Convert coordinates into country

The problem

You have geographic coordinates (longitude and latitude) and you want to know which country the location they respresent is in.

When you send a request to the OpenCage Geocoding API with each result we return (if possible, see the note below about locations that are not part of any country) various fields about the country of the result. Specifically within the components portion of each result we return

• country
  the name of the country. Example value: Germany

• ISO_3166-1_alpha-3
  the ISO 3116-1 alpha-3 code for the territory. Example value: DEU

• ISO_3166-1_alpha-2
  the ISO 3116-1 alpha-2 code for the territory. Example value: DE

• country_code
  a two-letter code for the country. Example value: de

Note that you can change the language of the country value by setting the optional language parameter when you make your API request. See the API reference . As an example if you set language=de (ie German) the returned country value will be Deutschland.

You may ask, why return both the alpha-2 code and the country_code? For historical reasons many territories have their own ISO 3116-1 codes, despite legally being part of another country. An example is Puerto Rico which has alpha-2 code PR, despite being part of the United States US.

Disputed territories

Many areas of the world are disputed or claimed by more than one country. In this case our geocoding API returns whatever in in OpenStreetMap. You can see a list of disputed territories on the OpenStreetMap wiki Our API returns whichever country OpenStreetMap deams to be valid.

It's worth nothing that the process of assigning ISO codes is not particularly quick, it may be some time before a "new" country has an official ISO code. As an example, Kosovo, recognized as a sovereign state by 98 UN member states, does not yet have an official ISO code. In this case we return just a country_code.

Locations that belong to no country

Surprisingly, most of the world - the oceans and Antartica - does not belong to any country. In this case our geocoder will return neither a country value, nor ISO_3166-1_alpha-2, ISO_3166-1_alpha-3, or country_code values in the components portion of the API result.

Because a user’s location is private information, browser geolocation is only possible if the user explicitly grants permission to a web service via a browser prompt. You can see an example of how this can look on these screenshot taken from the OpenCage demo page.

Code Example

Here's a small example of making a reverse geocoding request to the OpenCage API in javascript to detrmine the country of coordinates. We also have SDKs for over 30 other programming languages.

<script>
  var apikey = 'YOUR-API-KEY';
  var coords = '50.97755,11.32860';  // lat,lng

  var api_url = 'https://api.opencagedata.com/geocode/v1/json'

  var request_url = api_url
    + '?'
    + 'key=' + apikey
    + '&q=' + encodeURIComponent(coords)
    + '&pretty=1'
    + '&no_annotations=1';

  // see full list of required and optional parameters:
  // https://opencagedata.com/api#forward

  var request = new XMLHttpRequest();
  request.open('GET', request_url, true);

  request.onload = function() {
      // see full list of possible response codes:
      // https://opencagedata.com/api#codes
      if (request.status === 200){  // Success!
          var data = JSON.parse(request.responseText);
          var country = 'no country returned';
          if (data.results[0].components.country != null){
              country = data.results[0].components.country;
          }
          console.log('country: ' + country);
      } else {
          console.log("unable to geocode! Response code: " + request.status);
          var data = JSON.parse(request.responseText);
          console.log('error msg: ' + data.status.message);
      }
  };

  request.onerror = function() {
      // There was a connection error of some sort
     console.log("unable to connect to server");        
  };
  request.send();  // make the request
</script>

Further Reading

• OpenCage API reference section discussing the various parts of the components portion of geocoding results
• OpenCage Javascript tutorial
• OpenCage Guide to reverse geocoding

Happy geocoding!