# Unique visitor

> A browser or person counted once in a period, however many times they visited.

Source: https://datacenter.so/glossary/unique-visitor
Also called: unique user, users, visitors.

Unique visitors (or users) count people, approximately. Cookie-based tools recognize a returning browser by an id in a cookie. Cookieless tools use a daily hash, so the same person on two days counts once per day.

Neither recognizes one person across a phone and a laptop without a login, and clearing cookies or declining consent makes a returning person look new. GA4 shows several user metrics; most reports use Active users ([Google](https://support.google.com/analytics/answer/12253918)).

## Related terms

- https://datacenter.so/glossary/session
- https://datacenter.so/glossary/pageview
- https://datacenter.so/glossary/cookieless-tracking