An IP WHOIS Lookup determines ownership information of any IP address.


Search for IP WHOIS information using the IP WHOIS lookup tool for any allocated IP address. This tool works as a type of domain IP lookup to provide you with the IP address owner’s contact information. The results also show the regional Internet registry (RIR) who assigned the IP, the assigned owner, location, and abuse reporting details. With the tool, you can also see the number of IP addresses that are in the block assigned to the owner of the IP you search.

Use the IP WHOIS lookup tool to find information about an IP.

To run an Internet WHOIS lookup for IP addresses, enter the IP address into the space above. Click "Lookup" and the tool will run a WHOIS search for the IP. You'll receive ARIN WHOIS data as well as information on your Internet service provider and the owner of the address.

Using the IP WHOIS results

The WHOIS IP lookup tool is how you find out who an IP address belongs to. With the IP WHOIS results, you’ll be able to find out exactly who to contact should you need to reach the owner of a given IP address. You’ll also see information regarding the Internet service provider (ISP) that has been assigned to the IP address. You can find the same information for your own IP on the What Is My IP homepage.

If you are a victim of IP abuse or IP spamming, use the IP WHOIS results to contact the ISP and file a complaint. You can also use the non-abuse contact information. However, it’s recommended to contact the ISP first as the IP address’ owner may not actually be behind the abuse.

What does WHOIS stand for?

WHOIS does not stand for anything; rather, it’s meant to be read as “who is.” The phrase is capitalized because it is a query and response protocol used for querying databases that contain the registered users of IP addresses when in the context of the WHOIS IP address lookup. The WHOIS protocol is also used to query other types of databases that contain similar information regarding domain names.

Finding other IP information

Searching a WHOIS database of IP addresses works to find out who an IP address is registered to and provide other data when you already have an IP address. However, in some instances, you may need to first find an IP address from a domain in order to search it in the WHOIS lookup tool.

To find an IP address from a domain, look up the domain in the domain name system with the DNS lookup tool. To find a domain from an IP address, use a reverse IP address lookup, or reverse DNS lookup.

What are the Regional Internet Registries?

The Regional Internet Registries, or RIRs, are organizations that manage the allocation and registration of Internet number resources, such as IP addresses. They are divided across the world, with each registry providing coverage to a different region.

An RIR is needed because of the expansive nature of the Internet. Though there are many IPs available for use, there's not an unlimited amount. Therefore, the Regional Internet Registries establish guidelines to handle allocation after IPs are generated by the IANA.

Each RIR follows the same base policy and from there, each registry can govern in the way necessary for their region. They monitor the IP pool and protect the policies of the Internet for all users.

The 5 Regional Internet Registries

All five RIRs are united by participation in the collective Number Resource Organization (NRO). However, they also operate separately as follows: