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

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

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  • Ability to lookup WHOIS record for IPv4, IPv6, TLDs, and ICANN new gTLDs
  • Ability to parse WHOIS responses (via the whois-parser library)
  • 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

Whois and Whois parser

Starting from version 4, WHOIS parser component is available in a separate repository called whois-parser, and released as a separate gem called whois-parser.

This repository contains the core whois library, that includes the WHOIS client, the server definitions and all the features required to perform WHOIS queries and obtain the WHOIS record.


  • Ruby >= 2.0.0

For older versions of Ruby, see the CHANGELOG.


You can install the gem manually:

gem install whois

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

gem 'whois'

To use the WHOIS parser component you need to install the whois-parser gem:

gem install whois-parser
gem 'whois-parser'

The whois-parser gem already depends on the whois gem. If you install whois-parser, whois will be installed as well and it will also be automatically required when you require 'whois-parser'.

If you are upgrading to 4.0, see

Getting Started

Note. This section covers only the essentials for getting started with the Whois library. The documentation provides a more accurate explanation including tutorials, more examples and technical details about the client/server/record/parser architecture.

Querying a WHOIS

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

Check out the following examples:

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

whois =
# => #<Whois::Record>

whois =
# => #<Whois::Record>

whois =
# => #<Whois::Record>

The query method is stateless. For this reason, you can safely re-use the same client instance for multiple queries.

whois =

If you just need a WHOIS response and you don't care about a full control of the WHOIS client, the Whois module provides an all-in-one method called Whois.whois. This is the simplest way to send a WHOIS request.

# => #<Whois::Record>

Did I mention you can even use blocks? do |w|

Consuming the Record

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

Whois::Record encapsulates a WHOIS record and provides the ability to parse the WHOIS response programmatically, when the whois-parser gem is installed and loaded.

require 'whois-parser'

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

parser = record.parser
# => #<Whois::Parser>

# => false
# => true

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

tech = parser.technical_contacts.first
# => #<Whois::Record::Contact>
# => "TS7016-ITNIC"
# => "Technical Services"

parser.nameservers.each do |nameserver|
  puts nameserver

This feature is made possible by the Whois record parsers. Unfortunately, due to the lack of a global standard, each WHOIS server requires a specific parser. For this reason, the library doesn't 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.


By default, each query run though the client has a timeout value of 5 seconds. If the execution exceeds the timeout limit, the client raises a Timeout::Error exception.

Of course, you can customize the timeout value setting a different value. If timeout is nil, the client will wait until the response is sent back from the server or the process is killed. Don't disable the timeout unless you really know what you are doing!

whois = => 10)
whois.timeout # => 10
whois.timeout = 5
whois.timeout # => 5



Whois was created and is maintained by Simone Carletti. Many improvements and bugfixes were contributed by the open source community.


Direct questions and discussions to Stack Overflow.

Pull requests are very welcome! Please include spec and/or feature coverage for every patch, and create a topic branch for every separate change you make.

Report issues or feature requests to GitHub Issues.

More Information


Whois uses Semantic Versioning 2.0.0


Copyright (c) 2009-2018 Simone Carletti. This is Free Software distributed under the MIT license.