How visitors are counted

How Privatus Analytics counts visitors and visits without cookies: a daily salted key computed in memory, random visit ids, and what that means for accuracy.

# How visitors are counted

> How Privatus Analytics counts visitors and visits without cookies: a daily salted key computed in memory, random visit ids, and what that means for accuracy.

Privatus Analytics counts real visits and daily unique visitors without cookies,
without storing anything on the visitor's device, and with nothing that
persists or links across days.

## The daily visit key

1. Every UTC day we generate a random 256-bit **salt**. It is held only in
   Redis, with an expiry that deletes it 30 minutes after the day ends. It
   is never written to the database.
2. For each hit, `key = HMAC-SHA256(daily_salt, site, IP, User-Agent)`,
   computed in memory during the request. The hostname is added to the
   key when the site's **Multiple domains** setting is **Separate**.
3. The key is looked up in an in-memory store. If it's new, we start a
   visit with a **random id** that is *not* derived from the key. Entries
   expire after 30 minutes of inactivity and never outlive the UTC day.
4. The stored event has the random visit id and flags such as "first visit
   today". The key, the IP and the raw User-Agent are never stored, logged
   or queued.

Once the salt is deleted, nobody (including us) can recompute a key or
link a stored visit to a person or to another day.

There is one counting method for every site. There are no privacy modes
to choose from.

## Visits, visitors and bounces

- **A visit** ends after 30 minutes without a hit, or at midnight UTC,
  whichever comes first. Only a pageview or a custom event starts a visit.
  Engagement pings, Web Vitals and click-map hits join the current visit
  and are dropped when there is none.
- A visit's source, country and device are those of its first hit. Later
  hits don't change them.
- **A visitor** is counted once per site per UTC day, on their first visit
  of the day. The same browser the next day is a new visitor, so a weekly
  total counts "visitor-days".
- **A bounce** is a visit with one pageview, no custom event and less than
  10 seconds of engaged time.

Funnels, journeys, entry and exit pages, and the pages viewed before a
conversion are all built from these visits.

## What this means for accuracy

- Visitors can't be deduplicated across days, by design. Someone who
  visits on Monday and Tuesday counts twice in a weekly total.
- Two people behind the same IP address with the same browser version
  (an office network, for example) can be counted as one visitor.
- A visitor whose IP address changes during the day (switching from Wi-Fi
  to mobile data) can be counted twice.
- A visit that spans midnight UTC is split into two.
- A browser update during the day changes the User-Agent, so the same
  person starts a new visit and counts as a new visitor.
- With **Multiple domains** set to **Combined** (Site settings → General),
  one visit can span the site's domains. With **Separate**, each domain
  starts its own visits and counts its own visitors.

See [why numbers differ from GA4](/docs/metrics/ga4-differences) for how
this compares with cookie-based tools.

## Your privacy policy

The IP address and User-Agent are processed transiently to build the daily
pseudonymous key, which you should mention in your privacy policy (see
[templates](/docs/privacy/policy-templates)).

Markdown으로 보기

Privatus Analytics counts real visits and daily unique visitors without cookies, without storing anything on the visitor's device, and with nothing that persists or links across days.

The daily visit key#

Every UTC day we generate a random 256-bit salt. It is held only in Redis, with an expiry that deletes it 30 minutes after the day ends. It is never written to the database.
For each hit, key = HMAC-SHA256(daily_salt, site, IP, User-Agent), computed in memory during the request. The hostname is added to the key when the site's Multiple domains setting is Separate.
The key is looked up in an in-memory store. If it's new, we start a visit with a random id that is not derived from the key. Entries expire after 30 minutes of inactivity and never outlive the UTC day.
The stored event has the random visit id and flags such as "first visit today". The key, the IP and the raw User-Agent are never stored, logged or queued.

Once the salt is deleted, nobody (including us) can recompute a key or link a stored visit to a person or to another day.

There is one counting method for every site. There are no privacy modes to choose from.

Visits, visitors and bounces#

A visit ends after 30 minutes without a hit, or at midnight UTC, whichever comes first. Only a pageview or a custom event starts a visit. Engagement pings, Web Vitals and click-map hits join the current visit and are dropped when there is none.
A visit's source, country and device are those of its first hit. Later hits don't change them.
A visitor is counted once per site per UTC day, on their first visit of the day. The same browser the next day is a new visitor, so a weekly total counts "visitor-days".
A bounce is a visit with one pageview, no custom event and less than 10 seconds of engaged time.

Funnels, journeys, entry and exit pages, and the pages viewed before a conversion are all built from these visits.

What this means for accuracy#

Visitors can't be deduplicated across days, by design. Someone who visits on Monday and Tuesday counts twice in a weekly total.
Two people behind the same IP address with the same browser version (an office network, for example) can be counted as one visitor.
A visitor whose IP address changes during the day (switching from Wi-Fi to mobile data) can be counted twice.
A visit that spans midnight UTC is split into two.
A browser update during the day changes the User-Agent, so the same person starts a new visit and counts as a new visitor.
With Multiple domains set to Combined (Site settings → General), one visit can span the site's domains. With Separate, each domain starts its own visits and counts its own visitors.

See why numbers differ from GA4 for how this compares with cookie-based tools.

Your privacy policy#

The IP address and User-Agent are processed transiently to build the daily pseudonymous key, which you should mention in your privacy policy (see templates).