The P4URB project is based on the key idea that participation is essential for successful, inclusive and sustainable urban development. In P4URB, we investigate how post-digital participation in formal urban development processes contributes to evidence-based and humancentric planning. Cities are arenas in which processes of democratic involvement through participation were first established in the 1960s and 1970s. In Germany, the Building Code (BauGB) regulates how the public is to participate in planning (BauGB, §3). In planning practice, a distinction is often made between formal and informal participation (and their hybrid forms). New technological possibilities offer the chance to design participation processes in such a way that they are socially "broadly" supported. However, up to now, many methods of planning participation have not been digital and at the same time, the potential opportunities offered by digital tools have only been tapped to a limited extent - so our hypothesis. With P4URB, we are therefore exploring how concepts of participation can be transferred to the post-digital era. We are exploring this together with actors from civil society and planning practice in target group-specific formats. Our objective is to develop methods and instruments for post-digital participation in formal urban planning together with the diverse future users.