behaviour now produces a longer and more truthful number.
How to read it
The distribution is heavily skewed: most sessions are short and a few are very long, so the average is pulled up by the tail. There is no universal "good" value; a support article and a product catalogue should differ. Compare it against your own previous period and read it next to engagement rate, which is far less sensitive to outliers.
In a Data Studio report
In a Data Studio (formerly Looker Studio) report it is a scorecard on the engagement page, with its change against the previous period, and a breakdown by channel or landing page to see which entry points keep people and which lose them.
Where to find it in Google Analytics 4
Google Analytics 4: Reports, then Engagement, then Overview; add Average session duration as a column in any report under Customize report.
