Digital technologies offer new opportunities for citizen participation. Although scholarly interest in citizen participation in the digital era has been growing, citizens’ preferences for online versus onsite planning participation remain unclear. Drawing on survey data, this study examines public participation preferences and the factors influencing them across three phases of the planning process in China. Findings show a general preference for onsite participation, linked to more active, outcome-oriented engagement, whereas online participation is driven by convenience and expressive freedom. We propose a hybrid participation system that combines the strengths of both modes to promote more inclusive and effective collaborative planning.