Users vs unique visitors (not equal)

Hello there

I am tracking a website with “setUserId”.

For any given day, there are more unique visitors than users (e.g. 1200 unique visitors, 1000 users). From my understanding these numbers should be equal (there are only visits with a userId in the visitor log)

Is there an explanation for this difference?

Thanks in advance Best

The difference seems to be correct. According to

When a same person visits your website on two different devices (for example their laptop and on their mobile phone) then Matomo (Piwik) will detect two unique visitors.

1 Like

Thanks for the reply.

The problem was solved once we upgraded to Matomo 4 - therefore it was probably a Bug in Matomo 3.

Now users and unique visitors are equal as expected.

See also: Users & Unique Visitors numbers are identical - General questions - Matomo forums