This paper reports the development of a method for increasing the diversity in public archives, referred to as the Co-archiving Toolbox and developed in collaboration with three museums. Museum professionals and refugees were invited to co-design workshops to explore and prototype alternative ways to document and archive refugee stories – told in their own voices and through their own perspectives. Besides elaborating on alternative, and more inclusive archiving practices, the project also explored how co-design approaches and prototyping can become a resource in rethinking the role of archivists and museum professionals who are interested in coarchival facilitation. The co-archiving toolbox currently includes seven co-archiving practices designed to be applied at temporary refugee housing but could potentially also be used in other contexts. The project may serve as an example of how design interventions can contribute to developing existing archival practices by encouraging archivists and museum professionals to assume a collaborative approach.