Cartes.io vs Nominatim

Cartes.io is an open-source platform for creating and sharing custom maps with markers, letting anyone plot points, GeoJSON shapes, and metadata without running their own server. Reading public maps and markers needs no signup — write access is optional and controlled per map, either open to anyone or gated behind a token issued when the map or marker is created. The API returns JSON by default and GeoJSON on request, and the project ships official Python and NPM packages alongside its hosted instance at cartes.io.

Nominatim provides worldwide forward and reverse geocoding built entirely on OpenStreetMap data, needing no API key — only a descriptive User-Agent or Referer header identifying the calling application (the policy states a stock HTTP-library User-Agent will not do). The public instance at nominatim.openstreetmap.org mainly exists to power the search bar on openstreetmap.org and runs on donated servers with very limited capacity: its usage policy caps requests at an absolute maximum of 1 per second, forbids autocomplete-style querying outright, and requires results to be cached on the caller's side. Bulk geocoding is restricted rather than banned — a smaller one-time task is permissible on a single thread and a single machine, with distributed scripts disallowed and anything running longer than a day capped at 4 requests per minute. The policy points larger users first at commercial third-party providers, and the largest at running their own Nominatim instance.