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Version: v1

Identify Users

Identify a user

Each time a page loads for a user you can identify, you'll want to call the FS.identify function to associate your own application-specific id with the active user.

    uid string required

    A string containing your unique identifier for the current user.

    userVars object optional

    A JSON object with key/value pairs that provides additional information about your user.


Fullstory doesn't let you change the identity of a user once they have been assigned a unique user ID using FS.identify. If you attempt to change the user id of an identified user, Fullstory will recognize the new user ID and automatically split the session into a new session.


  • Sustained calls are limited to 30 calls per page per minute with a burst limit of 10 calls per second.

Additional Information

FS.identify(uid, userVars?)

Example Invocation

FS.identify('462718483', {
displayName: 'Daniel Falko',
email: ''