Definition
What is Session?
A session is a group of user interactions with your website that take place within a given time frame. In GA4, a session begins when a user first interacts with a page (triggering a session_start event) and ends after 30 minutes of inactivity or at midnight. A single user can generate multiple sessions across different visits.
Why it matters
Sessions are the foundational unit for engagement and conversion analysis, and understanding session boundaries is critical for interpreting GA4 reports accurately.