Online conference collaboration techniques and systems are described in which a plurality of client devices may be leveraged by a single user to participate as part of an online conference. In one example, a user input is received that is initiated as part of the online conference by a first client device. The user input identifies a portion of a plurality of portions of a user interface that support user participation as part of the online conference by the first client device and a second client device that is to output the identified portion. In response, the second client device is caused to join the online conference and caused to display the identified portion of the user interface.