Geolocation - Wikipedia
From Web Browser:
As of Chrome 50, the Geolocation API only works on secure contexts (HTTPS). If your site is hosted on a non-secure origin (such as HTTP), any requests for the user's location no longer function.
From Web Server:
"The Google Maps Geolocation (REST web service) API returns a location and accuracy radius based on information about cell towers and WiFi nodes that the mobile client can detect.
You must specify a key in your request, included as the value of a key parameter. A key is your application's API key. This key identifies your application for purposes of quota management. Learn how to get a key."
"a public HTTP API for software developers to search the geolocation of IP addresses. It uses a database of IP addresses that are associated to cities along with other relevant information like time zone, latitude and longitude. You're allowed up to 10,000 queries per hour by default."
open source @ GitHub (GoLang)
fiorix/freegeoip: IP geolocation web server