Cities and regions worldwide want to promote sustainable mobility in the sense of the 15-minute city. To support decision-making, Plan4Better is developing the digital accessibility tool GOAT to help planners and decision-makers design sustainable cities and regions. GOAT shows the current situation (e.g. how many people have access to a supermarket within 5 minutes) and allows to interactively develop and evaluate scenarios. The web tool is offered as a software-as-a-service solution.