IP address lookup

What an IP lookup can tell you

Every public IP address is allocated to an organisation, and that allocation is a matter of public record. A lookup joins the address to the registry data and to a commercial geolocation database, returning the operator, the autonomous system, and an estimate of where the block is used.

Geolocation

Country, region and city are estimates derived from routing data, registry records and operator-published information. Country is reliable. City frequently is not — a residential connection may be attributed to the provider's regional hub tens of kilometres away, and mobile traffic often surfaces at whichever gateway the carrier routes through.

Coordinates

The latitude and longitude are a representative point for the whole address block — typically the centre of the city or region it serves, sometimes the operator's facility, occasionally the geographic centre of a country when nothing finer is known. They are reported here as plain numbers you can copy, and nothing on this page plots them, because a pin on a map implies a precision that does not exist. Two addresses on opposite sides of a city routinely share one coordinate pair.

Host name

The host name comes from the address's PTR record, published by whoever holds the address block rather than by whoever owns the domain. Most addresses have none, and that is normal rather than broken. Where one exists it is often the most human-readable clue available — dns.google says more than any city estimate. The reverse DNS lookup covers what PTR records are for, why mail servers insist on them, and how to get one set.

Network operator and ASN

The ASN is usually the most dependable field. It identifies the network that announces the address block to the rest of the internet, which tells you whether an address belongs to a residential provider, a hosting company, a corporate network or a VPN operator — a genuinely useful distinction when investigating traffic.

Practical uses

• Diagnosing routing. Confirm where a connection actually terminates when latency looks wrong.
• Verifying a VPN. Check that your traffic exits where you expect it to.
• Reviewing logs. Determine whether unexpected traffic came from a datacentre or a residential connection.
• Configuring firewalls. Identify the operator behind an address before allowing or blocking it.

How accurate is any of this?

Accuracy varies enormously by field, and treating all of them as equally reliable is the most common way to reach a wrong conclusion from a correct lookup.

The reason for the spread is that none of this is measured — it is looked up. Address ranges are allocated to organisations by regional internet registries, and those organisations declare, or fail to declare, where they use them. A geolocation database assembles registry records, operator declarations and inference into a best guess. The ASN and network operator come from registry data and are close to authoritative; the city is an inference layered on top of it.

When a lookup will be wrong, and it is not a bug

• Mobile connections. Traffic often surfaces at a regional gateway rather than near the handset, so a phone in one city routinely geolocates to another hundreds of kilometres away.
• VPNs and proxies. The result describes the exit server, which is the entire point of using one. If you are checking your own address and it looks foreign, that is the VPN working. The VPN detector reports whether an address looks like one — with an explicit "unknown" when the data does not support a verdict.
• Corporate networks. A company may route every office through one head-office connection, so a laptop in one country appears in another.
• Satellite and CGNAT providers. One address can be shared by thousands of subscribers spread across a whole country.
• Recently reassigned ranges. Registry allocations change hands, and databases take time to catch up. A range sold last month may still report its previous owner.

What it cannot tell you

It cannot identify a person, a household or a street address, and it cannot reliably distinguish individual users behind carrier-grade NAT, where thousands share one address. Treat every geolocation result as an estimate with real error bars, and never as evidence about an individual.

It also cannot tell you what is running at that address — for that, check which ports are reachable, what certificate it presents, or what reverse DNS name it claims. And it cannot tell you who owns the domain pointing at an address; that is a WHOIS lookup, which reads a different registry entirely.

To see your own address instead, use What is my IP, or check each protocol separately with the IPv4 and IPv6 checkers.