Social media have become everyday communication channels, accompanied by technological progress through digitization and the development of mobile devices and applications. The new research project „SocialMediaHistory“, initiated and run by the authors and their team, investigates how history is being made and told on the platforms Instagram and TikTok. Together with citizen scientists, the project team analyzes narration, performativity and authenticity of audio-visual history representations. It aims at empowering citizens to analyze history in social media and to actively produce their own history contents. The article argues that social media (and historiographical practices in general) can be described as event manufactures and communication laboratories, in which events are produced in, through, and with media. Since the second half of the 20th century, there have been increasing opportunities for audiovisual, i. e. mediated participation in (media) events (in situ). Their live transmission enables people to participate in an event through the media, not as on-site witnesses, but as mediated viewers, listeners or readers. Today, more people than ever before are involved in the communicative production of meaning (in actu). Access to, participation in, or even the co-creation of historical knowledge and discourses emerges through the democratization of communication possibilities. Although the extent of participation and interaction may not necessarily lead to a general democratization of memory culture, the remediation processes in these history productions promote a rising diversity of perspectives and thus contributes to an active culture of remembrance.