Abstract: Public sharing is integral to online platforms. This includes the popular multimedia messaging application Snapchat, on which public sharing is relatively new and unexplored in prior research. In mobile-first applications, sharing contexts are dynamic. However, it is unclear how context impacts users’ sharing decisions. As platforms increasingly rely on user-generated content, it is important to also broadly understand user motivations and considerations in public sharing. We explored these aspects of content sharing through a survey of 1,515 Snapchat users. Our results indicate that users primarily have intrinsic motivations for publicly sharing Snaps, such as to share an experience with the world, but also have considerations related to audience and sensitivity of content. Additionally, we found that Snaps shared publicly were contextually different from those privately shared. Our findings suggest that content sharing systems can be designed to support sharing motivations, yet also be sensitive to private contexts.