Unique visitors
Unique visitors counts distinct people (or devices) visiting a site over a period, as opposed to pageviews, which counts every page load — the same visitor loading ten pages is one unique visitor and ten pageviews.
Analytics and the web
Cookie-based analytics tools count uniqueness by reading back a persistent visitor ID: if the same cookie value shows up twice, it is the same visitor. That approach is precise when the cookie survives, but it fails silently whenever it doesn’t — private browsing, cookie clearing, cross-device visits, or consent rejection all inflate the unique count by turning one real person into several apparent ones.
Cookieless tools cannot read back a stored ID, so they estimate uniqueness from request-level signals over a bounded window instead of maintaining a durable per-visitor profile. This trades some precision for not requiring any persistent identifier on the visitor’s device — the count is an aggregate estimate, not a guarantee that no two counted visits came from the same person.
Pulse Analytics reports unique visitor counts with a salted visitor hash that resets on the site’s identity window, a calendar month by default, so a returning reader counts once within the window. It avoids cookies and fingerprinting, and nothing links a reader across sites or across windows.