New in version 1.1.

Complementary to translations provided for Sphinx-generated messages such as navigation bars, Sphinx provides mechanisms facilitating document translations in itself. See the Options for internationalization for details on configuration.


Workflow visualization of translations in Sphinx. (The stick-figure is taken from an XKCD comic.)

Sphinx internationalization details

gettext [1] is an established standard for internationalization and localization. It naively maps messages in a program to a translated string. Sphinx uses these facilities to translate whole documents.

Initially project maintainers have to collect all translatable strings (also referred to as messages) to make them known to translators. Sphinx extracts these through invocation of sphinx-build -b gettext.

Every single element in the doctree will end up in a single message which results in lists being equally split into different chunks while large paragraphs will remain as coarsely-grained as they were in the original document. This grants seamless document updates while still providing a little bit of context for translators in free-text passages. It is the maintainer’s task to split up paragraphs which are too large as there is no sane automated way to do that.

After Sphinx successfully ran the MessageCatalogBuilder you will find a collection of .pot files in your output directory. These are catalog templates and contain messages in your original language only.

They can be delivered to translators which will transform them to .po files — so called message catalogs — containing a mapping from the original messages to foreign-language strings.

Gettext compiles them into a binary format known as binary catalogs through msgfmt for efficiency reasons. If you make these files discoverable with locale_dirs for your language, Sphinx will pick them up automatically.

An example: you have a document usage.rst in your Sphinx project. The gettext builder will put its messages into usage.pot. Imagine you have Spanish translations [2] on your hands in usage.po — for your builds to be translated you need to follow these instructions:

  • Compile your message catalog to a locale directory, say locale, so it ends up in ./locale/es/LC_MESSAGES/ in your source directory (where es is the language code for Spanish.)

    msgfmt "usage.po" -o "locale/es/LC_MESSAGES/"
  • Set locale_dirs to ["locale/"].

  • Set language to es (also possible via -D).

  • Run your desired build.

Translating with sphinx-intl

Quick guide

sphinx-intl is a useful tool to work with Sphinx translation flow. This section describe a easy way to translate with sphinx-intl.

  1. Install sphinx-intl by pip install sphinx-intl or easy_install sphinx-intl.

  2. Add configurations to your

    locale_dirs = ['locale/']   # path is example but recommended.
    gettext_compact = False     # optional.

    This case-study assumes that locale_dirs is set to ‘locale/’ and gettext_compact is set to False (the Sphinx document is already configured as such).

  3. Extract document’s translatable messages into pot files:

    $ make gettext

    As a result, many pot files are generated under _build/locale directory.

  4. Setup/Update your locale_dir:

    $ sphinx-intl update -p _build/locale -l de -l ja

    Done. You got these directories that contain po files:

    • ./locale/de/LC_MESSAGES/
    • ./locale/ja/LC_MESSAGES/
  5. Translate your po files under ./locale/<lang>/LC_MESSAGES/.

  6. make translated document.

    You need a language parameter in or you may also specify the parameter on the command line:

    $ make -e SPHINXOPTS="-D language='de'" html

Congratulations! You got the translated documentation in the _build/html directory.

New in version 1.3: sphinx-build that is invoked by make command will build po files into mo files.

If you are using 1.2.x or earlier, please invoke sphinx-intl build command before make command.


Translate po file under ./locale/de/LC_MESSAGES directory. The case of builders.po file for sphinx document:

# a5600c3d2e3d48fc8c261ea0284db79b
#: ../../builders.rst:4
msgid "Available builders"

Another case, msgid is multi-line text and contains reStructuredText syntax:

# 302558364e1d41c69b3277277e34b184
#: ../../builders.rst:9
msgid ""
"These are the built-in Sphinx builders. More builders can be added by "
":ref:`extensions <extensions>`."
msgstr ""

Please be careful not to break reST notation. Most po-editors will help you with that.

Update your po files by new pot files

If a document is updated, it is necessary to generate updated pot files and to apply differences to translated po files. In order to apply the updating difference of a pot file to po file, use the sphinx-intl update command.

$ sphinx-intl update -p _build/locale

Using Transifex service for team translation

Transifex is one of several services that allow collaborative translation via a web interface. It has a nifty Python-based command line client that makes it easy to fetch and push translations.

  1. Install transifex-client

    You need tx command to upload resources (pot files).

    $ pip install transifex-client
  2. Create your transifex account and create new project for your document

    Currently, transifex does not allow for a translation project to have more than one version of the document, so you’d better include a version number in your project name.

    For example:

    Project ID:sphinx-document-test_1_0
    Project URL:
  3. Create config files for tx command

    This process will create .tx/config in the current directory, as well as a ~/.transifexrc file that includes auth information.

    $ tx init
    Creating .tx folder...
    Transifex instance []:
    Please enter your transifex username: <transifex-username>
    Password: <transifex-password>
  4. Upload pot files to transifex service

    Register pot files to .tx/config file:

    $ cd /your/document/root
    $ sphinx-intl update-txconfig-resources --pot-dir _build/locale \
      --transifex-project-name sphinx-document-test_1_0

    and upload pot files:

    $ tx push -s
    Pushing translations for resource
    Pushing source file (locale/pot/builders.pot)
    Resource does not exist.  Creating...
  5. Forward the translation on transifex

  6. Pull translated po files and make translated html

    Get translated catalogs and build mo files (ex. for ‘de’):

    $ cd /your/document/root
    $ tx pull -l de
    Pulling translations for resource (...)
     -> de: locale/de/LC_MESSAGES/builders.po

    Invoke make html:

    $ make -e SPHINXOPTS="-D language='de'" html

That’s all!


Translating locally and on Transifex

If you want to push all language’s po files, you can be done by using tx push -t command. Watch out! This operation overwrites translations in transifex.

In other words, if you have updated each in the service and local po files, it would take much time and effort to integrate them.

Contributing to Sphinx reference translation

The recommended way for new contributors to translate Sphinx reference is to join the translation team on Transifex.

There is sphinx translation page for Sphinx-1.3 documentation.

  1. Login to transifex service.
  2. Go to sphinx translation page.
  3. Click Request language and fill form.
  4. Wait acceptance by transifex sphinx translation maintainers.
  5. (after acceptance) translate on transifex.


[1]See the GNU gettext utilities for details on that software suite.
[2]Because nobody expects the Spanish Inquisition!