Difference between Client ID and User ID in Google Analytics

Difference between Client ID and User ID in Google Analytics

In google analytics, client id and user id are two different features similar to behavior flow and user flow. Below is a difference explained:

difference between client id and user id

difference between client id and user id

A bit more explanation about the difference between client id and user id.

  1. Client id represents an unknown browser or device while user id only represents a unique user.
  2. Client id is randomly generated by universal analytics cookie _ga. For user id, you have to pull the login ids from your authentication system and send to GA as a user id.
  3. Client id is assigned to all website visitors while user id is only applied to login users(you can not track what a non-logged visitor did with user id).
  4. Client id reports are available in every reporting view (Audience >> user explorer) whereas user id reports you need to create new reporting view.
  5. Client id consists of a random number with time stamp separated by a dot. User id only consists of random alphanumeric characters. Time stamp means the time of the first visit.
  6. User id can exist across multiple devices which makes cross-device tracking possible in GA. Client id only exists on the device or browser it has been setup.
  7. The attribution of user engagement is possible with user id because it can exist on multiple devices while with client id create attribution issues.