How to migrate from Flake8 and Black to Ruff?

Start by installing Ruff via pip and configuring it in `pyproject.toml` to match your existing rules. Use `ruff check` and `ruff format` as drop-in replacements, and enable `--fix` for automatic corrections during migration.

Ruff vs pylint: which should I use?

Ruff is faster and unifies linting with formatting, but pylint offers more in-depth static analysis and customization. Choose Ruff for speed and simplicity, or pylint for thorough, rule-heavy inspection.

Does Ruff work with type checkers like mypy?

No, Ruff does not perform static type checking; it focuses on linting and formatting. You should run mypy or similar tools alongside Ruff for comprehensive type analysis.

How to set up Ruff in VS Code?

Install the first-party Ruff extension from the marketplace, and it will automatically use your project's `pyproject.toml` configuration for real-time linting and formatting as you code.

Can Ruff fix all style violations automatically?

Ruff supports automatic fixes for many rules, but not all—check the `fixable` setting in configuration. Use `ruff check --fix` to apply fixes where possible, and manually address unfixable issues.

Is Ruff good for large monorepos?

Yes, Ruff's built-in caching and hierarchical configuration make it monorepo-friendly, allowing per-directory settings and fast incremental analysis across many files.

ruff — Fast Python Linter & Formatter

What is ruff?

Ruff is an extremely fast Python linter and code formatter written in Rust. It combines the functionality of multiple standalone tools like Flake8, Black, and isort into a single, high-performance package, solving the problem of slow, fragmented Python tooling by offering a unified and speedy alternative.

Target Audience

Python developers and teams working on projects of any size, especially those with large codebases or who prioritize fast CI/CD pipelines and developer tooling performance.

Value Proposition

Developers choose Ruff for its unmatched speed, which is 10-100x faster than traditional tools, and its ability to replace a dozen+ linters and formatters with one tool, simplifying configuration and improving workflow efficiency.

Overview

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

Use Cases

Best For

Speeding up linting and formatting in large Python monorepos
Replacing multiple fragmented tools (Flake8, Black, isort) with a single unified linter/formatter
Integrating fast static analysis into pre-commit hooks or CI/CD pipelines
Enforcing code quality with extensive, configurable rule sets across teams
Improving developer experience with near-instantaneous feedback in editors
Modernizing Python project tooling with `pyproject.toml`-based configuration

Not Ideal For

Projects requiring integrated static type checking (e.g., mypy) within the same tool, as Ruff focuses on linting and formatting only.
Teams heavily invested in custom or niche Flake8 plugins not yet re-implemented (e.g., flake8-bandit support is incomplete per the README).
Environments where tooling must be pure Python for compliance or auditability, since Ruff is written in Rust.
Organizations preferring gradual, piecemeal adoption of tools over replacing an entire linting/formatting stack at once.

Pros & Cons

Pros

Blazing Fast Performance

Ruff is 10-100x faster than Flake8 and Black, as evidenced by benchmarks linting the CPython codebase from scratch in seconds, drastically reducing CI times.

Unified Toolchain

It replaces multiple standalone tools like Flake8, isort, and Black with a single `ruff` command, simplifying dependencies and configuration in `pyproject.toml`.

Extensive Rule Coverage

With over 900 built-in rules, including native re-implementations of popular Flake8 plugins, Ruff offers comprehensive linting without external plugins.

Automatic Error Correction

Ruff provides fix support for issues like unused imports, enabling automatic error correction with the `--fix` flag to streamline refactoring.

Cons

Preview Mode Instability

New features and rules are gated behind an unstable preview mode that may change before stabilization, risking breakage in production workflows.

Incomplete Plugin Parity

While Ruff re-implements many Flake8 plugins, some like flake8-bandit are listed as in-progress, leaving gaps for security-focused linting.

Rapid Development Churn

As a fast-evolving project, frequent updates can introduce breaking changes, requiring careful version pinning and migration effort.

Open Source Alternative To

ruff is an open-source alternative to the following products:

F

Flake8

Flake8 is a Python linting tool that combines PyFlakes, pycodestyle, and McCabe complexity checker to enforce code quality and style consistency.

p

pyupgrade

pyupgrade is a tool that automatically upgrades Python syntax to newer versions, helping modernize code by applying language features from newer Python releases.

p

pydocstyle

pydocstyle is a static analysis tool for Python that checks compliance with PEP 257 docstring conventions and style guidelines.

i

isort

isort is a Python utility/library that sorts imports alphabetically and automatically separates them into sections and by type.

B

Black

Black is an uncompromising Python code formatter that automatically reformats code to comply with its style guidelines.

a

autoflake

autoflake is a Python command-line tool that removes unused imports and variables from Python code to help maintain clean and efficient codebases. It is often used as a pre-commit hook or in CI pipelines.

ruff

What is ruff?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Open Source Alternative To

Frequently Asked Questions

Related Projects

Found a gem we're missing?

ruff

What is ruff?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Open Source Alternative To

Frequently Asked Questions

Related Projects

Found a gem we're missing?