Unique visitors, users and sessions: why the numbers can differ
Unique visitors, or users, count the different people a tool recognised in a date range. Sessions count visits. One person can be one user and five sessions, and two tools can look at the same site and disagree on both.
TL;DR
- Unique visitors (Google Analytics calls them users) are the browsers or devices a tool recognised, each counted once in the date range.
- Sessions are visits. One person who comes back after a gap adds a session, not a visitor.
- Two tools disagree because each recognises visitors and ends sessions in its own way.
Stickybeak shows visitors and sessions for every site you own on one live wall. It is in early access. Free up to 10k pageviews a month, then $20 a month for Solo.
Get early accessWhat do visitors, users and sessions each count?
Three words get used for three different things. Keep them apart and most of the confusion goes.
| Word | What it counts | One person who comes back |
|---|---|---|
| Unique visitors (or users) | Different browsers or devices the tool recognised, each counted once in the date range | Still 1 |
| Sessions (or visits) | Periods of activity. A new one starts after the old one has ended | 1 more each time they return after a gap |
| Page views | Every page loaded, including repeats | 1 more for every page |
Google Analytics 4 uses the word users. Its help page on user metrics defines total users as "the number of unique users who triggered any event in the specified date range" and active users as "the number of unique users who engaged with your site or app in the specified date range". Both counts apply to the date range you choose.
Google defines a session in its own help page as "a period of time during which a user interacts with your website or app". Unless you change it, GA4 ends a session after 30 minutes of inactivity. Other tools choose their own rule, so the sessions figure changes between tools too.
A worked example: one person, four visits
These are made-up visits, to show where the counts come from. Sam looks at your site four times in a week. Assume a tool that recognises a visitor by a cookie in the browser and ends a session after 30 minutes of inactivity.
| When | Device | What Sam does | Counts as |
|---|---|---|---|
| Monday 9:00 | Phone | Reads three pages over ten minutes | Session 1 |
| Monday 9:20 | Phone | Comes back after 10 minutes and reads two more | Still session 1, because 10 minutes is under the 30-minute limit |
| Monday 19:00 | Phone | Reads one page | Session 2 |
| Wednesday 13:00 | Work laptop | Reads two pages | Session 3 |
Add it up for the week: 3 sessions, 8 page views and 2 unique visitors. Sam is one person, but the phone and the laptop are two browsers with two cookies, so a cookie-based tool counts two visitors. If Sam had logged in on both and your tool counted logged-in people, it would be one.
Now change one detail: Sam reads on the phone on Wednesday too. Monday shows 1 visitor, Wednesday shows 1 visitor, and the two days add up to 2. But the week has only 1 visitor, because it is the same phone. That's why daily unique visitors can add up to more than the weekly figure: a unique count belongs to one date range, and a repeat visitor is counted again in every new range.
Why two tools can show different numbers
Even with the same site and the same week, these differences stack up:
- How a visitor is recognised. A cookie, a login, a device ID or a guess from the browser all give different counts. Clearing cookies turns one person into two visitors.
- What ends a session. A 30-minute gap is Google's default. A tool that ends sessions at midnight, or after a different gap, reports other session counts for the same visits.
- Which visits arrive at all. A script that an ad blocker stops, or that a visitor declines through a consent banner, never reports the visit. Two tools with different scripts miss different visits. Our guide on how to check website traffic covers the ways to cross-check.
- Bots. Some tools filter known crawlers and some don't. See AI crawlers and what they do for what they request, and note that crawlers that never run JavaScript are invisible to script-based analytics.
- The date range and the time zone. A visit at 11pm in one zone is tomorrow in another.
- Active against total. Within GA4, active users and total users are different metrics with different definitions, as quoted above.
So compare a tool with itself, week against week, rather than against another tool. The same goes for bounce rate, which also changes definition from tool to tool.
How Stickybeak counts visitors and sessions
Stickybeak is live analytics for every site you own, and it's in early access. It sets one first-party cookie for the visitor and one for the session, on your own domain, so nobody is counted twice. Nothing is shared with anyone. Bots are labelled and kept out of the visitor numbers, and you can exclude your own visits.
It keeps a month of raw visits so unique counts and filters are exact, with daily totals for everything older. So a unique count over the last month comes from the visits themselves, not from adding up days. A session ends after 30 inactive minutes, as the FAQ explains.
Stickybeak doesn't have a public price yet. If you'd like to try it when there's a spot, leave your email.
Questions
What is a unique visitor?
One browser or device that a tool recognised, counted once in the date range you are looking at. Tools that say "unique visitors" and tools that say "users" mean much the same thing, but each recognises people in its own way, so the totals differ.
What is the difference between users and sessions?
A user is a who and a session is a visit. One user can have many sessions. In Google Analytics 4 a session is a period of time during which a user interacts with your website or app, and by default it times out after 30 minutes of inactivity.
Why are my users fewer than my sessions?
Because people come back. Every return visit after the session has timed out is a new session, but the same person is still one user in the date range.
Is a unique visitor the same as a person?
No. A tool counts what it can recognise, usually a browser or device. One person on a phone and a laptop looks like two visitors, and two people sharing one browser look like one.
Why can daily unique visitors add up to more than the weekly figure?
Because a unique count is for the date range you pick. Someone who visits on Monday and again on Tuesday is one visitor on each day but still only one visitor for the week, so adding the daily figures counts them twice. If nobody comes back on another day, the daily figures do add up to the weekly one.
Sources, checked 16 October 2026: Google Analytics Help, Understand user metrics (total, active and new users) and About Analytics sessions (session definition and the 30-minute default timeout). The example is made up. Stickybeak's cookie and retention details are from our own home page.