> For the complete documentation index, see [llms.txt](https://webstrategies-inc.gitbook.io/ga4-resource-center/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://webstrategies-inc.gitbook.io/ga4-resource-center/ga4-topics/ga4-topics/what-are-the-differences-between-ga3-sessions-and-ga4-sessions.md).

# What are the differences between GA3 Sessions and GA4 Sessions

**FAQ**: What is the difference between GA3 and [GA4](https://www.linkedin.com/feed/hashtag/?keywords=ga4\&highlightedUpdateUrns=urn%3Ali%3Aactivity%3A7020744037301121024) sessions?

1\) In GA3, a session is a group of hits recorded for a user in a given time period. Whereas in GA4, a session is a group of events recorded for a user in a given time period.

2\) Unlike in GA3, the user activity is detected automatically in GA4. This may lead to higher active user counts for GA4.

3\) The duration of a GA3 session is calculated as the time elapsed between the first and last hit in the session. Whereas the duration of a GA4 session is calculated as the time elapsed between the first and last event in the session.

4\) A GA3 session timeout can not be less than 1 minute or greater than 4 hours. Whereas a GA4 session timeout can not be less than 5 minutes or greater than 7 hours and 55 minutes.

5\) Unlike GA3, A GA4 session begins to time out when a website or app is moved to the background.

6\) A GA3 session expires if a user returns to your website via a different campaign source in the middle of the active session. Whereas, the GA4 session does NOT expire if a user returns to your website via a different campaign source in the middle of an active session.

7\) A GA3 session automatically expires at midnight (11:59:59 pm). Whereas a GA4 session does NOT automatically expire at midnight (11:59:59 pm). However, the same GA4 session would now be counted twice, once for each day.

8\) GA3 counts sessions by counting the sessions metric. Whereas GA4 counts sessions by counting session\_start events.

9\) The session count of GA3 and GA4 are unlikely to match as they are calculated and adjusted differently.