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Geographic Information Systems at Yale: Geocoding Resources

Geographic Information Systems at Yale University encompasses a range of spatial applications and services. GIS is used by many disciplines at Yale University.

Geocoding Resources


  • Do your data include latitude and longitude? If so, you might not need to geocode. Please learn how to map XY data with ArcGIS Pro or QGIS
    1. Please review how many decimal degrees you have in your latitude/longitude data. If you need accuracy and you have less than five decimals, perhaps you should use geocoding to increase accuracy.


  • Are your addresses sensitive data? If so, you definitely need to conduct the geocoding on your computer without using a web-based geocoder. Please review the Esri address locator or the Texas A&M Geocoder options. 


  • If you have less than 500,000 addresses to geocode, we can provide Esri credits to conduct the geocoding using the Yale ArcGIS Online platform. Please email a request for additional Esri credits to

U.S. or Global addresses

To geocode more than 500,000  U.S. or world addresses using ArcGIS Pro, you need an address locator. There are a few ways to obtain the address locator that covers your study area:

  1. Esri address locators
  • To get access to the data, please answer this form, and we will contact you to establish a workflow to make the data available. Data licenses are limited in number; therefore, we will provide access for the duration of your geocoding task. 
  1. Government or your own address locator
  • Inquire to the GIS department of the municipalities included in your study area. Hopefully, they already created an up-to-date address locator that can share with you.
  • If you have the street or address data, create your own address locator. Check out this guide to determine if that is a feasible option for you. 

U.S, Addresses: Texas A&M Geocoder by Dan Goldberg. Ph.D. (Previously USC Geocoder)

  • Texas A&M GeoServices have been supporting researchers with free credits to run geocoding for noncommercial research projects. The initial credit quota when you open an account includes a small number of credits. Contact their team and inquire if they would kindly increase your credit quota, explaining you are a researcher. This is based on their decision, therefore it is advisable to explain why it is relevant to get their support. 
    Make sure to read about their privacy, security and terms to determine if it is aligned with your project requirements. 

Geocoding of Street Addresses and Administrative Boundary Levels

Geocoding APIs

Geocoding Services and Software to Determine Coordinates and Uncertainties in Text-based Localities

Simply put, Geocoding is the process of assigning a set of coordinate pairs (combined to create points, lines or polygons) that describe the locality of some object or phenomenon. The most familiar form of geocoding is performed when you enter an address into Google Maps, MapQuest or other online street mapping platform, and a point on a map is returned to you. However, street addresses are not the only locality types that are subject to the geocoding process. Localities referring to various administrative boundary levels (state, district, province, postal code) and even localities with varying levels of specificity (directional offsets from known locations, distances along paths, etc...) can be geocoded and, importantly, qualified with some level of geometric uncertainty. In the research context, geocoding is generally done as a batch process, though it is generally an iterative one, requiring some manual quality control and fine-tuning for best results. The resources and tools listed here are those that I have found useful in various types of geocoding processes.


In general, these are searchable databases of toponyms (geographic placenames).