Send a WHOIS request and get the information about a domain

Type in a domain name or a IP to send a WHOIS request and get more information about them:

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What is a WHOIS request?

The function of the WHOIS (“who is”) goes back to the predecessor of the Internet, the APRANET. In the APRANET, each connection point had a list of known hosts. This file still exist in modern operating systems, and is typical called “hosts”. This primary links a DNS hostname to a specific IP. With this it is possible to link any name you like to an IP address. On default, it links the hostname “localhost” to the loopback address of the interface, which is in most cases “”.

As the internet grew, indexing of domain names must be done by a central agency, because no typical user has the time to manage and refresh steadily this list. Nevertheless, the service must be spread over many locations to reach a load-balance and a very fast DNS lookup everywhere at the world. This management is done by agencies, called NIC’s (Network information center). If you call a DNS name, for example “” by a webbrowser, your operating system, respective network driver, ask the DNS servers of Verisign (manager of com domains) about the IP record of the domain. Then, it sends a request to the IP and download the website. On the same scheme provide the NICs the information about domain.

Which data do you find in WHOIS requests?

This depend strong at the network information center. Most domain reseller offer guard services. This is not available in each lands, because the typical government of many lands try to control his residents and forbid guard services. This is not an indicator of a scam! The most important domains are *.to-domains. This is the TLD of the Kingdom of Tonga. Tonga don’t give the information about a domain registrant to other ones! They cost a lot, but that is why many oldschool warez websites like torrent pages use .to-domains. Type in any domain or IP address of your choice and test which data to you find.

How to send a WHOIS request?

WHOIS is defined in the document RFC 3912. The WHOIS server wait at TCP port 43 and communicate only per plain text. For Windows is the shell tool Telnet good, but this is since Vista not anymore installed in a default installation. For Linux is the netcat recommend software, which is mostly installed already by default. Simple connect to the WHOIS server of the TLD of the domain, for example to for co-domains. Send the domain name about the stream, the server answer and close the connection. Because this is a very often used service, many servers close the connection after around three seconds without input to save resources. This form connect to the WHOIS server, send the domain and write the output to the text area.