Biome vs Qlty (formerly Code Climate Quality)
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 $20 per contributor/month (Pro; Enterprise $30)
Free tierWhat drives the bill
The metric that actually scales your invoice.
Free and open source. You pay in engineering time and CI minutes.
Priced per contributor. Free for K-12 and universities, 10% off for registered non-profits.
Free tier
Everything, self-hosted
Free plan with unlimited contributors, 1,000 analysis minutes and 100 AI autofixes a month.
Open source
MIT
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Widely used
Biome / OSS community · since 2023
Established
Qlty Software (spun out of Code Climate) · since 2011
Strengths
- 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.
- Maintainability grading is easy to communicate to non-engineers.
- Coverage and quality tracked together in one PR check.
- Free for open source.
Limitations
- 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.
- Letter grades oversimplify and can drive the wrong behaviour.
- The Code Climate to Qlty transition means older documentation, URLs and integration guides still say Code Climate.
- Velocity, the companion engineering-metrics product, was sunset — do not buy expecting it.
Best for
New JavaScript projects and teams frustrated by lint performance.
Teams that want a simple maintainability signal in pull requests.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.