Python 3.14

Source: Astral Date: 2025-10-07 URL: https://astral.sh/blog/python-3.14

Summary

Python 3.14 stable ships; Astral’s coverage: Ruff v0.14.0 and uv v0.9.0 both add 3.14 support on release day. Key 3.14 features: t-strings (template strings that produce structured Template objects rather than plain strings), free-threaded Python (no-GIL) moves from experimental to officially supported (at ~10% single-threaded perf cost), and a Clang 19+ tail-call interpreter delivering 3-5% pyperformance gains. Python 3.9 reaches EOL; Ruff bumps its default target from 3.9 to 3.10.

Implications

Astral’s day-one 3.14 coverage is the ecosystem signal. When a new Python version lands and the fastest installer and linter both support it on release day, it sets a new expectation for toolchain vendors. The free-threaded Python graduation is the bigger story: GIL removal changes the threading model for all Python code, and Astral’s python-build-standalone already ships free-threaded builds. t-strings are the most interesting new syntax — structured interpolation enables safer SQL/HTML templating patterns, and Ruff will need rules to detect misuse (plain f-strings where t-strings were intended). Watch for t-string lint rules in the 0.14-0.15 range.