With the shift from Universal Analytics to Google Analytics 4 (GA4), many familiar metrics changed, including how sessions are measured. While sessions still represent visits to your website, GA4 approaches them in a more flexible, event-based way.
Let’s break down what sessions mean in GA4, how they start, and how they’re different from the old version of Google Analytics.
In GA4, a session represents a group of user interactions that take place on your website or app within a given time frame.
Just like before, a session reflects a single visit to a domain, and that visit can come from:
- A new user
- A returning user
- The same user multiple times
A single user can generate multiple sessions, and sessions can come from the same or different traffic sources.
How GA4 Starts a Session
GA4 uses an event-based model, meaning every interaction is tracked as an event. A session begins when the session_start event is triggered.
A new session starts when:
- A user visits your site for the first time
- A user returns to your site after being inactive
- A user returns via a new campaign source (such as a different UTM parameter)
Example:
A user visits your site from an organic search, browses a page, and leaves. Later, that same user clicks a paid ad and comes back.
Even though it’s the same person, GA4 records two separate sessions because the acquisition source changed.
How Long Do Sessions Last in GA4?
By default, GA4 sessions:
- Expire after 30 minutes of inactivity
- Can be adjusted in your GA4 settings (up to 7 hours 55 minutes)
Unlike Universal Analytics, midnight resets no longer automatically create a new session. This means sessions can continue across days if the user stays active, resulting in more accurate engagement tracking.
Key Differences Between GA4 Sessions and Universal Analytics Sessions
GA4 made important changes to how sessions work:
- Sessions are event-based, not pageview-based
- Sessions do not restart at midnight
- Sessions do not restart when a user changes campaign source mid-session
- Engagement is measured more accurately using engaged sessions instead of bounce rate
These changes help provide a clearer picture of real user behavior.
Sessions vs. Users in GA4
- Users = unique individuals who visit your site
- Sessions = total visits, including repeat visits
If your session count is higher than your user count, it means users are returning, which is typically a positive signal for brand interest and engagement.
Why Sessions Matter in GA4
Sessions help you understand:
- How often users visit your site
- Which channels drive the most traffic
- How users behave during each visit
When combined with metrics like:
- Engaged sessions
- Engagement rate
- Conversions (key events)
Sessions provide valuable insight into traffic quality, not just traffic volume.
While GA4 still uses sessions as a core metric, the way they’re measured is smarter and more flexible than before. By understanding how sessions work in GA4, you’ll be better equipped to interpret your data and make confident marketing decisions.
Need help with GA4? Contact the experts at TryAds!