Python 3.9.25 is now available
Change effective on 03 November 2025
Python 3.9.25 is now available for use by Python apps on Heroku.
In addition, we have updated the Python 3.9 major version alias in our buildpacks so that it resolves to Python 3.9.25 instead of 3.9.24.
We strongly recommend that you use a major version alias when specifying a Python version for your app instead of pinning to an exact patch version, so that your app receives the latest Python security updates each time you build it.
See Specifying a Python Version for details on how to configure the Python version for your app.
This is the last Python 3.9 patch update, since Python 3.9 has now reached end-of-life upstream. As previously announced, use of Python 3.9 on Heroku is deprecated and support for it will be removed from our buildpacks on 7th January 2026.