About this API
US Census Geocoder is the official geocoding service run by the U.S. Census Bureau. It takes a U.S. address — either as a single line or split into fields — or a pair of coordinates, and returns the matched, standardized address, geographic coordinates, and census geography identifiers: state, county, census tract and block, based on the Bureau's TIGER/Line layers. The locations endpoint returns just the match and coordinates, while the geographies endpoint also assigns the address to census areas. The service supports single-record requests and a batch mode for many addresses at once. Every request needs a benchmark parameter (e.g. Public_AR_Current), and requests that return geography also need a vintage parameter. This is a geocoder, not a statistics API — the demographic and economic data itself is served by the separate U.S. Census Bureau data API.
Frequently asked questions
Do I need an API key?
No — the geocoder is public and free. Single-address and batch requests need no registration or API key. The API key offered on the Census developer site is for the separate statistics data API, not the geocoder.
What data does this API return?
For a U.S. address (or a pair of coordinates) it returns the matched, standardized address, geographic coordinates and — via the geographies endpoint — census geography identifiers: state, county, tract and block, based on TIGER/Line layers, in JSON.
Can this API be called directly from a browser?
No — the service does not send an Access-Control-Allow-Origin header, so a browser blocks cross-origin calls. It has to be called server-side, which is why there is no live "Try it" button here.
Who runs this API?
The U.S. Census Bureau, an agency of the U.S. Department of Commerce. Documentation: census.gov.