coordinates and houses

Reverse Geocoding Guide

A comprehensive guide to building, using, and running a reverse geocoder without Google or other proprietary data sources.

This guide digs into what reverse geocoding is, and how reverse geocoders are used and built. It then walks you through implementing a reverse geocoding project yourself, and gives you resources to expand your knowledge of working with geo data.

street of houses and coordinates

Introduction to Reverse Geocoding

We start with the basics: what exactly is reverse geocoding? How does it differ from forward or "normal" geocoding? What should you consider when choosing a reverse geocoder? From there, it's hands on. Make a call to a reverse geocoder API and see what the results look like in JSON. See how you can make calls from within your code and what you should consider when choosing (or building) a reverse geocoder.

vehicles with coordinates

Why Use a Reverse Geocoder?

Wherever there's a need for location-specific intelligence, a reverse geocoder can help. Using the coordinates from a device, determine local information, such as an address, a road, or a nearby landmark. Or effectively "zoom out" to understand the user's postal code, city, or country. There are many use cases for reverse geocoding across industries and applications. See how reverse geocoding is used in fleet tracking, Internet of Things, and other geo-aware practices.

developer studying map

How a Reverse Geocoder Works

You can't simply "spin up" a reverse geocoder on a cheap web server. You need to break down the problems your geocoder will solve and deploy a suite of geocoders to return the appropriate data for your application. We'll dig into types of reverse geocoding, finding data sources, keeping data updated, and determining how granular to make your results.

developer explaining geocoding

Reverse Geocoding Tutorial

For developers who want to roll their own geocoder, we'll show you how it's done, step-by-step. Using a world-wide dataset, you'll build a proof of concept to gain important intelligence from a pair of latitude and longitude coordinates. These ideas can be extended to any dataset to build a robust reverse geocoder.

atlas with coordinates

Open Geocoding Resources

A reverse geocoder can only be as good as the underlying data and tools. In particular, this section reviews the OpenStreetMap project's resources for map builders and other geo geeks. In addition, you'll find open source and public domain data, packages, and developer utilities used in robust, scalable geocoding projects from within the community. Finally, we list resources where you can learn more about geocoding and open data.

Need help with reverse geocoding?

At OpenCage we operate a highly-available, easy to use, affordable geocoding API built on open data, and used by hundreds of customers around the world. Learn more.