# Black 25.12.0

- Product: Black (https://whatsnew.fyi/product/black)
- Vendor: Python Software Foundation
- Date: 2025-12-08
- Version: 25.12.0
- Original notes: https://github.com/psf/black/releases/tag/25.12.0
- Permalink: https://whatsnew.fyi/product/black/releases/25.12.0

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **removed** — Black no longer supports running with Python 3.9
- **fixed** — Fix bug where comments preceding # fmt: off/# fmt: on blocks were incorrectly removed, particularly affecting Jupytext's # %% [markdown] comments
- **fixed** — Fix crash when multiple # fmt: skip comments are used in a multi-part if-clause, on string literals, or on dictionary entries with long lines
- **fixed** — Fix possible crash when fmt: directives aren't on the top level
- **fixed** — Fix # fmt: skip skipping the line after instead of the line it's on
- **changed** — Remove unnecessary parentheses from the left-hand side of assignments while preserving magic trailing commas and intentional multiline formatting
- **fixed** — Fix fix_fmt_skip_in_one_liners crashing on with statements
- **fixed** — Fix fix_fmt_skip_in_one_liners crashing on annotated parameters
- **fixed** — Fix new lines being added after imports with # fmt: skip on them
- **added** — Releases now include arm64 Windows binaries and wheels
- **added** — Add output-file input to GitHub Action psf/black to write formatter output to a file for artifact capture and log cleanliness

Please test out the draft 2026 style in version 26.1a1! This style will be finalized in
the January release (26.1.0). Most of the changes in `--preview` will be in the 2026
stable style, but not all.
[Please share your feedback!](https://github.com/psf/black/issues/4042)

This release (25.12.0) will still produce the 2025 style.

###### Highlights

- Black no longer supports running with Python 3.9 (#4842)

###### Stable style

- Fix bug where comments preceding `# fmt: off`/`# fmt: on` blocks were incorrectly
  removed, particularly affecting Jupytext's `# %% [markdown]` comments (#4845)
- Fix crash when multiple `# fmt: skip` comments are used in a multi-part if-clause, on
  string literals, or on dictionary entries with long lines (#4872)
- Fix possible crash when `fmt: ` directives aren't on the top level (#4856)

###### Preview style

- Fix `fmt: skip` skipping the line after instead of the line it's on (#4855)
- Remove unnecessary parentheses from the left-hand side of assignments while preserving
  magic trailing commas and intentional multiline formatting (#4865)
- Fix `fix_fmt_skip_in_one_liners` crashing on `with` statements (#4853)
- Fix `fix_fmt_skip_in_one_liners` crashing on annotated parameters (#4854)
- Fix new lines being added after imports with `# fmt: skip` on them (#4894)

###### Packaging

- Releases now include arm64 Windows binaries and wheels (#4814)

###### Integrations

- Add `output-file` input to GitHub Action `psf/black` to write formatter output to a
  file for artifact capture and log cleanliness (#4824)