Unique new visitors and unique returning visitors don't add up

First of all thanks for all the helpful information in your FAQ and the glossary!

Judging from the definitions (https://matomo.org/faq/general/faq_36/; https://matomo.org/faq/general/faq_21418/; https://glossary.matomo.org/#/metrics):

visits= new visits + returning visits
unique visitors = unique new visitors + unique returning visitors

where unique visitors are a subset of all the visits recorded and
new visits are identical to unique new visitors.

I tried to validate whether my assumption regarding the relationship between the different kinds of visits is correct. We use Matomo 4.10.1 to collect user statistics from our website.

“new visits + returning visits” matches the number of visits recorded
BUT
“unique new visitors + unique returning visitors” is larger than the number of unique visitors recorded.

How come?

Hi @WBreustedt,
Your graph is not true. A visitor is not the same as a visit.
If as a visitor I visit your site during 10 minutes at 08:00, then I come back at 11:00. Then I will be counted as one unique visitor who did 2 visits…

@heurteph-ei,

they are not the same, but they are nevertheless related. Hence the subset relationship.
The FAQ posts I cited above explain how.

From what I gather:

A unique visitor that visits my page for the very first time is recorded as a new visit.

Whenever a unique visitor visits my page (for a second, a third, a fourth time at least more than 30 minutes after the prior visit) the visitor’s visit is counted as a returning visit.

Together, the unique visitors’ new (aka 1st) visits and their returning visits make up all of the persons’ visits to my website.

A unique visitor that visits my page for the very first time is recorded as a unique new visitor (which is the same as a new visit, judging from the numbers recorded by Matomo on our page).

A unique visitor that visits my page for the second, third, fourth time at least more than 30 minutes after the prior visit is considered a unique returning visitor.

Together, the unique new visitors and unique returning visitors should add up to the number of unique visitors. But they don’t. I assume this is because there are multiple ways to determine whether a unique visitor returns to the website (https://matomo.org/faq/general/faq_21418/) but I am not sure, hence my post.

Do you have some screenshot that could illustrate this? (do you also use some kind of filter or segment in your report?)

These are the numbers for the past month. I did not use a segment. The numbers do not refer to all of our website, however, just part of it.

Maybe if a user visits for the first time your site, then comes back during the same day (as new visit), it is counted twice in term of visitor categories… Once as new visitor and once as returning visitor?
What is the opinion of @innocraft about this?