Python 3.14 release candidate 1

The Python Software Foundation recently announced the availability of Python 3.14 Release Candidate 1 (3.14.0rc1), marking the penultimate preview of the upcoming Python 3.14 series. The release is now live and available for download. With this milestone, Python 3.14 enters the release candidate phase. From this point forward, only reviewed code changes that constitute clear bug fixes will be considered before the final release. No changes to the Application Binary Interface (ABI) are expected, and the goal is to minimize further code modifications.

Python 3.14 release candidate 1 is go!

The second and final release candidate, Python 3.14.0rc2, is scheduled for Tuesday, August 26, 2025. The official release of Python 3.14.0 is slated for Tuesday, October 7, 2025.

Call to the Community

The Python team strongly encourages all third-party project maintainers to begin testing their packages and preparing for full Python 3.14 compatibility. Developers are advised to publish Python 3.14 wheels on PyPI to ensure readiness and help downstream projects test compatibility. Binary wheels built against 3.14.0rc1 will remain compatible with the final release.

It is important to note that Python 3.14.0rc1 is a preview release. While it is functionally close to the final version, it is not recommended for use in production environments.

Message to Core Developers

With the codebase effectively frozen, core developers are asked to shift focus toward documentation. Contributors are encouraged to:

• Ensure all changes are properly documented
• Update the “What’s New” section as needed
• Identify and remedy insufficient documentation across the release
   

Highlights of Python 3.14

Python 3.14 introduces a broad set of enhancements across performance, concurrency, and developer tooling. Notable new features include:

• PEP 779 - Official support for free-threaded Python
• PEP 649 - Deferred evaluation of type annotations
• PEP 750 - Introduction of t-strings (template string literals)
• PEP 734 - Inclusion of multiple interpreters in the standard library
• PEP 784 - New compression.zstd module with Zstandard support
• PEP 758 - Simplified syntax for except and except* blocks
• Syntax highlighting improvements in PyREPL
• Color output added to unittest, argparse, json, and calendar CLIs
• PEP 768 - External debugger interface with zero overhead
• Enhanced UUID module with support for versions 6-8 and faster generation of versions 3-5
• PEP 765 - Restriction on return, break, and continue inside finally blocks
• PEP 741 - New and improved C API configuration interface
• A new performance-optimized interpreter for modern compilers (opt-in, build-from-source only)
• Improved error messages and developer experience
• Built-in HMAC implementation based on formally verified HACL* code
• New CLI for inspecting async Python processes
• pdb now supports remote attachment to running Python processes
   

Developers are invited to explore the full list of changes in the What's New in Python 3.14 documentation.

Build and Installer Changes

Python 3.14 introduces notable changes to its distribution and packaging:

• PEP 761 - Discontinuation of PGP signatures in favor of Sigstore for verifying release artifacts
• Official macOS and Windows builds now ship with an experimental Just-in-Time (JIT) compiler
   

The Windows installer is transitioning to a new install manager, available via the Microsoft Store or direct download

The traditional installer will remain available through the 3.14 and 3.15 series. A JSON manifest listing all installable packages and checksums is provided, though it is not required for installation.

Deprecated and Removed Features

• Python 3.14 includes multiple deprecations and removals, including:
• Deprecated Python language features
• Deprecated or removed C API elements
• Overview of pending and active removals is available in the changelog
   

Fun Fact: Pi Approximation Day

The release of Python 3.14.0rc1 coincided with Pi Approximation Day on July 22nd, commemorating the classic fractional approximation of π. This Diophantine approximation has been known since antiquity, with Archimedes providing the earliest known proof of its accuracy. In Chinese mathematics, 22/7 and the more accurate 355/113 are known as Yuelü (“approximate ratio”) and Milü (“close ratio”), respectively.