According to UNHRC, approximately 5 million refugees fled Ukraine between the 24th of February and the 17th of April 2022. Governments and civil societies all over Europe face a major task of mobilizing resources to address the refugees’ welfare needs. This effort is partly dependent upon the mobilization of informal civil society. In this research note, we present preliminary findings from an ongoing research project on the online mobilization of informal civic action pertaining to informal groups’ temporal, geographical, and practical dimensions. Furthermore, we outline simple procedures for obtaining data on online-organized volunteering, aiming to enhance other civil society researchers’ access to studying the phenomenon.