Ruff vs Codacy

Free and open source

From $21 per user/month (indicative, Pro)

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

Per-developer pricing rather than lines of code, which suits small teams with large codebases.

Everything, self-hosted

Free for open-source projects and small teams.

Category standard

Astral · since 2022

Established

Codacy · since 2014

• 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.

• Per-developer pricing is cheaper than SonarQube for small teams on big repositories.
• Bundles quality and security scanning in one PR check.
• Very quick to set up — connect a repository and it works.

• 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.

• Wrapping open-source linters means analysis depth depends on those tools.
• Configuration across many languages becomes fiddly.
• Less established than SonarQube in enterprise procurement.

Every Python project.

Small and mid-sized teams wanting quality and security checks in PRs without running a server.