Why did my unique users jump in Mixpanel?
The Mixpanel help pages give 4 common reasons. The first to rule out: When one person is given two different user IDs, Mixpanel counts them as two users, even if other details about them match.
What causes it?
When one person is given two different user IDs, Mixpanel counts them as two users, even if other details about them match.
In the Mixpanel help:
If the same user receives two different IDs, Mixpanel treats them as separate users, even if they share other properties.
Identity Management FAQ, read 2026-11-12.With Mixpanel's client-side libraries, a visitor who clears their stored browser data, or a site that calls reset, gets a new ID, so the same visitor can be counted again.
In the Mixpanel help:
If the user clears this data (or you call `reset()`), the SDK generates a new `distinct_id`.
Identity Management FAQ, read 2026-11-12.If your website, app and server each send a different ID for the same person, that person can appear once for each.
In the Mixpanel help:
Web, mobile, and server-side each assigning a different ID produces one profile per platform.
Duplicate or orphaned user profiles, read 2026-11-12.A profile import that uses the wrong column as the user ID can create a new profile for every row, so the user count can jump.
In the Mixpanel help:
Selecting the wrong column as `$distinct_id` during a profile import creates a profile per row.
Duplicate or orphaned user profiles, read 2026-11-12.
How do I check it myself?
Check which identity system the project uses, in its settings, since what can be merged depends on it.
In the Mixpanel help:
Check that first, in project settings.
Duplicate or orphaned user profiles, read 2026-11-12.Check that each person is sent with one ID that never changes, such as a database ID.
In the Mixpanel help:
Pick one stable `$user_id` per user
Duplicate or orphaned user profiles, read 2026-11-12.
How does Mixpanel work with Feder?
- Connect Mixpanel to Feder and it joins your Visits apps.
- When you connect Mixpanel, Feder checks the connection straight away and shows Connected only when that check passes. If a reading cannot be taken later, Feder shows it as not read, never as zero.
Some numbers are too quiet to judge daily, such as a form filled in a few times a week. Until there is enough of your own history to judge a change, Feder says it is still learning and scores nothing, rather than guessing.
See whether you can trust the numbers in Mixpanel, one of your Visits apps. Feder only reads. It never changes anything in Mixpanel.
What else goes wrong with these numbers?
- Why did my event count drop in Mixpanel?Mixpanel
- Why did my event count jump in Mixpanel?Mixpanel
- Why did Google Analytics stop collecting data?Google Analytics
- Why aren't my key events showing in Google Analytics?Google Analytics
- Why does Google Analytics show (not set)?Google Analytics
See every question.
Where do these answers come from?
Every cause and check on this page comes from the Mixpanel help pages, quoted above with the date we read them. Last reviewed 2026-11-12. We read them again by 2027-11-12. If one changes, this page changes or comes down.