As we all know, GA4 identifies the user based on the _ga (Client ID) in the cookie.
But in GA4, new users is calculated based on the number of first_visit/first_open events.
If there is a lack of first_visit/first_open, the number of new users will decrease, this situation usually occurs in the Measurement Protocol. For new users, no first_visit/first_open is sent. Then it will not be calculated in the number of new users.
The default user in GA4 is actually an active user, and an active user is any user that includes engaged sessions; it can be understood that an active user includes engaged sessions.
An engaged session is a user visit that lasts 10 seconds or longer, or a visit with 1 or more conversion events or 2 or more page views.
The parameter seg on the request sent to the GA4 server indicates whether engaged sessions are engaged, 1 indicates yes, and 0 indicates no.
Total Users is the total number of unique users who recorded events, corresponding to the users in UA.
The default Users in GA4 are active users with specific requirements, so Users will be smaller than New Users.
New Users>Total Users
There are following possibilities:
- Wrongly enable first_visit or first_open, some users will start a new session when opening a web page in another tab, and will also send first_visit or first_open
- “Report identification information” enables mixing or has been listed as an observation item, and the user is identified and regarded as the same user. For example, I visit through device A for the first time, send first_vist, and then I log in to the account (User has been set User ID), in the afternoon I used device B, which is also the first time to visit, send first_visit, and also log in to the account. If the “report identification information” is enabled for mixing or has been listed as an observation item, since the account is logged in and the User ID is set, so If the same user is recognized, then the Total Users during this period is 1, and the New Users is 2.
New Users+Returning Users> Total Users
For example, if a person visits for the first time in the morning and visits again in the afternoon (the interval is more than 30 minutes), then on this day, New Users is 1, Returning Users is 1, and Total Users is 1.
New Users+Returning Uses=1+1=2, greater than 1 of Total Users.