Overview
Nominatim is a free geocoding API powered by OpenStreetMap data that lets you convert addresses to coordinates (forward geocoding) and coordinates back to addresses (reverse geocoding). It covers the entire world and requires no API key for low-volume use. It is a great choice for open-source projects that need location lookup without licensing costs.
Beginner Tip
Always set a custom User-Agent header with your app name and contact email — Nominatim requires it and will block requests without one. Limit your requests to 1 per second to comply with the usage policy.
Measurement Record
What actually happened when we called this API from our own infrastructure. Every value below was recorded by the request, not copied from the provider's documentation.
- Request
- GET https://nominatim.openstreetmap.org/search?q=Eiffel+Tower+Paris&format=json&limit=1
- Result
- HTTP 200 · application/json · 539 bytes · compressed
- Response time
- 29 ms (median of 3) · fastest 23 ms
- Transport
- TLSv1.3 · TLS_AES_128_GCM_SHA256 · certificate issued by Let's Encrypt
- Browser CORS
- Allowed — Access-Control-Allow-Origin: *
- Served by
- gunicorn/asgi
- Recorded
- 2026-08-10
Fields Returned
Top-level fields present in the response we captured, with the type and value we actually received.
| Field | Type | Value received |
|---|---|---|
| place_id | integer | 97582011 |
| licence | string | Data © OpenStreetMap contributors, ODbL 1.0. … |
| osm_type | string | way |
| osm_id | integer | 5013364 |
| lat | string | 48.8582599 |
| lon | string | 2.2945006 |
| class | string | man_made |
| type | string | tower |
| place_rank | integer | 30 |
| importance | number | 0.6205937724353116 |
| addresstype | string | man_made |
| name | string | Tour Eiffel |
| display_name | string | Tour Eiffel, 5, Avenue Anatole France, Quarti… |
| boundingbox | array | [1 item] |
Captured Response
Captured from a real request to https://nominatim.openstreetmap.org/search?q=Eiffel+Tower+Paris&format=json&limit=1 on 2026-08-10. Long arrays and nested objects are truncated to keep the shape readable.
[
{
"place_id": 97582011,
"licence": "Data © OpenStreetMap contributors, ODbL 1.0. http://osm.org/copyright",
"osm_type": "way",
"osm_id": 5013364,
"lat": "48.8582599",
"lon": "2.2945006",
"class": "man_made",
"type": "tower",
"place_rank": 30,
"importance": 0.6205937724353116,
"addresstype": "man_made",
"name": "Tour Eiffel",
"display_name": "Tour Eiffel, 5, Avenue Anatole France, Quartier du Gros-Caillou, Paris 7e Arrondissement, Paris, Île-de-France, France métropolitaine, 75007, France",
"boundingbox": [
"48.8574753"
]
}
] Implementation Example
Calls a real endpoint of this API. Replace any placeholder credentials with your own key.
const url = "https://nominatim.openstreetmap.org/search?q=Eiffel+Tower+Paris&format=json&limit=1";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data); What Can You Build?
Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.
How This API Fails
We deliberately sent this API a broken request and recorded exactly what came back on 2026-08-10. Knowing the shape of an error before you hit it makes error handling much easier to write.
{
"title": "404 Not Found"
} Common Errors & Troubleshooting
Generated guidance based on this API's documentation, not observed by us. Treat it as a starting point and check against the provider's own error reference.
Measured Score Breakdown
Live HTTP request to the API endpoint
Fully tested on Aug 10, 2026
Technical Specifications
Related Tags
Alternatives to Nominatim
Technical alternatives for different use cases.
Free OpenStreetMap-based geocoding, self-hostable
Structured US address parsing and verification
Self-hosted geocoding without API limits
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