Nominatim API

Beginner's Pick Geocoding / No Auth Required Beginner HTTPS CORS
Free to Use
86 A
Measured Score 0 50 100 Speed 30/30 Consistency 13/20 Security 20/20 Browser access 15/15 Transparency 8/15 TESTED 2026-08-10

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.

JSON Response · Captured
[
  {
    "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.

Request
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.

HTTP 404 Requesting a path that does not exist application/json
{
  "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.

429 Too Many Requests You are sending more than 1 request per second
Add a delay of at least 1 second between requests; for bulk geocoding, use a local Nominatim instance instead
Empty results array The address could not be found or is too ambiguous
Add country or city context to the query (e.g., "Berlin, Germany") and avoid abbreviations
Blocked requests Missing or generic User-Agent header
Set the User-Agent header to something identifying your application, like "MyProjectName [email protected]"

Measured Score Breakdown

Live HTTP request to the API endpoint

Speed 30/30
Consistency 13/20
Security 20/20
Browser access 15/15
Transparency 8/15
Endpoint Response Time 29ms

Fully tested on Aug 10, 2026

Technical Specifications

Auth No Auth
HTTPS REQUIRED
CORS YES
Category Geocoding
Difficulty Beginner
Endpoint last called: 2026-08-10

Related Tags

Alternatives to Nominatim

Technical alternatives for different use cases.

Free OpenStreetMap-based geocoding, self-hostable

Better For

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Trade-off

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