What can the smart city discourse tell us about contemporary urbanism? This discourse is arguably a key exemplar of the increasingly mobile and networked characteristic of urban policy-making, and can reveal important insights into the policy processes currently shaping cities. For that purpose, this paper empirically examines smart city networks funded by the European Union, in particular three so-called ‘Lighthouse cities’ for smart city development – Nottingham, Stavanger and Stockholm – and their contested local implementation. On the basis of these cases, we highlight three characteristics that emerge when smart city policies are made mobile: glossiness, fragmentation and randomness. We propose that with intensifying policy mobility these qualities may be increasingly important features of contemporary urban policy-making, that condition possibilities to govern cities in response to critical urban challenges.