Urban parks are important for public health, but the role of specific spaces, such as playgrounds or lakes, and elements, such as benches or sports equipment, in supporting well-being is not well understood. Here, based on expert input and a review of the literature, we defined six types of health-related activity: physical, mindfulness, nature appreciation, environmental, social and cultural. We built a lexicon that links each activity to specific elements and spaces within parks present in OpenStreetMap. Using these data, we scored 23,477 parks across 35 cities worldwide on the basis of their ability to support these activities. We found clear patterns: parks in North America focus more on physical activity, while those in Europe offer more chances to enjoy nature. Parks near city centers support health-promoting activities better than those farther out. Suburban parks in many cities lack the spaces and equipment needed for nature-based, social and cultural activities. We also found large gaps in park quality between cities. Tokyo and Paris provide more equal access, while Copenhagen and Rio de Janeiro show sharp contrasts. These results can help cities create fairer parks that better support public health. City parks clearly promote health, but understanding the distribution of healthful park elements and spaces is challenging. This study scored thousands of parks across 35 major cities worldwide and found that North American parks emphasize physical activity, European parks more often promote nature appreciation and centrally located parks tend to better support health-promoting activities.