Visitors without "Session number", how is that possible


We want to see how many of our users that visit our site one time, two times etc in a given period of time. To accomplish this, we’ve created a custom report with Session number as dimension and Visitors as metric.

However, a large portion of the visitors, about 25% do not show up with a Session number at all.

It looks something like this:

Session number                            Visitors
1                                         3000
2                                         2000
3                                         800

We don’t understand how it’s possible that a visitor has zero sessions. And since the portion that lacks session number is so large, it can’t be written off as error margin.

What could be causing this?

Hi @klaseen,

Could you please share with me via DM on what instance and site you see this problem?


Hi @klaseen,

The number of visitors in session number 2 are available in session 1 as well (depending on the reporting period, that is), so they are counted in session one, but also in session two.

These sum of these amount of visitors per line does hardly ever match the total number of visitors because they visited both session 1 and session 2.

It is the same for visitors in a pageview, or number of sessions.

The total is a sum of all visitors.
than each line shows the amount of visitors that fall into that group;
The individual lines are a total of visitors that e.g had session number 1
the total amount of visitors that had session number 2


Thank you!

But can you please explain how it is possible that if we have say 5000 visitors, only 3000 have at least one session? How can we have visitors with zero sessions? Does not every visitor create a new session?

It’s because of the time period you’ve selected.
The number there is for visitors that had a session with a session number 1.
Let’s say:
A visitor had their first session in march and second session in april.
If you look at data for april you’ll see that this visitor have 0 for first session and 1 for second session.

Aha, then I understand! So you could say that the time for each session is taken into account when filtering.

Then it is not strictly true that all visitors with two sessions are also counted as one session. This is only true if both these sessions occurred in the time period selected.

Although this makes sense in a way, I don’t find it intuitive. It would be very good if you could update the documentation regarding this, since understanding what the numbers mean is a very important part of analysis.

Thanks for clearing it up!