Python 2.7 EOL FAQ

Last updated May 03, 2023

Why is Python 2 being sunset?

Python 2 was superseded by Python 3 many years ago, and as such the upstream Python project officially ended support for Python 2 on January 1st, 2020, after several extensions to the sunset date. This means no new versions of Python 2 are being released upstream, so it no longer receives security or bug fixes.

What Heroku stack versions support Python 2?

Python 2 is only supported on Heroku’s oldest stack, Heroku-18, which reached end-of-life on April 30th, 2023.

What will happen to existing Python 2 apps on Heroku?

Existing Python 2.7 applications on Heroku will continue to run for the foreseeable future (unless impacted by issues unrelated to the Python version).

However:

  • Since Python 2 has not received security fixes since 2020, it contains several unfixed security vulnerabilities, and so customers are strongly encouraged to migrate to a newer Python version to keep their applications secure.
  • It is no longer possible to perform further builds (code deployments) of apps on Heroku-18, so Python 2 apps can no longer be updated until they are first upgraded to a newer Heroku stack (which will also require updating to Python 3). See the Heroku-18 End-of-Life FAQ for more details.

Will Python 2 apps still receive technical support?

End of life language versions fall outside of Heroku’s Support Policy, and so Python 2 applications are no longer eligible for technical support without first upgrading to a supported version of Python.

How do I migrate my application to Python 3?

See the upstream Python project’s guide to Porting Python 2 Code to Python 3.

Once your application has been made compatible with Python 3 locally, you will then need to ensure that Heroku builds your application using Python 3. See Specifying a Python Runtime and supported Python versions.

I’m not going to be able to migrate to Python 3, what are my options?

Python 2 contains several unfixed security vulnerabilities, and so customers are strongly encouraged to migrate to a newer Python version to keep their applications secure. However, if you are willing to accept this risk there are two ways you can continue to use Python 2:

  1. If your application does not need any further code changes/new deployments, you can continue using your existing Python 2 application even after the end-of-life of the Heroku-18 stack with no changes required (see the Heroku-18 End-of-Life FAQ for more details).
  2. However, if you wish to continue performing new code deployments one alternative would be to migrate to Heroku’s container stack instead, and use the legacy python:2.7 Docker images (note: these Docker images have not received security updates since 2020 either). See:

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