Free tools or API for IP address geolocation lookup, which enable you to track the visitor's location and ip information in real-time. Supported both IPv4 and IPv6
Free IP Geolocation API and Accurate IP Database provides country, city, zip code, ISP data in REST JSON and XML format from any IPv4 and IPv6 Address.
Locate website visitors for free using ipstack - a free, real-time IP address to location JSON API and database service supporting IPv4 and IPv6 lookup.