Python 3.15.0 Alpha 1 released
Developers can now get a first look at Python 3.15. This early developer preview is the first step in making the 3.15 series and starts a seven-phase alpha testing process.
The goal of this phase is to make it easier for users to test new features and bug fixes, as well as improve the release process itself. But it's important to remember that big changes can happen before the beta phase starts in May 2026. For example, some features may be added, changed, or taken away.
Because this is an experimental version, it is not recommended for use in production environments because it is likely to have bugs or other problems. As development goes on, Python 3.15 is likely to get a number of new major features and changes.
One big change is the addition of a separate profiling package, as described in PEP 799. Also, Python will now use UTF-8 encoding by default, as PEP 686 says it should. The new PyBytesWriter C API, which is explained in PEP 782, has made it possible to make Python bytes objects even better by making them faster to create.
Error messages have also been improved, which makes it easier for users to find and fix problems that may come up. This document is still being worked on, so if a major feature is missing from the current list, core developers should contact Hugo to make sure it is included in future versions.
The next alpha release, 3.15.0a2, is set to come out on November 18, 2025. This is another step forward in the ongoing development of Python 3.15.
Python Insider: Python 3.15.0 alpha 1
