ISO 639

A Ruby gem that provides the ISO 639-2 and ISO 639-1 data sets along with some convenience methods for accessing different entries and entry fields. The data comes from the LOC ISO 639-2 UTF-8 data set.

The ISO 639-1 specification uses a two-letter code to identify a language and is often the recommended way to identify languages in computer applications. The ISO 639-1 specification covers most developed and widely used languages.

The ISO 639-2 (Wikipedia) specification uses a three-letter code, is used primarily in bibliography and terminology and covers many more languages than the ISO 639-1 specification.


To install from RubyGems:

gem install iso-639

To install with Bundler, add the following to your Gemfile:

gem 'iso-639'

Then run bundle install


require 'iso-639'

To find a language entry:

# by alpha-2 or alpha-3 code
# or
# by English name
# by French name

The class method searches across all fields and will match names in cases where a record has multiple names. This method always returns an array of 0 or more results. For example:"spanish")
# => [["spa", "", "es", "Spanish; Castilian", "espagnol; castillan"]]

Entries are arrays with convenience methods for accessing fields:

@entry = ISO_639.find("slo")
# => ["slo", "slk", "sk", "Slovak", "slovaque"]
# => "slo"
@entry.alpha3 # shortcut for #alpha3_bibliographic
# => "slo"
# => "slk"
# => "sk"
# => "Slovak"
# => "slovaque"

The full data set is available through the ISO_639::ISO_639_1 and ISO_639::ISO_639_2 constants.

Note on Patches/Pull Requests

  • Fork the project.
  • Make your feature addition or bug fix.
  • Add tests for it. This is important so I don't break it in a future version unintentionally.
  • Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
  • Send me a pull request. Bonus points for topic branches.

Copyright (c) 2010 William Melody. See LICENSE for details.