Selecting user device during communications session

This disclosure describes, in part, techniques for establishing network-based data communications (e.g., voice calls, video calls, etc.) between a user device of a user and a remote device of another user, and transitioning the data communications to a different user device of the user based on various types of information. In some examples, the user devices may be located in one or more environments of the user, and the data communications may be transitioned between the user devices based, at least in part, on a location of the user in the environment(s) relative to the multiple devices. For instance, if a user device is performing data communications with the remote device, but it is determined that the user has moved into a closer proximity to another user device, the performance of the data communications may be transitioned to the other user device to which the user is in closer proximity.