How to Trace an IP Address to a Physical Address

An internet protocol address identifies a computer on the internet or another network. You can often make a general guess at the physical location corresponding to an IP address, but you usually can't find an IP address location down to the exact building without information from the service provider that issued the IP. This information usually isn't available without a court order or without going through other legal processes. Be wary of anyone who offers address data by IP lookup with more precision, since it could be an exaggeration or stolen data.

An IP address is a numerical address that identifies a computer or another device on a network. The most common types of IP addresses are IPv4 addresses, which are typically written as sets of decimal digits separated by periods, like 127.0.0.1. Some networks also use IPv6 addresses, a newer type of address with room for more systems on each network. They're usually written as sets of hexadecimal digits separated by periods, such as 0000:0000:0000:0000:0000:0000:0000:0001.

When you access a computer by its domain name, such as www.example.com, that's translated into an IP address through the internet's Domain Name System, a massive, multi-computer database mapping domain names to IP addresses. Specialized computers called routers, including home wireless routers, then work together to get data between online computers using their IP addresses.

IP addresses are assigned to specific organizations, including internet service providers, tech companies, universities and government agencies. This makes it possible to look up what organization owns a particular IP address in public databases often called WHOIS databases, although these databases won't say how the organization is using the IP address. In particular, they won't tell you what customer of an internet provider is using the IP address.

Most computers automatically log the IP addresses they communicate with. For example, if you access a website, normally the IP address of your computer or smart phone will be logged. Depending on how your network is set up, this may be a public IP address shared by multiple devices that use your firewall or router.

If you find yourself harassed by someone from a particular IP address, you can use a public database to find out what internet provider or company owns that IP address and contact that organization to file a complaint. If you think a crime has been committed, you're often best off contacting the police or another law enforcement agency such as the Federal Bureau of Investigation. If you think you've been wronged in a way that makes you wish to sue someone, you can contact a lawyer.

Internet providers will essentially never give out the names, addresses or other contact information without a warrant, subpoena or some other legal document. Law enforcement or a lawyer can obtain the identity of someone behind a particular IP so you can move forward with any legal case. Keep in mind that it's possible that someone's network was hacked or someone accessed an open Wi-Fi connection, so the person who is assigned a particular IP may not be responsible for any incident.

Some online tools will give out approximate locations for a particular IP address. This is possible because internet providers often assign particular ranges of IP addresses to customers in a particular region, since this makes routing data simpler.

Also keep in mind that, even if you do know a location associated with an IP address, that may change over time if the ISP reassigns IP addresses among its customers. Naturally, IP addresses assigned by mobile phone and internet providers can also physically move, just as cellphones aren't bound to one particular location.

Be wary of any organization that claims to have exact IP address location data, since it may be outdated, stolen or just wrong. In some cases, organizations will map imprecise locations to a particular point, implying they have more precision than they do.