This feature is currently opt-in and requires installing a specific free-threaded binary. Developers should expect minor library incompatibilities as the open-source ecosystem updates its C extensions. ⚡ A Brand New JIT Compiler
import interpreters import math
Dead weight like telnetlib , cgi , and chunk are completely gone.
Python 3.13 continues the multi-year performance initiative started in version 3.11 by integrating an experimental Just-In-Time (JIT) compiler. It utilizes a copy-and-patch JIT design. python news today release 3.13 november 2025
This command scans your active environment and produces a full dependency tree, including transitive dependencies, their licenses, and known CVEs (via a local cache of the National Vulnerability Database).
It significantly accelerates execution speed for heavy numerical loops.
This feature uses a small on-device LLM (Mistral-7B distilled) that ships with Python 3.13 – optional, install via python -m ensure_explain . This feature is currently opt-in and requires installing
On a 16-core AMD EPYC server, a parallel prime-sieving workload runs 3.7x faster than the equivalent multiprocessing version, with 40% less memory overhead.
"Python 3.13 is what happens when a community decides that slow is a choice, not a destiny." – RealPython Editorial Team, November 2025
p: Point = "x": 10, "y": 20 p["y"] = 30 # OK p["x"] = 40 # Type error: "x" is read-only Python 3
The JIT is not yet as aggressive as PyPy’s tracing JIT, but it requires zero changes to your code. For the first time, CPython beats PyPy on several microbenchmarks (while staying far ahead on startup time).
, the Copy-and-Patch JIT compiler introduced as an experiment in Python 3.13 beta, is now enabled by default on x86-64 and ARM64 builds.
Misspelled variables spark instant, accurate correction ideas. 🧹 Deprecations and Removals