Session Duration
The total amount of time a user spends on a website during a single visit or session.
Definition
Session duration (also called "time on site") measures how long visitors spend on your website during a single session. It's calculated from the timestamp of the first page view to the last interaction, though the time spent on the final page is often not captured unless an event fires.
Longer session duration generally indicates engaging content and effective user experience, though interpretation varies by site type. A quick-answer reference site might succeed with short sessions, while an e-commerce site wants extended browsing.
Why It Matters
Session duration indicates content engagement and site value. Users who spend more time typically view more pages, consume more content, and are more likely to convert. It's a quality signal that complements traffic quantity metrics.
For content sites, session duration directly impacts advertising revenue. For lead generation and e-commerce, longer sessions correlate with higher conversion rates as users explore and build confidence.
Examples in Practice
A content team tracks session duration by article topic, discovering which subjects drive deeper engagement and deserve more investment.
An e-commerce site's session duration increases 40% after adding related product recommendations, correlating with higher average order value.
A SaaS company finds users with 5+ minute sessions convert at 3x the rate of those under 2 minutes, informing retargeting strategy.