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Whois is an intelligent — pure Ruby — WHOIS client and parser.

It provides a flexible and programmable API to query WHOIS servers and look up IP, TLD, and domain WHOIS information. It also offers command-line interface to run WHOIS queries from the console.

Whois was extracted from RoboWhois and RoboDomain, and it's now in use at DNSimple. It has been performing queries in production since July 2009.


  • Ability to lookup WHOIS record for IPv4, IPv6, TLDs, and ICANN new gTLDs
  • Ability to parse WHOIS responses
  • Flexible and extensible interface (e.g. You can define custom servers on the fly)
  • Object oriented design, featuring 10 different design patterns
  • Pure Ruby library, without any external dependency other than Ruby itself
  • Successfully tested against different Ruby implementations, including Ruby and JRuby


You can install the gem manually via RubyGems:

$ gem install whois

Or use Bundler and define it as a dependency in your Gemfile:

gem 'whois', '~> 4.0'


Install the newer version via RubyGems:

$ gem install whois

The CHANGELOG file contains a detailed list of all the changes, grouped by version.

This library is versioned using the rules of Semantic Versioning.

Getting Started

This section covers the essentials of the Whois library. For a more deep explanation visit the complete usage section or read the whois manual.

Querying a WHOIS

This is the simplest way to send a WHOIS request is using the #lookup method.

c =
# => #<Whois::Record>

The method returns a Whois::Record instance which essentially looks and behaves like a String but it's way more powerful than a string (see Consuming the Record).

You can print, compare and modify it exactly as a string.

c =
r = c.lookup("")

puts r
# the full whois record response
# ...
# ...

If you don't need to customize the Whois::Client, you can also use the Whois.whois shortcut (see Whois::Client shortcuts section for more information).

r = Whois.whois("")

puts r
# the full whois record response
# ...
# ...

Whois provides the ability to get WHOIS information for TLDs, domain names, IPv4 and IPv6 IP addresses. The client is smart enough to guess the best WHOIS server according to given query, send the request and return the response.

c =

# Domain WHOIS
# => #<Whois::Record ...>

# => #<Whois::Record ...>

# => #<Whois::Record ...>

# => #<Whois::Record ...>

Consuming the Record

Any WHOIS query returns a Whois::Record. This object looks like a String, but it's way more powerful.

The Whois::Record encapsulates a WHOIS record and provides the ability to parse the WHOIS response programmatically, by using an object oriented syntax. Yep, you're not dreaming: no more regular expressions!

r = Whois.whois("")
# => #<Whois::Record ...>

# => false
# => true

# => Fri Dec 10 00:00:00 +0100 1999

t = r.technical_contact
# => #<Whois::Record::Contact ...>
# => "TS7016-ITNIC"
# => "Technical Services"

r.nameservers.each do |nameserver|
  puts nameserver

This feature is made possible by the Whois::Record::Parser. Unfortunately, due to the lack of a global standard, each WHOIS server requires a specific parser. For this reason, the library doesn't currently support all existing WHOIS servers.

If you create a new parser, please consider releasing it to the public so that it can be included in a next version.

More Information