This study analyses self-presentation practices and profiles among Spanish teenagers on Instagram and TikTok. Both of these online spaces prioritise and promote visual publications, are structured to allow feedback on self-presentation, and offer the user filters both to control self-image and to target specific audiences. Three research questions guided the methodological process for the twofold analysis of self-presentation practices on social networks: an exploratory factor analysis to identify latent factors among these practices; and a descriptive analysis of the profiles identified by gender and age. Results indicate that adolescents' self-presentation practices were related to three different factors: social validation; authenticity; and image control. One of the most outstanding results is that self-presentation practices could be less guided by social feedback, since the number of followers or likes was irrelevant for most adolescents, and that adolescents increasingly tend to be guided by innovative predispositions of truthfulness. In turn, conclusions suggest that teens need to be equipped with suitable self-representation practices for safe and sustainable identity narratives on social networks, since the global COVID-19 pandemic has exponentially increased both the usage and the time spent on social networking sites, enlarging the availability of spaces for adolescents to express themselves and build their identities through different self-representation practices.