Techniques for session-based device grouping are described. In an example, a computer system receives first data requesting an output, determines a function to provide content data based at least in part on the first data, determines a session identifier of a session associated with execution of the function, and determines session data associated with the session identifier. The session data includes a first device identifier of a first device, an indication that the first device is outputting the content data, and a second device identifier of a second device. The computer system also causes, based at least in part on the session data including the second device identifier, the second device to output the content data.