README

Ruff








Docs | Playground

An extremely fast Python linter and code formatter, written in Rust.


  
    
    
    
  



  Linting the CPython codebase from scratch.


- ⚡️ 10-100x faster than existing linters (like Flake8) and formatters (like Black)
- 🐍 Installable via pip
- 🛠️ pyproject.toml support
- 🤝 Python 3.15 compatibility
- ⚖️ Drop-in parity with Flake8, isort, and Black
- 📦 Built-in caching, to avoid re-analyzing unchanged files
- 🔧 Fix support, for automatic error correction (e.g., automatically remove unused imports)
- 📏 Over 900 built-in rules, with native re-implementations
    of popular Flake8 plugins, like flake8-bugbear
- ⌨️ First-party editor integrations for VS Code and more
- 🌎 Monorepo-friendly, with hierarchical and cascading configuration

Ruff aims to be orders of magnitude faster than alternative tools while integrating more
functionality behind a single, common interface.

Ruff can be used to replace Flake8 (plus dozens of plugins),
Black, isort,
pydocstyle, pyupgrade,
autoflake, and more, all while executing tens or hundreds of
times faster than any individual tool.

Ruff is actively developed and used in major open-source projects like:

- Apache Airflow
- Apache Superset
- FastAPI
- Hugging Face
- Pandas
- SciPy

Ruff is backed by Astral, the creators of
uv and ty.

Read the launch
post, or the
original project
announcement.

 Testimonials

Sebastián Ramírez, creator
of FastAPI:

 Ruff is so fast that sometimes I add an intentional bug in the code just to confirm it's actually
 running and checking the code.

Nick Schrock, founder of Elementl,
co-creator of GraphQL:

 Why is Ruff a gamechanger? Primarily because it is nearly 1000x faster. Literally. Not a typo. On
 our largest module (dagster itself, 250k LOC) pylint takes about 2.5 minutes, parallelized across 4
 cores on my M1. Running ruff against our _entire_ codebase takes .4 seconds.

Bryan Van de Ven, co-creator
of Bokeh, original author
of Conda:

 Ruff is ~150-200x faster than flake8 on my machine, scanning the whole repo takes ~0.2s instead of
 ~20s. This is an enormous quality of life improvement for local dev. It's fast enough that I added
 it as an actual commit hook, which is terrific.

Timothy Crosley,
creator of isort:

 Just switched my first project to Ruff. Only one downside so far: it's so fast I couldn't believe
 it was working till I intentionally introduced some errors.

Tim Abbott, lead developer of Zulip (also here):

 This is just ridiculously fast... ruff is amazing.



 Table of Contents

For more, see the documentation.

1. Getting Started
1. Configuration
1. Rules
1. Contributing
1. Support
1. Acknowledgements
1. Show Your Support
1. License

 Getting Started

For more, see the documentation.

 Installation

Ruff is available as ruff on PyPI.

Invoke Ruff directly with uvx:

shell
uvx [email protected] check    Lint all files in the current directory.
uvx [email protected] format   Format all files in the current directory.


Or install Ruff 

Top issues

Discussions

Latest release

Release Notes

Released on 2026-11-05.

 Preview features

- \[flake8-logging-format\] Avoid behavior changes and syntax errors in fixes (G004) (27419)
- \[security\] Implement tarfile-ignore-zeros-true (28680)

 Bug fixes

- Accept a bare raise before a semicolon (29761)
- Allow match identifiers after a semicolon (29760)
- Fix panic on BOM-prefixed files in diagnostic renderer (30017)
- \[flake8-simplify\] Report collapsible elif clauses after a multi-statement if branch (SIM102) (29814)

 Rule changes

- Show more nonprinting characters in diagnostic fix diffs (30062)

 Performance

- Coale