MoEngage enables you to have a single user ID for all your users, even if they are using different devices. When a user visits your website or app, MoEngage merges the anonymous user profile with the registered user profile after they log in to the system. For more information on user merging, refer to User Merging.

Perform the following steps to enable user merging:

1. On the left navigation menu in the MoEngage dashboard, go to Settings > Analytics > User merging.
2. On the User merging page, turn the Analytics user merging toggle on.