head to head · open source
Kestra vs Windmill
Kestra has 30,122 GitHub stars, 3,495 forks, 713 open issues and last shipped yesterday. Windmill has 18,360 stars, 1,136 forks, 852 open issues and last shipped yesterday. Kestra leads on adoption by 64% (30,122 vs 18,360 stars). Kestra is written in Java under Apache-2.0; Windmill is written in Rust under a custom or non-standard licence. Kestra has attracted 12% as many forks as stars, Windmill 6%. Kestra was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (ai-agents), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Kestra | Windmill | |
|---|---|---|
| GitHub stars | ★ 30K | ★ 18K |
| License | Apache-2.0 | Custom / other |
| Written in | Java | Rust |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 3.5K | ⑂ 1.1K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Kestra if
- You weight community size — 30K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Java
- You value the larger contributor base for long-term maintenance
pick Windmill if
- You want the Windmill feature set and don't need the biggest community
- You prefer the Custom / other license terms
- Your stack matches Rust
- You evaluated both and Windmill fits your workflow better
About Kestra
Open source orchestration platform for data, AI, and infrastructure workflows Click on the image to learn how to get started with Kestra in 3 minutes. 🌟 What is Kestra? Kestra is an open source, event driven orchestration platform for data, AI, and infrastructure workflows. It unifies scheduled and event driven automation behind a declarative, language agnostic interface. By bringing Infrastructure as Code best practices to your data, process, and microservice pipelines, you can build reliable workflows directly from the UI in just a few lines of YAML, let the built in AI Copilot write them for you, or generate…
read the full Kestra overview →
About Windmill
Open source developer platform for internal code: APIs, background jobs, workflows and UIs. Self hostable alternative to Retool, Pipedream, Superblocks and a simplified Temporal with autogenerated UIs and custom UIs to trigger workflows and scripts as internal apps. Scripts are turned into sharable UIs automatically, and can be composed together into flows or used into richer apps built with low code. Supported languages: Python, TypeScript, Go, Bash, SQL, GraphQL, PowerShell, Rust, and more. Try it Website Docs Discord Hub Contributing Windmill Developer platform for APIs, background jobs, workflows and UIs…
read the full Windmill overview →
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Frequently asked questions
Is Kestra or Windmill more popular?
Kestra has 30,122 GitHub stars and Windmill has 18,360. Kestra has the larger community by that measure.
Are Kestra and Windmill free?
Both are open source. Kestra is licensed under Apache-2.0, and Windmill has no licence declared in this registry. Both are free to self-host.
What is the difference between Kestra and Windmill?
Kestra is written in Java and Windmill in Rust. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Kestra or Windmill?
Choose Kestra if you want the larger community (30,122 stars) or its Apache-2.0 licence terms. Choose Windmill if its feature set, stack or Custom / other licence fits better. Both are self-hostable.