This work looks into the current state of sharing ephemeral versus permanent content on common social media platforms. Previous research has indicated that ephemerality of content, content that has an expiration date or time, can support users’ identity construction. However, not much is known about whether current ephemeral interactions on social media are successful in doing so, or whether there are ephemerality-related design opportunities for social media platforms that can improve identity expression. In an 8-day qualitative diary study, participants reported when they posted on social media, and responded to questions about the type of content they shared, their motivation, and the content’s ideal duration. We discuss our findings about short-term and long-term ephemerality as part of the social media experience, and the potential impact on the evolving identities of teenagers and young adults.