Python 3.14 Lands A New Interpreter With 3~30% Faster Python Code

Written by Michael Larabel in Programming on 10 February 2025 at 09:02 AM EST. 23 Comments

Merged last week for Python 3.14 is a new tail-call intepreter that aims to offer significantly better performance with around 10% faster performance in PyPerformance or around a 40% speed-up in Python-heavy benchmarks. This tail-call interpeter can even outperform the current Python JIT compiler but for maximum performance benefits Python should be built with Profile Guided Optimizations (PGO).

The new documentation on this newly-landed tail-call interpreter explains:

"A new type of interpreter based on tail calls has been added to CPython. For certain newer compilers, this interpreter provides significantly better performance. Preliminary numbers on our machines suggest anywhere from -3% to 30% faster Python code, and a geometric mean of 9-15% faster on pyperformance depending on platform and architecture.

This interpreter currently only works with Clang 19 and newer on x86-64 and AArch64 architectures. However, we expect that a future release of GCC will support this as well.

This feature is opt-in for now. We highly recommend enabling profile-guided optimization with the new interpreter as it is the only configuration we have tested and can validate its improved performance. For further information on how to build Python, see --with-tail-call-interp."

Exciting and I plan to run some benchmarks myself of this exciting Python 3.14 addition.

More background information on this new Python 3.14 interpreter via this GitHub ticket.

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The Python 3.14 schedule has alpha releases continuing through April, beta releases from May through July, release candidates in July and August, and hopefully shipping Python 3.14.0 in early October.