Ruff vs Biome

Free and open source

Free and open source

Free and open source. You pay in engineering time and CI minutes.

Free and open source. You pay in engineering time and CI minutes.

Everything, self-hosted

Everything, self-hosted

Category standard

Astral · since 2022

Widely used

Biome / OSS community · since 2023

• Replaces Flake8, isort, Black, pyupgrade and more with a single fast binary.
• Fast enough to run on every keystroke in the editor.
• Straightforward migration from existing Flake8 configurations.

• Dramatically faster than ESLint plus Prettier, which matters on pre-commit hooks.
• One binary and one config replaces two toolchains.
• Very good ESLint rule migration tooling.

• Not every niche Flake8 plugin rule has been ported.
• Type checking is a separate concern — you still need mypy or ty.
• Rapid release cadence occasionally changes behaviour.

• Rule coverage does not yet match ESLint's plugin ecosystem.
• No support for framework-specific plugin ecosystems at ESLint's depth.
• Young project, so expect churn.

Every Python project.

New JavaScript projects and teams frustrated by lint performance.