Great expectations are being projected onto digital transformation as a solution to planning under uncertainty and complexity, while demanding new skills from and posing challenges to professionals. We address the ambivalent inclusion of information and communication technologies (ICTs) in everyday planning practices. How do ambivalences towards digitalisation as either a transformative process or as an intrusion upon everyday routines play out in urban planning as a situated knowledge practice? We focus on the erratic embedding of digital technologies and data into planning practices. We gather insights from interviews with planners in small and medium-sized cities in Germany, Austria and Switzerland. The analytical focus on knowing in practice and situated knowledge allows for insights on how digital transformations shape planning from professionals’ perspectives. Our research shows that digital transformation requires infrastructure and routines to bring forward innovative ambitions, which in many contexts are disrupted by limited resources and hierarchical decision-making procedures.