This study describes the co-design process, which includes the
citizens’ spatial experiences, needs, and wishes, through participatory digital design tools in urban design. The paper draws on a case study for co-design practices for leftover public space; Re-shapin Küçük Park urban void in Bornova, Izmir, Turkey. The methodology used in this study is a further improvement of ‘Citizen Design Science’ and its tool Qua-Kit (a map-based e-participation tool), which originated from Future Cities Laboratory (FCL) in ETH Zurich. The toolkit allows users to move geometries in given urban spaces and enables non-expert participants to express their ideas for the urban area through design. Departing from conventional urban design approaches, the shaping of the urban realm became a democratic process in which all stakeholders participated as co-designers. The study utilizes objective and subjective design data, offering a novel perspective on urban design education and the profession. The educational experiment showed that participants could contribute their experiences and opinions through active design tools and the development process in co-designing public spaces.