How IP geolocation works — and why it can't find your house

A snip.tools guide · runs alongside the IP address lookup

Type an IP address into a lookup tool and it hands back a country, a region, often a city, sometimes a map pin. It feels like surveillance-grade precision — but it isn't, and understanding why is the difference between using this data well and trusting it too much. IP geolocation is inference, not measurement: nobody is reading GPS off the address. Here's what's actually happening. (To look up any address and see the fields described here, use our IP address lookup.)

What an IP address really is

An IP address is a routing identifier, not a location. Its job is to get packets to the right network — much like a postal sorting code gets mail to the right depot, not to a specific desk. The address itself encodes no geography. Everything a geolocation service tells you is the result of mapping that address to other records that happen to carry location hints. That mapping is maintained in large databases (MaxMind, IP2Location, IPinfo and others), and the quality of those databases is the entire game.

Where the location data comes from

Geolocation providers assemble their maps from several layers, each less precise than the last:

• Regional registry allocations. Five Regional Internet Registries (ARIN for North America, RIPE for Europe, APNIC for Asia-Pacific, LACNIC, AFRINIC) hand out blocks of addresses to ISPs and organisations. These public records reliably pin down the country and the owning network.
• ISP and routing data. The provider that owns a block often documents which addresses serve which cities or regions. Reverse-DNS hostnames sometimes embed airport or city codes that hint at a point of presence.
• Inference and crowd-sourced signals. The finer "city" guess often comes from correlating addresses against latency measurements, Wi-Fi positioning data, and observed user locations from apps that know both an IP and a real GPS fix. This is where most of the error lives.

Because the bottom layer is statistical, a provider may report a precise-looking city — even latitude and longitude — that is really just the centroid of a region. Several databases default unknown US locations to a point in Kansas, which is exactly why a famous farm there spent years being virtually raided by people whose IPs "resolved" to the geographic centre of the country.

Why it's city-level at best

Your ISP typically serves a whole metro area from a handful of facilities, and the address you're using was assigned from a pool covering many subscribers. The best the database can usually do is identify the ISP and the broad area it serves. Country accuracy is very high (95%+ in mature databases); city accuracy is far lower and degrades fast outside dense urban networks. Street-level accuracy from an IP alone is not possible — anything claiming it is either using a different signal (GPS, Wi-Fi) or guessing.

What throws geolocation off

• Mobile networks and CGNAT. Carriers route many subscribers through a few gateways, so a phone in one town can appear to be in the city where the carrier's gateway lives — sometimes hundreds of kilometres away.
• VPNs and proxies. These deliberately substitute the exit server's address, so the result reflects the VPN's data centre, not the user. (Some databases flag known VPN/hosting ranges as exactly that.)
• Corporate and satellite links. A company may route all offices through one headquarters egress; satellite internet can surface at a ground station far from the dish.
• Reassigned blocks. Address space is bought, sold and reallocated; a database that hasn't refreshed can place an address in its previous owner's country for weeks.

IPv4 versus IPv6

The same principles apply to both, but the data is more mature for IPv4 simply because it's been mapped for decades. IPv6 allocations are newer and sometimes more sparsely documented, so geolocation of an IPv6 address can be coarser — though because IPv6 blocks are often assigned more granularly, the network owner is usually just as identifiable.

The honest takeaway

IP geolocation is excellent for country-level decisions — currency, language, content licensing, fraud signals — and reasonable for "roughly which metro." It is not a way to find a specific person or address, and any product that treats it that way will be wrong often enough to matter. Treat it as a confident guess about the network and a rough guess about the place.

A note on how our tool does the lookup: unlike the in-browser tools on this site, an IP lookup needs a network query, so the address you enter is sent to our server, which relays the lookup and returns the result — we don't store it. To try it, the IP address lookup shows the network owner, registry and approximate location for any address; what is my IP shows your own. To see the registry records directly, the WHOIS lookup exposes the allocation data these databases are built on.