The meaning of "unique users" in Mixpanel depends on the time interval you select in your report:
- If you select a daily interval, "unique users" will show the number of distinct users who performed the event on each day—so a user can be counted once per day if they perform the event on multiple days.
- If you select a 30-day (monthly) interval, "unique users" will show the number of distinct users who performed the event at least once during the entire 30-day period—so each user is only counted once in that 30-day window, regardless of how many times they performed the event.
For example, if you are looking at a 30-day period and select "unique users" with a monthly interval, a user who performed the event multiple times in that month will only be counted once. If you use a daily interval, the same user could be counted on multiple days if they performed the event on those days.
This is confirmed in the documentation:
"If the time interval is 'Month': For each month, we will look at the last date in the time frame, and count 30 days back from that. As long as the user watches video once, anytime between Dec 2 to Dec 31, they will be counted as part of the MAU for Dec."
"If the time interval is 'Day': For each day, we will look at the last date in the time frame, and count 30 days back from that. So for Nov 1, we will count the total number of active users from Oct 3 to Nov 1. As long as the user watches video once, anytime between Oct 3 to Nov 1, they will be counted as part of the MAU for Nov 1."
Mixpanel Docs: Insights - Users
So, to summarize:
- Unique users per day: User can be counted once per day.
- Unique users in 30 days: User is counted once in the whole 30-day period.
