Topics covered in this tutorial
Background
Before we dive in to the tutorial
- Sign up for an OpenCage geocoding API key.
- Play with the demo page, so that you see the actual response the API returns.
- Browse the API reference, so you understand the optional parameters, best practices, possible response codes, and the rate limiting on free trial accounts.
jQuery geocoding example:
<script>
// load jQuery from a CDN or your server
function geocode(query){
$.ajax({
url: 'https://api.opencagedata.com/geocode/v1/json',
method: 'GET',
data: {
'key': 'YOUR-API-KEY',
'q': query,
'no_annotations': 1
// see other optional params:
// https://opencagedata.com/api#optional-params
},
dataType: 'json',
statusCode: {
200: function(response){ // success
console.log('formatted: ' + response.results[0].formatted);
console.log('coords: ', response.results[0].geometry);
},
401: function(){
console.log('invalid API key');
},
402: function(){
console.log('hit free trial daily limit');
console.log('become a customer: https://opencagedata.com/pricing');
}
// other possible response codes:
// https://opencagedata.com/api#codes
}
});
}
$(document).ready(function(){
// reverse geocoding example
geocode('50.97751,11.32858');
// console should now show:
// 'formatted: Goethe-Nationalmuseum, Frauenplan 1, 99423 Weimar, Germany'
// 'coords: Object { lat: 50.9775106, lng: 11.3285424 }'
//
// forward geocoding example
// note: no need to URI encode query, jquery's ajax method does it
geocode('Frauenplan 1, 99423 Weimar, Germany');
// console should now show:
// 'formatted: Goethe-Nationalmuseum, Frauenplan 1, 99423 Weimar, Germany'
// 'coords: Object { lat: 50.9775106, lng: 11.3285424 }'
});
</script>
Some issues to consider:
Please note that putting your API key in client side javascript means that it is visible to anyone executing that javascript. We recommend you do this only for internal applications.
Please see our detailed guide to protecting your API key(s).
As an added measure of safety subscription customers can define a value for
the
Access-Control-Allow-Origin
header in their account dashboard which will limit AJAX requests to
a specific domain. You can find the
details in the API documentation.
That being said, one worry that potential clients sometimes raise is that someone will get their key and start using it heavily and they will face a large and unexpected bill. Fear not - that can't happen because of how our pricing works. Subscription customers buy a month in advance, and there is no usage-based charging. If we see an explosion of usage we email you and ask if it is expected and the source is known. If yes, and it will be ongoing, we ask you to move to a higher pricing tier in the future, but this never happens as a surprise. If no, we can help you work out what is going on. Please see all the details of how our pricing works.