Nominatim/docs/api/Reverse.md
2022-06-17 21:01:38 +02:00

8.3 KiB

Reverse Geocoding

Reverse geocoding generates an address from a latitude and longitude.

How it works

The reverse geocoding API does not exactly compute the address for the coordinate it receives. It works by finding the closest suitable OSM object and returning its address information. This may occasionally lead to unexpected results.

First of all, Nominatim only includes OSM objects in its index that are suitable for searching. Small, unnamed paths for example are missing from the database and can therefore not be used for reverse geocoding either.

The other issue to be aware of is that the closest OSM object may not always have a similar enough address to the coordinate you were requesting. For example, in dense city areas it may belong to a completely different street.

Parameters

The main format of the reverse API is

https://nominatim.openstreetmap.org/reverse?lat=<value>&lon=<value>&<params>

where lat and lon are latitude and longitude of a coordinate in WGS84 projection. The API returns exactly one result or an error when the coordinate is in an area with no OSM data coverage.

Additional parameters are accepted as listed below.

!!! warning "Deprecation warning" The reverse API used to allow address lookup for a single OSM object by its OSM id. This use is now deprecated. Use the Address Lookup API instead.

Output format

  • format=[xml|json|jsonv2|geojson|geocodejson]

See Place Output Formats for details on each format. (Default: xml)

  • json_callback=<string>

Wrap JSON output in a callback function (JSONP) i.e. <string>(<json>). Only has an effect for JSON output formats.

Output details

  • addressdetails=[0|1]

Include a breakdown of the address into elements. (Default: 1)

  • extratags=[0|1]

Include additional information in the result if available, e.g. wikipedia link, opening hours. (Default: 0)

  • namedetails=[0|1]

Include a list of alternative names in the results. These may include language variants, references, operator and brand. (Default: 0)

Language of results

  • accept-language=<browser language string>

Preferred language order for showing search results, overrides the value specified in the "Accept-Language" HTTP header. Either use a standard RFC2616 accept-language string or a simple comma-separated list of language codes.

Result limitation

  • zoom=[0-18]

Level of detail required for the address. Default: 18. This is a number that corresponds roughly to the zoom level used in XYZ tile sources in frameworks like Leaflet.js, Openlayers etc. In terms of address details the zoom levels are as follows:

zoom address detail
3 country
5 state
8 county
10 city
14 suburb
16 major streets
17 major and minor streets
18 building

Polygon output

  • polygon_geojson=1
  • polygon_kml=1
  • polygon_svg=1
  • polygon_text=1

Output geometry of results as a GeoJSON, KML, SVG or WKT. Only one of these options can be used at a time. (Default: 0)

  • polygon_threshold=0.0

Return a simplified version of the output geometry. The parameter is the tolerance in degrees with which the geometry may differ from the original geometry. Topology is preserved in the result. (Default: 0.0)

Other

  • email=<valid email address>

If you are making a large number of requests, please include an appropriate email address to identify your requests. See Nominatim's Usage Policy for more details.

  • debug=[0|1]

Output assorted developer debug information. Data on internals of Nominatim's "Search Loop" logic, and SQL queries. The output is (rough) HTML format. This overrides the specified machine readable format. (Default: 0)

Examples

  <reversegeocode timestamp="Fri, 06 Nov 09 16:33:54 +0000" querystring="...">
    <result place_id="1620612" osm_type="node" osm_id="452010817">
      135, Pilkington Avenue, Wylde Green, City of Birmingham, West Midlands (county), B72, United Kingdom
    </result>
    <addressparts>
      <house_number>135</house_number>
      <road>Pilkington Avenue</road>
      <village>Wylde Green</village>
      <town>Sutton Coldfield</town>
      <city>City of Birmingham</city>
      <county>West Midlands (county)</county>
      <postcode>B72</postcode>
      <country>United Kingdom</country>
      <country_code>gb</country_code>
    </addressparts>
  </reversegeocode>
Example with format=jsonv2
{
  "place_id":"134140761",
  "licence":"Data © OpenStreetMap contributors, ODbL 1.0. https:\/\/www.openstreetmap.org\/copyright",
  "osm_type":"way",
  "osm_id":"280940520",
  "lat":"-34.4391708",
  "lon":"-58.7064573",
  "place_rank":"26",
  "category":"highway",
  "type":"motorway",
  "importance":"0.1",
  "addresstype":"road",
  "display_name":"Autopista Pedro Eugenio Aramburu, El Triángulo, Partido de Malvinas Argentinas, Buenos Aires, 1.619, Argentina",
  "name":"Autopista Pedro Eugenio Aramburu",
  "address":{
    "road":"Autopista Pedro Eugenio Aramburu",
    "village":"El Triángulo",
    "state_district":"Partido de Malvinas Argentinas",
    "state":"Buenos Aires",
    "postcode":"1.619",
    "country":"Argentina",
    "country_code":"ar"
  },
  "boundingbox":["-34.44159","-34.4370994","-58.7086067","-58.7044712"]
}
Example with format=geojson
{
  "type": "FeatureCollection",
  "licence": "Data © OpenStreetMap contributors, ODbL 1.0. https://osm.org/copyright",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "place_id": "18512203",
        "osm_type": "node",
        "osm_id": "1704756187",
        "place_rank": "30",
        "category": "place",
        "type": "house",
        "importance": "0",
        "addresstype": "place",
        "name": null,
        "display_name": "71, Via Guglielmo Marconi, Saragozza-Porto, Bologna, BO, Emilia-Romagna, 40122, Italy",
        "address": {
          "house_number": "71",
          "road": "Via Guglielmo Marconi",
          "suburb": "Saragozza-Porto",
          "city": "Bologna",
          "county": "BO",
          "state": "Emilia-Romagna",
          "postcode": "40122",
          "country": "Italy",
          "country_code": "it"
        }
      },
      "bbox": [
        11.3397676,
        44.5014307,
        11.3399676,
        44.5016307
      ],
      "geometry": {
        "type": "Point",
        "coordinates": [
          11.3398676,
          44.5015307
        ]
      }
    }
  ]
}
Example with format=geocodejson

https://nominatim.openstreetmap.org/reverse?format=geocodejson&lat=60.2299&lon=11.1663

{
  "type": "FeatureCollection",
  "geocoding": {
    "version": "0.1.0",
    "attribution": "Data © OpenStreetMap contributors, ODbL 1.0. https://osm.org/copyright",
    "licence": "ODbL",
    "query": "60.229917843587,11.16630979382"
  },
  "features": {
    "type": "Feature",
    "properties": {
      "geocoding": {
        "place_id": "42700574",
        "osm_type": "node",
        "osm_id": "3110596255",
        "type": "house",
        "accuracy": 0,
        "label": "1, Løvenbergvegen, Mogreina, Ullensaker, Akershus, 2054, Norway",
        "name": null,
        "housenumber": "1",
        "street": "Løvenbergvegen",
        "postcode": "2054",
        "county": "Akershus",
        "country": "Norway",
        "admin": {
          "level7": "Ullensaker",
          "level4": "Akershus",
          "level2": "Norway"
        }
      }
    },
    "geometry": {
      "type": "Point",
      "coordinates": [
        11.1658572,
        60.2301296
      ]
    }
  }
}