Managing self-presentation in online communities is an integral part of private and professional life. In member profiles on social networking sites such as Facebook, people disclose intimate details that deliver a rich picture of their personality and tell stories about recent activities with colleagues, family, and friends. In communities such as Wikipedia, people selectively present personal information that is related to their effort within the community, for example, information about their interests, expertise, or professional activities. Finally, online self-presentation enables initiation of interaction, building relationships, and access to knowledge resources. The kind of personal information people present about themselves differs to a high degree between communities (Le, Beschastnikh, & McDonald, 2010;Schrammel, Köffel, & Tscheligi, 2009). Nevertheless, we do not know much about the factors that explain these differences. Are differences in self-presentation just a consequence of different opportunities to present oneself through predefined profile fields? Indeed, profiles in different communities vary in layout, content, and format. However, communities also support different kinds of interactions among their members: Social networking sites, on the one hand, support getting and staying in contact with family, friends, and colleagues. Communities focusing on content creation, on the other hand, support sharing and developing knowledge and ideas. This paper investigates whether people adapt their self-presentation in online communities to different interaction situations, independent of the profile template the community offers. For this purpose, we build on the theoretical distinction between common-bond and common-identity groups