How far away is a website?

Every website runs on servers with IP addresses, and each IP address belongs to a network that is registered and routed from a physical place. IP geolocation databases map those addresses to an approximate city and coordinates. Knowing where a server is tells you how far your requests travel, which affects how fast the site responds, and it hints at who hosts the site and whether it uses a content delivery network (CDN).

Tool description

This tool shows the distance between you and a website or IP address on a map. Enter a domain, a full URL, or an IP address. For a domain, the tool looks up its IPv4 and IPv6 addresses over DNS, then finds the location of each address and of your own IP address. The map draws the shortest route over the Earth's surface from you to each server, and the tool shows the distance and the lowest ping that distance allows.

Features

  • Accepts domains, full URLs, and IPv4 or IPv6 addresses; the path, port, and query of a URL are ignored
  • Resolves the domain's A and AAAA records through Google Public DNS
  • Finds the city, region, country, and network (ASN organization) of every resolved IP address
  • Draws great-circle routes from your location to each server location; your location is green, servers are red
  • Groups IP addresses that share a location into one marker, and lists every address with its location, network, and distance
  • Shows the distance to the nearest server in kilometers or miles, and the theoretical minimum ping to it

How it works

  1. DNS lookup: a domain is resolved to its A (IPv4) and AAAA (IPv6) records through Google Public DNS (8.8.8.8 and 8.8.4.4). An IP address is used as is.
  2. IP geolocation: each address, and the IP address you connect from, is looked up in the MaxMind and DB-IP geolocation databases.
  3. Distance: the great-circle distance between you and each server is calculated with the haversine formula on a sphere with the Earth's mean radius (6,371 km).
  4. Minimum ping: light in optical fiber travels at about two thirds of its speed in a vacuum, roughly 200 km per millisecond. The theoretical minimum ping is the time a signal needs to cover the distance there and back at that speed.

When a domain resolves to servers in more than one place, the distance and minimum ping are shown for the nearest one.

Limitations

  • IP geolocation is approximate. Addresses are often placed in the city of the network's registered office or in the middle of a country, so the real server can be tens or hundreds of kilometers away.
  • Your location comes from your public IP address. With a VPN, proxy, or mobile network, it is the location of that exit point, which is also where your traffic really leaves for the website.
  • Large sites and CDNs such as Cloudflare use anycast: one IP address is announced from many data centers, and you reach the one nearest to you. The database knows only one location for that address, so the distance may not match the server that actually answers.
  • DNS answers can depend on the resolver's location. Your own device may get different IP addresses than Google Public DNS returns.
  • Real ping is always higher than the theoretical minimum, because cables don't follow the shortest route and routers and servers add delay.
  • Up to 10 IP addresses of a domain are located.