26.1a1

This is a preview of the Black stable style for 2026 (#4892). Please test it and
share your feedback!

The following formatting changes are included:

• always_one_newline_after_import: Always force one blank line after import
  statements, except when the line after the import is a comment or an import statement
  (#4489)
• fix_fmt_skip_in_one_liners: Fix # fmt: skip behavior on one-liner declarations,
  such as def foo(): return "mock" # fmt: skip, where previously the declaration would
  have been incorrectly collapsed (#4800)
• fix_module_docstring_detection: Fix module docstrings being treated as normal
  strings if preceded by comments (#4764)
• fix_type_expansion_split: Fix type expansions split in generic functions (#4777)
• multiline_string_handling: Make expressions involving multiline strings more compact
  (#1879)
• normalize_cr_newlines: Add \r style newlines to the potential newlines to
  normalize file newlines both from and to (#4710)
• remove_parens_around_except_types: Remove parentheses around multiple exception
  types in except and except* without as. See PEP 758 for details (#4720)
• remove_parens_from_assignment_lhs: Remove unnecessary parentheses from the left-hand
  side of assignments while preserving magic trailing commas and intentional multiline
  formatting (#4865)
• standardize_type_comments: Format type comments which have zero or more spaces
  between # and type: or between type: and value to # type: (value) (#4645)
• Regenerated the _width_table.py and added tests for the Khmer language (#4253)

25.12.0

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!

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)

25.11.0

Highlights

• Enable base 3.14 support (#4804)
• Add support for the new Python 3.14 t-string syntax introduced by PEP 750 (#4805)

Stable style

• Fix bug where comments between # fmt: off and # fmt: on were reformatted (#4811)
• Comments containing fmt directives now preserve their exact formatting instead of
  being normalized (#4811)

Preview style

• Move multiline_string_handling from --unstable to --preview (#4760)
• Fix bug where module docstrings would be treated as normal strings if preceded by
  comments (#4764)
• Fix bug where python 3.12 generics syntax split line happens weirdly (#4777)
• Standardize type comments to form # type: <value> (#4645)
• Fix fix_fmt_skip_in_one_liners preview feature to respect # fmt: skip for compound
  statements with semicolon-separated bodies (#4800)

Configuration

• Add no_cache option to control caching behavior. (#4803)

Packaging

• Releases now include arm64 Linux binaries (#4773)

Output

• Write unchanged content to stdout when excluding formatting from stdin using pipes
  (#4610)

Blackd

• Implemented BlackDClient. This simple python client allows to easily send formatting
  requests to blackd (#4774)

Integrations

• Enable 3.14 base CI (#4804)
• Enhance GitHub Action psf/black to support the required-version major-version-only
  "stability" format when using pyproject.toml (#4770)
• Improve error message for vim plugin users. It now handles independently vim version
• Vim: Warn on unsupported Vim and Python versions independently (#4772)
• Vim: Print the import paths when importing black fails (#4675)
• Vim: Fix handling of virtualenvs that have a different Python version (#4675)

25.9.0

Highlights

• Remove support for pre-python 3.7 await/async as soft keywords/variable names
  (#4676)

Stable style

• Fix crash while formatting a long del statement containing tuples (#4628)
• Fix crash while formatting expressions using the walrus operator in complex with
  statements (#4630)
• Handle # fmt: skip followed by a comment at the end of file (#4635)
• Fix crash when a tuple appears in the as clause of a with statement (#4634)
• Fix crash when tuple is used as a context manager inside a with statement (#4646)
• Fix crash when formatting a \ followed by a \r followed by a comment (#4663)
• Fix crash on a \\r\n (#4673)
• Fix crash on await ... (where ... is a literal Ellipsis) (#4676)
• Fix crash on parenthesized expression inside a type parameter bound (#4684)
• Fix crash when using line ranges excluding indented single line decorated items
  (#4670)

Preview style

• Fix a bug where one-liner functions/conditionals marked with # fmt: skip would still
  be formatted (#4552)
• Improve multiline_string_handling with ternaries and dictionaries (#4657)
• Fix a bug where string_processing would not split f-strings directly after
  expressions (#4680)
• Wrap the in clause of comprehensions across lines if necessary (#4699)
• Remove parentheses around multiple exception types in except and except* without
  as. (#4720)
• Add \r style newlines to the potential newlines to normalize file newlines both from
  and to (#4710)

Parser

• Rewrite tokenizer to improve performance and compliance (#4536)
• Fix bug where certain unusual expressions (e.g., lambdas) were not accepted in type
  parameter bounds and defaults. (#4602)

Performance

• Avoid using an extra process when running with only one worker (#4734)

Integrations

• Fix the version check in the vim file to reject Python 3.8 (#4567)
• Enhance GitHub Action psf/black to read Black version from an additional section in
  pyproject.toml: [project.dependency-groups] (#4606)
• Build gallery docker image with python3-slim and reduce image size (#4686)

Documentation

• Add FAQ entry for windows emoji not displaying (#4714)

25.1.0

Highlights

This release introduces the new 2025 stable style (#4558), stabilizing
the following changes:

• Normalize casing of Unicode escape characters in strings to lowercase (#2916)
• Fix inconsistencies in whether certain strings are detected as docstrings (#4095)
• Consistently add trailing commas to typed function parameters (#4164)
• Remove redundant parentheses in if guards for case blocks (#4214)
• Add parentheses to if clauses in case blocks when the line is too long (#4269)
• Whitespace before # fmt: skip comments is no longer normalized (#4146)
• Fix line length computation for certain expressions that involve the power operator (#4154)
• Check if there is a newline before the terminating quotes of a docstring (#4185)
• Fix type annotation spacing between * and more complex type variable tuple (#4440)

The following changes were not in any previous release:

• Remove parentheses around sole list items (#4312)
• Generic function definitions are now formatted more elegantly: parameters are
  split over multiple lines first instead of type parameter definitions (#4553)

Stable style

• Fix formatting cells in IPython notebooks with magic methods and starting or trailing
  empty lines (#4484)
• Fix crash when formatting with statements containing tuple generators/unpacking
  (#4538)

Preview style

• Fix/remove string merging changing f-string quotes on f-strings with internal quotes
  (#4498)
• Collapse multiple empty lines after an import into one (#4489)
• Prevent string_processing and wrap_long_dict_values_in_parens from removing
  parentheses around long dictionary values (#4377)
• Move wrap_long_dict_values_in_parens from the unstable to preview style (#4561)

Packaging

• Store license identifier inside the License-Expression metadata field, see
  PEP 639. (#4479)

Performance

• Speed up the is_fstring_start function in Black's tokenizer (#4541)

Integrations

• If using stdin with --stdin-filename set to a force excluded path, stdin won't be
  formatted. (#4539)

24.10.0

24.10.0

Highlights

• Black is now officially tested with Python 3.13 and provides Python 3.13
  mypyc-compiled wheels. (#4436) (#4449)
• Black will issue an error when used with Python 3.12.5, due to an upstream memory
  safety issue in Python 3.12.5 that can cause Black's AST safety checks to fail. Please
  use Python 3.12.6 or Python 3.12.4 instead. (#4447)
• Black no longer supports running with Python 3.8 (#4452)

Stable style

• Fix crashes involving comments in parenthesised return types or X | Y style unions.
  (#4453)
• Fix skipping Jupyter cells with unknown %% magic (#4462)

Preview style

• Fix type annotation spacing between * and more complex type variable tuple (i.e. def fn(*args: *tuple[*Ts, T]) -> None: pass) (#4440)

Caching

• Fix bug where the cache was shared between runs with and without --unstable (#4466)

Packaging

• Upgrade version of mypyc used to 1.12 beta (#4450) (#4449)
• blackd now requires a newer version of aiohttp. (#4451)

Output

• Added Python target version information on parse error (#4378)
• Add information about Black version to internal error messages (#4457)

24.8.0

Stable style

• Fix crash when # fmt: off is used before a closing parenthesis or bracket. (#4363)

Packaging

• Packaging metadata updated: docs are explictly linked, the issue tracker is now also
  linked. This improves the PyPI listing for Black. (#4345)

Parser

• Fix regression where Black failed to parse a multiline f-string containing another
  multiline string (#4339)
• Fix regression where Black failed to parse an escaped single quote inside an f-string
  (#4401)
• Fix bug with Black incorrectly parsing empty lines with a backslash (#4343)
• Fix bugs with Black's tokenizer not handling \{ inside f-strings very well (#4422)
• Fix incorrect line numbers in the tokenizer for certain tokens within f-strings
  (#4423)

Performance

• Improve performance when a large directory is listed in .gitignore (#4415)

Blackd

• Fix blackd (and all extras installs) for docker container (#4357)

24.4.2

This is a bugfix release to fix two regressions in the new f-string parser introduced in
24.4.1.

Parser

• Fix regression where certain complex f-strings failed to parse (#4332)

Performance

• Fix bad performance on certain complex string literals (#4331)

24.4.1

24.4.1

Highlights

• Add support for the new Python 3.12 f-string syntax introduced by PEP 701 (#3822)

Stable style

• Fix crash involving indented dummy functions containing newlines (#4318)

Parser

• Add support for type parameter defaults, a new syntactic feature added to Python 3.13
  by PEP 696 (#4327)

Integrations

• Github Action now works even when git archive is skipped (#4313)