Geocoding · head-to-head
adresse.data.gouv.fr vs Nominatim
The Base Adresse Nationale's API Adresse geocodes and reverse-geocodes French addresses for free with no API key, backed by Etalab and IGN's data.geopf.fr infrastructure (the old api-adresse.data.gouv.fr host now 301-redirects there). Requests and responses use the GeoJSON FeatureCollection format, with each result scored for match confidence and enriched with INSEE city codes, postcodes, and population. A live Origin-header probe confirms open CORS (Access-Control-Allow-Origin: *), so it works directly from browser JavaScript with no proxy.
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 public instance at nominatim.openstreetmap.org is a free courtesy service, not a commercial product: its usage policy caps requests at 1 per second, forbids autocomplete-style querying and bulk/parallel scripts, and requires caching results rather than re-fetching them. Heavier users are expected to self-host Nominatim against their own OSM extract instead of relying on the shared instance.
| adresse.data.gouv.fr | Nominatim | |
|---|---|---|
| Authentication | None | None |
| Pricing | free | free |
| Formats | GeoJSON | JSON, XML, GeoJSON |
| CORS | yes | yes |
| HTTPS | Yes | Yes |
Nominatim supports 3 response formats, while adresse.data.gouv.fr offers fewer — pick Nominatim for more integration flexibility.