IP geolocation
IP geolocation estimates where an IP address is used, based on registry data and network measurements. It is accurate to the country, less so to the city.
What IP geolocation is
An IP address carries no location inside it. Geolocation is an estimate built from several sources: the country where a block was registered, the ASN that announces it and where that network operates, reverse DNS names that embed city codes, latency measurements from known points, and data contributed by services that know where their users are. Providers combine these into a mapping from address ranges to country, region, city, coordinates, and time zone, and publish updates as blocks move.
How accurate it is
Country-level results are right the large majority of the time, because address blocks are registered and routed regionally. City-level results are much less certain. A provider may use one block across several cities, mobile carriers route traffic through a few gateways, and corporate networks exit through a headquarters in another country. The coordinates in a result are the center of the estimated area, never a street address. Treat a city as "probably within this region" and the coordinates as a map pin for the city, not for a building.
Errors cluster around newly transferred blocks, mobile and satellite ranges, VPN exits that were deliberately registered elsewhere, and small providers whose records are stale.
Why it matters
Websites use geolocation to pick a language and currency, to enforce licensing and legal restrictions, and as an input to fraud checks: a card issued in one country used from an address in another, or a login from a new country, triggers extra verification. For proxy and VPN users the location of the exit address is the location they appear to have, and the rest of the browser has to agree with it. A time zone or language that does not fit the geolocated country is the easiest mismatch to spot.
Our data
We use the DB-IP Lite city database, published monthly under a Creative Commons Attribution license, and refresh it when a new edition passes our checks. If our result for an address is wrong, the About page explains how to report it; corrections go to the database maintainer, since we do not edit the data ourselves.
How to check
IP lookup shows the country, region, city, coordinates, and time zone for any address, together with the network that announces it. The IP checker shows the same for your own connection, which is the fastest way to see where a proxy or VPN places you.
A common misconception
Different services disagree about the same address because they use different data. For a disputed location, the registry record and the ASN's operating region are the facts; the city is an inference.