This article seeks to expand knowledge about spontaneous volunteering in Amsterdam during the European refugee crisis in the winter of 2015–16. As formal institutions, which relied on a top–down command and control approach, were unable to handle the relatively large number of refugees who arrived in a short period of time, grassroots social movements based on bottom–up participation emerged. Grassroots volunteers were not only politically engaged, protesting against the strict refugee reception policy, but they also became involved in the crisis response, showing a great deal of flexibility. Although the social movements struggled with their organizational structures, they were able to adapt their missions and structures to changing circumstances. To achieve a resilience‐based response to future refugee influxes, this article advocates for formal response organizations to dismantle their static, top–down approach, and for social movements to find a balance between participation and professionalism. If institutionalized refugee response organizations adapt to the dynamics of local conditions, they could create the conditions for resilient solutions in the crisis context.