Release Pillow 12.3.0 on July 1, 2026

## Main release Released quarterly on January 2nd, April 1st, July 1st and October 15th. * [ ] Open a release ticket e.g. https://github.com/python-pillow/Pillow/issues/3154 * [ ] Develop and prepare release in `main` branch. * [ ] Add release notes e.g. https://github.com/python-pillow/Pillow/pull/8885 * [ ] Check [GitHub Actions](https://github.com/python-pillow/Pillow/actions) to confirm passing tests in `main` branch. * [ ] Check that all the wheel builds pass the tests in the [GitHub Actions "Wheels" workflow](https://github.com/python-pillow/Pillow/actions/workflows/wheels.yml) jobs by manually triggering them. * [ ] In compliance with [PEP 440](https://peps.python.org/pep-0440/), update version identifier in `src/PIL/_version.py` * [ ] Run pre-release check via `make release-test` in a freshly cloned repo. * [ ] Create branch and tag for release e.g.: ```bash git branch 12.3.x git tag 12.3.0 git push --tags ``` * [ ] Check the [GitHub Actions "Wheels" workflow](https://github.com/python-pillow/Pillow/actions/workflows/wheels.yml) has passed, including the "Upload release to PyPI" job. This will have been triggered by the new tag. * [ ] Publish the [release on GitHub](https://github.com/python-pillow/Pillow/releases). * [ ] In compliance with [PEP 440](https://peps.python.org/pep-0440/), increment and append `.dev0` to version identifier in `src/PIL/_version.py` and then: ```bash git push --all ``` ## Publicize release * [ ] Announce release availability via [Mastodon](https://fosstodon.org/@pillow) e.g. https://fosstodon.org/@pillow/110639450470725321 ## Documentation * [ ] Make sure the [default version for Read the Docs](https://pillow.readthedocs.io/en/stable/) is up-to-date with the release changes ## Docker images * [ ] Update Pillow in the Docker Images repository ```bash git clone https://github.com/python-pillow/docker-images cd docker-images ./update-pillow-tag.sh 12.3.0 ```