Python 3.15 is expected to speed up some programs and simplifies handling immutable data. UTF-8 as standard requires testing.

This article is a summary of the official announcement. Confirmation date: 2026-10-15 (confirmation date of 00_seed.md).

In benchmarks comparing Python 3.15 and Python 3.14, Python 3.15 was found to be approximately 1.45 times faster overall.