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There is a new dockerized build environment, see Dockerized development.

Modifying the theme

The styles for this theme use SASS and a custom CSS framework called Wyrm. We use Webpack and node-sass to build the CSS. Webpack is used to watch for changes, rebuild the static assets, and rebuild the Sphinx demo documentation.


The installation of Node is outside the scope of this documentation. You will need Node version 10+ in order to make changes to this theme.

Set up your environment

  1. Install Sphinx and documentation build dependencies.

    $ pip install -e '.[dev]'
  2. Install Webpack, node-sass, and theme dependencies locally.

    $ npm install

Making changes

Changes to the theme can be compiled and tested with Webpack:

$ npm run dev

This script will do the following:

  1. Install and update any dependencies.

  2. Build the static CSS from SASS source files.

  3. Build the demo documentation.

  4. Watch for changes to the SASS files and documentation and rebuild everything on any detected changes.

Alternatively, if you don’t need to watch the files, the release build script can be used to test built assets:

$ npm run build

Dockerized development

If you have Docker available on your platform, you can get started building CSS and JS artifacts a bit faster and won’t have to worry about any of the setup spilling over into your general environment.

When building with Docker, we create an image containing the build dependencies. Some of these are quite outdated and therefore ideal to isolate a container. The image is tagged as sphinx_rtd_theme:latest.

Inside the running docker image, we mount the working copy of the repository, build the artifacts and finally observe that the artifacts have been built and left in your current git checkout.

Use the following steps:

# Builds an updated version of the docker image
$ docker-compose build

# Runs the development webserver
$ docker-compose run sphinx_rtd_theme dev

# If you want to copy stuff out of the Docker environment, run this make
# target or read the actual Makefile to see what is going on.
# We suggest running this command every time that you want to quickly build
# new CSS/JS assets
$ make docker-build-all

Every time you change the Node or Python requirements, you will need to rebuild images with docker-compose run sphinx_rtd_theme build. If you change SASS or JS, you will need to rebuild assets.


QA testing theme changes and pull requests is complex, due to backwards compatibility.

The following cases need to be tested with changes to CSS or JavaScript:

  • Multiple, modern browsers should be tested.

  • Multiple viewport sizes should be tested for changes. We support large, tablet, and mobile viewport sizes

  • We currently support only HTML5 writer.

  • Multiple major versions of Sphinx should be tested. We currently support Sphinx >=5.0

It’s easiest to test combinations of dependency versions using tox:

% tox -e py310-sphinx62

If the tests and build are successful, you can view the built documentation at the directory noted by Sphinx:

build succeeded, 10 warnings.

The HTML pages are in .tox/py310-sphinx62/tmp/html.
___________________________ summary ___________________________
  py310-sphinx62: commands succeeded
  congratulations :)

You can then open up this path with a series of browsers to test.

The best way to spot UI issues is to compare two or more builds. You can build multiple tox environments, and open both up for comparison:

% tox -e py310-sphinx62
% tox -e py310-sphinx53
% firefox .tox/py310-sphinx62/tmp/html/index.html
% firefox .tox/py310-sphinx53/tmp/html/index.html

You can also use a separate tox environment for building output to compare against. All of the tox environments have an additional postfix, -qa, to allow building the same environment twice, without overwriting any files. In this test scenario, you would build from a branch or tag before building the same tox environment for the pull request branch you are testing.

For example, to test against the tag 0.5.2:

% git checkout 0.5.2
% tox -e py310-sphinx53-qa
% git checkout feature/example-pull-request
% tox -e py310-sphinx53
% firefox .tox/py310-sphinx53-qa/tmp/html/index.html
% firefox .tox/py310-sphinx53/tmp/html/index.html

Currently, the most important environments to QA are:

  • py310-sphinx53

  • py310-sphinx62

  • py310-sphinx72

  • py310-sphinxlatest

  • py310-sphinxdev


Translations are managed using Transifex. You can join any of the existing language teams or request a new language is added to the project. For more information on our translation standards, see our docs on Internationalization

Periodically, core team should update the translation files outside our normal releases. Someone from the core team, with write access to Transifex, should run the following:

$ python update_translations

This will extract new messages, upload the messages to Transifex, and will update our local translation files. Changes can be checked in to a branch and put up for review.


In between releases, the package version specified will always be a alpha release, matching 1.1.1alpha1.

As pull requests are merged and the release impact changes, this version will incremented ahead of release. For example, if we merge a new feature pull request, we’d run bump2version minor to increment 1.1.1alpha1 to 1.2.0alpha1.

To put out a release for testing, we will upload a release candidate. We would run bump2version release to increment 1.2.0alpha1 to 1.2.0rc1.

After a testing period, the release candidate can become a full release. We would run bump2version release again to increment 1.2.0rc1 to 1.2.0.

After the release process below, we increment the version again, so that the development version – the version found in the repository – is always greater than the most recent release. We follow up with another pull request by running bump2version patch, which increments 1.2.0 to 1.2.1alpha1.

Releasing the theme

To release a new version of the theme, core team will take the following steps:

  1. Bump the version by running bump2version [major|minor|patch|dev]. This will automatically increase the correct part(s) of the version number, you do not need to specify the exact version number. We follow semantic versioning and PEP440 (with regards to alpha release and development versions). The version increment should reflect these releases and any potentially breaking changes.

  2. New versions are by default alpha releases. If this is a release candidate, run bump2version --allow-dirty release to update the release to an rc release. If this is a final release, run the command again.

  3. Update the changelog (docs/changelog.rst) with the version information.

  4. Run python update_translations to compile new translation files and update Transifex.

  5. Run npm install && npm run build to rebuild all the theme assets, notice that package-lock.json will be updated with a new package version. But take care that it isn’t also bumping versions of dependencies in ways that are risky to the release. If package-lock.json changes, you need to commit it to git and tag it together with your release.

  6. Commit these changes to a pull request.

  7. Merge the pull request after review.

  8. Check out master branch locally for tagging. Remember to pull from remote.

  9. Tag the release in git: git tag -s $NEW_VERSION.

  10. Push the tag to GitHub: git push --tags origin.

  11. Upload the package to PyPI:

    $ rm -rf dist/
    $ python sdist bdist_wheel
    $ twine upload --sign --identity dist/*
  12. Finally, open a new pull request updating the development release version to the next patch by running bump2version patch. Open a pull request with this change. See Versioning above for more details.