Python 3.13 includes an (copy-and-patch JIT) that can significantly speed up certain CPU-bound loops and function calls. The JIT is disabled by default but can be enabled via a build flag. Early benchmarks show 5–25% speedups on numeric and repetitive workloads.

Throughout 2025, major libraries (like NumPy and SciPy) have been working toward compatibility, but some C-extensions may still re-enable the GIL for safety. 2. A First Look at the JIT Compiler

Below is a about the Python 3.13 stable release, written as if it were released in October 2025, based on known plans and proposed features up to 2023.

Python can finally achieve true multi-core parallelism for CPU-bound tasks.