IP Geolocation API Documentation - ipinfo.io
ipinfo.io/developers
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Use the ipinfo.io IP lookup API to quickly and simply integrate IP geolocation into your script or website. Save yourself the hassle of setting up local GeoIP libraries and having to remember to regularly update the data.