 Abstract OpenStreetMap, OSM, is a popular dataset used for global urban analysis, with some areas having more complete data than others. This paper examined the completeness of OSM data for 13,189 urban agglomerations worldwide, finding that 1,848 urban centres, 16%, had greater than 80% completeness, while 9,163 cities, 48%, had less than 20%. The authors also found that the unevenness of OSM data varies by population size, geographical region, and human development index group. They provided recommendations for data producers and urban analysts to manage the uneven coverage of OSM data, as well as a framework to support the assessment of completeness biases. This article was authored by Benjamin Hafort, Sven Lautenbach, Joao Porto de Albuquerque, and others.