In the light of increasing urban challenges, municipalities are developing and advancing new forms of governing. One such example is ‘urban experimentation’, a process where city-based innovation processes are initiated to test solutions that – if deemed successful – are intended to be scaled up with the ambition to leverage a broader urban sustainability transition. Research on experimental governance has shown that municipalities can play various roles in these processes, including the role as enabler. The article contributes to the literature on the roles of public actors in urban experimentation on sustainability challenges by advancing understanding of the less studied ‘enabler’ role. We probe the politics of enabling by focusing on the policy instruments employed by municipalities. Our aim is to provide deeper insights into the everyday work of urban administrations when they act in the ‘enabler’ role. One particular approach of urban experimentation is Urban Living Labs (ULL), and this paper analyses ULL that address sustainability challenges. Along the four dimensions of nodality, authority, treasury, and organisation, we identify the politics of enabling in four ULL examples from Sweden and the Netherlands.