OpenStreetMap Nominatim API
Maps & Geocoding
OpenStreetMap Nominatim is the official geocoding service built on OpenStreetMap (OSM) data, providing free geocoding (converting addresses to geographic coordinates) and reverse geocoding (converting coordinates to human-readable addresses). Nominatim is completely free, requires no API key or account registration, and is maintained as an open-source project that can be self-hosted.
OpenStreetMap Nominatim API Highlights
OpenStreetMap Nominatim API is verified for developer integrations in Nigeria and across African markets, providing documented endpoints, sandbox testing, and developer support.
None (public API include valid User-Agent header)
Public server: max 1 request/second. Self-hosted: unlimited. Must include valid HTTP User-Agent.
Nigeria
Ghana
Kenya
AWSOpenStreetMap Nominatim API is best for:
Developers needing free geocoding and reverse geocoding with no API key, no billing, and open-source flexibility. Excellent for startups, open-source projects, and self-hosted deployments with Nigeria OpenStreetMap data.
- Completely free and open source
- No API key required
- Rate limit:1 request/second on public server
- Self-hostable with no limits
OpenStreetMap Nominatim API Core Features & Capabilities
Features Included
Not Supported
Required Access Documents for OpenStreetMap Nominatim API
- No Registration RequiredOptionalPublic Nominatim API requires no API key or account. Must include a valid HTTP User-Agent header identifying your application (per usage policy). For production or high-volume usage, deploy your own Nominatim instance.
Different OpenStreetMap Nominatim API use cases
- Free Geocoding for Nigerian Open-Source Project:Use Nominatim to add geocoding to a Nigerian open-source project, NGO application, or civic tech tool without any API costs or key management simply send an HTTP request with an address and receive coordinates, respecting the 1 req/sec limit.
- Self-hosted Geocoding for High-volume Nigerian App:Deploy a self-hosted Nominatim instance loaded with Nigeria OpenStreetMap data for a high-volume Nigerian application that needs geocoding beyond Nominatim's public rate limits removing all per-request costs and rate restrictions.
- Reverse Geocoding Nigerian GPS Coordinates:Use Nominatim reverse geocoding to convert GPS coordinates from Nigerian field workers or IoT sensors to human-readable addresses identifying the street, neighborhood, and local government area for each coordinate point.
- NGO Address Database for Nigerian Civic App:Use Nominatim to geocode a database of Nigerian addresses for a civic application (health facilities, schools, water points) that needs location coordinates for mapping leveraging free, open-source geocoding suitable for nonprofit budgets.