Credit Is Due

OpenCage is built with open source software and open data.


This is a full list of the projects we rely on to build the OpenCage geocoding API and geosearch.

It's our pleasure to support some of these projects financially and by helping maintain the software. Read more about our efforts to support geo-innovation.


Nominatim and OpenStreetMap

Data OpenStreetMap and contributors under ODbL. GPL v2.

Please note the OpenStreetMap Foundation's guidelines around geocoding, specifically the view that geocoding does not trigger the share-alike obligations of the ODbL.

We're proud to support OpenStreetMap by being corporate members of the OpenStreetMap Foundation, FOSSGIS e.V. (the official Local Chapter of OSMF for Germany) and the OpenStreetMap United Kingdom CIC.

We're running a data mirror of the OpenStreetMap weekly database export.


Data contributors and licenses are on the about page. Source code dual licensed under the MIT and GPL licenses.


Data under CC-BY. Data sources page.


The free and open global address collection.


Data under CC-BY. Apache 2.0.


The what3words Server Software converts searches that are compatible with what3words into geographic coordinates, and converts geographic coordinates into what3words.

Data under OS OpenData licence. Data sources page.

Yahoo GeoPlanet

Data under CC-BY.


Data under ODbL licence.


A C library for parsing/normalizing street addresses around the world.


©PSMA Australia Limited licensed by the Commonwealth of Australia under the Open Geo-coded National Address File (G-NAF) End User Licence Agreement.

Data under CC BY 4.0, with the additional restriction that the open G-NAF data must not be used for the generation of an address or the compilation of an address for the sending of mail unless the user has verified that each address to be used for the sending of mail is capable of receiving mail by reference to a secondary source of information.

Canadian postcodes

Crowdsourced Canadian postal codes dataset


United Nations Code for Trade and Transport Locations, a public domain dataset that assigns codes to locations used in trade and transport.

Mapzen Terrain Tiles

  • Attribution
  • ArcticDEM terrain data DEM(s) were created from DigitalGlobe, Inc., imagery and funded under National Science Foundation awards 1043681, 1559691, and 1542736;
  • Australia terrain data © Commonwealth of Australia (Geoscience Australia) 2017;
  • Austria terrain data © offene Daten Österreichs – Digitales Geländemodell (DGM) Österreich;
  • Canada terrain data contains information licensed under the Open Government Licence – Canada;
  • Europe terrain data produced using Copernicus data and information funded by the European Union - EU-DEM layers;
  • Global ETOPO1 terrain data U.S. National Oceanic and Atmospheric Administration
  • Mexico terrain data source: INEGI, Continental relief, 2016;
  • New Zealand terrain data Copyright 2011 Crown copyright (c) Land Information New Zealand and the New Zealand Government (All rights reserved);
  • Norway terrain data © Kartverket;
  • United Kingdom terrain data © Environment Agency copyright and/or database right 2015. All rights reserved;
  • United States 3DEP (formerly NED) and global GMTED2010 and SRTM terrain data courtesy of the U.S. Geological Survey.

Behind the API

What makes OpenCage run? We're glad you asked ...

The OpenCage geocoding API is an aggregating API. Every query you shoot at the API generates calls to the various back-end geocoders we have installed.

The bulk of the geocoder code is written in Perl, apart from the back-end geocoders which are written in a whole plethora of languages.

We rely on many different tools and services to operate our business. We regularly feature them in an ongoing "Tools we use" series on our blog. If you've read this far you may also enjoy this discussion with one of our founders on the Pushing to Production podcast.

Please take a peak at the various software projects we've opensourced.

The API is served by HAProxy and Apache, and the whole lot runs on top of servers running ubuntu, a version of Linux.

Icons CC BY-4.0 Font Awesome

For preselecting currency and country on our payment pages we use MaxMind GeoLite2 database, CC BY-SA 4.0

Flaticon Icons, by author: Andrejs Kirma (4867798), ChilliColor (7508926), Eucalyp (4363531, 2166832, 3676408), Freepik (2541979, 1341632, 8465041, 10988190, 7666480, 4645352), Muhammad_Usman (8942070), Uniconlabs (8439120), juicy_fish (9482304), photo3idea_studio (2808516)

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