Ruff vs DeepSource
Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.
Entry price
Free and open source
Open sourceFrom $24 per user/month (Team, billed yearly)
Free tierWhat drives the bill
The metric that actually scales your invoice.
Free and open source. You pay in engineering time and CI minutes.
Team includes a $100 annual AI Review credit per user; Enterprise adds self-hosting and SSO on a quote.
Free tier
Everything, self-hosted
Free for public repositories, with 1,000 PR reviews a month; 14-day trial plus AI Review credits on paid plans.
Open source
MIT
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Category standard
Astral · since 2022
Established
DeepSource · since 2019
Strengths
- 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.
- Autofix commits remove the tedious half of acting on findings.
- Low false-positive rate keeps developers engaged with the tool.
- Cheap and quick to adopt.
Limitations
- 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.
- Narrower language coverage than SonarQube.
- Smaller vendor with less enterprise governance tooling.
- Autofix still needs review — it is not unattended.
Best for
Every Python project.
Teams that want static analysis developers do not resent.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.