Python 3.15.0a8

Release date: April 7, 2026

This is an early developer preview of Python 3.15

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a8, is the final planned alpha release.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2026-05-05) and, if necessary, may be modified or deleted up until the release candidate phase (2026-07-28). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

• PEP 810: Explicit lazy imports
• PEP 814: frozendict built-in type
• PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
• PEP 798: Unpacking in comprehensions with * and **
• PEP 686: Python now uses UTF-8 as the default encoding
• PEP 728: TypedDict with typed extra items
• PEP 747: Annotating type forms with TypeForm
• PEP 782: A new PyBytesWriter C API to create a Python bytes object
• The JIT compiler has been significantly upgraded, with 6-7% geometric mean performance improvement on x86-64 Linux over the standard interpreter, and 12-13% speedup on AArch64 macOS over the tail-calling interpreter
• The official Windows 64-bit binaries now use the tail-calling interpreter
• Improved error messages
• (Hey, fellow core team member, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.15 will be 3.15.0b1, currently scheduled for 2026-05-05.

More resources

• Online documentation
• PEP 790, 3.15 release schedule
• Report bugs at https://github.com/python/cpython/issues
• Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

Ahab stood before him, and was lightly unwinding some thirty or forty turns to form a preliminary hand-coil to toss overboard, when the old Manxman, who was intently eyeing both him and the line, made bold to speak.

“Sir, I mistrust it; this line looks far gone, long heat and wet have spoiled it.”

“’Twill hold, old gentleman. Long heat and wet, have they spoiled thee? Thou seem’st to hold. Or, truer perhaps, life holds thee; not thou it.”

Enjoy the new release

Thanks to all of the many volunteers who help make Python development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organisation contributions to the Python Software Foundation.

Full Changelog