How it's measured
Analytics SDKs start a session when the app comes to the foreground and end it after the app has been in the background for a timeout (often 30 seconds to a few minutes). Average session length = total session time ÷ number of sessions.
How to read it
Longer isn't always better:
- For a game or reading app, longer sessions usually mean more engagement.
- For a banking or utility app, short sessions can mean the app does its job quickly.
Look at session length together with sessions per user and DAU/MAU — frequency often matters more than duration.
Example
A recipe app sees average session length fall from 6 to 4 minutes after a redesign, while sessions per user rise. Reviews say "much faster to find a recipe now" — the shorter sessions are a good sign. Reading app reviews next to metrics helps interpret changes like this.