Address geocoder available via the U.S. Census

The Census Geocoder is an address look-up tool that converts your address to an approximate coordinate (latitude/longitude) and returns information about the address range that includes the address and the census geography the address is within. The geocoder is available as a web interface and as an API (Representational State Transfer – REST – web-based service).

The tool allows you to look-up a single address or batch submit up to 1,000 addresses at a time.

https://www.census.gov/geo/maps-data/data/geocoder.html