Session

Updated 2026-11-02

Definition

A session is one visit to your site. It starts when someone arrives and ends after a period of inactivity, commonly 30 minutes. One person can have many sessions, and one session can include many pageviews.

Sessions sit between visitors and pageviews. Visitors tell you how many browsers came. Sessions tell you how often they came. Pageviews tell you how much they looked at.

Example

This example uses made-up numbers. Jo visits your site at 9:00 and views three pages by 9:10. Jo goes to a meeting, comes back at 9:25, and views one more page. That's still one session, because the gap was under 30 minutes.

Jo returns at 2:00 in the afternoon and views two pages. That's a second session.

So for the day, Jo counts as 1 visitor, 2 sessions and 6 pageviews.

Across your whole site, 8,000 visitors with 11,000 sessions works out to about 1.4 sessions per visitor.

Why sessions differ between tools

Tools make different choices. Some start a new session at midnight, or when a visitor arrives from a new campaign. Others don't. So two tools on the same site won't show the same number. Pick one source for trends and compare it to itself over time.

How Headstream measures it

A new Headstream session starts after 30 minutes without activity. The script stores a session ID in the browser's session storage and refreshes its timer with each event. Session storage belongs to a browser tab, so a visitor working in two separate tabs can produce two sessions.

Sessions matter beyond traffic reports. In Headstream, each session counts as one touchpoint for attribution, classified by its first pageview. A session count is labeled an estimate. Bots and excluded traffic are left out. The methodology page has the full definition.