Python 3.13 Release Notes 2025 Jun 2026

The Python development team would like to thank all contributors, users, and supporters for their help in making Python 3.13 a reality.

The ( --disable-gil ) is now a stable compile-time option. For CPU-bound multi-threaded workloads, threads can run truly in parallel on separate cores. Caveats: some C extensions need recompilation, and single-threaded performance drops ~5–10%. The default build still uses the GIL.

Python 3.13 is a significant release that brings many exciting improvements and features to the Python ecosystem. We hope you enjoy using it and exploring the many possibilities it offers.

Python continues its trend of making debugging friendlier.

This is the headline feature. Python 3.13 offers an experimental build mode called , which disables the Global Interpreter Lock (GIL).