geoBoundaries API
Open administrative boundaries as an API, powered by geoBoundaries — the open database of political administrative boundaries built by the William & Mary geoLab. For more than 200 countries and every administrative level — ADM0 (national), ADM1 (states, provinces or regions), ADM2 (counties or districts) and on down to ADM4/ADM5 local units — get the boundary's metadata (official name, the source agency that produced it, the data licence, the year represented, the number of administrative units and the mean vertex count) together with direct download links to the geometry in full-resolution GeoJSON, a simplified GeoJSON, TopoJSON and a ZIP bundle; list every administrative level available for a country with its unit count and download link; and browse the full catalogue of countries that have boundaries. The geometry itself is delivered as standard GeoJSON/TopoJSON files at the returned URLs, ready to drop into Leaflet, Mapbox, QGIS, deck.gl or any GIS pipeline. Ideal for mapping and visualisation, choropleths, spatial joins, geofencing, election and census cartography and location analytics. ISO codes are 3-letter (DEU, USA, BRA); administrative levels are ADM0 to ADM5. Data from the geoBoundaries project (CC-BY 4.0).
api.oanor.com/geoboundaries-api