head to head · open source
Kestra vs Windmill
Kestra has 28,148 GitHub stars, 2,999 forks, 713 open issues and last shipped yesterday. Windmill has 17,958 stars, 1,096 forks, 852 open issues and last shipped today. Kestra leads on adoption by 57% (28,148 vs 17,958 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 11% as many forks as stars, Windmill 6%. Windmill was the more recently maintained of the two, and both are self-hostable with no licence fee.
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 | ★ 28K | ★ 18K |
| License | Apache-2.0 | Custom / other |
| Written in | Java | Rust |
| Last push | 2026-09-17 | 2026-09-18 |
| Forks | ⑂ 3.0K | ⑂ 1.1K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Kestra if
- You weight community size — 28K 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
Kestra is an open source, event driven orchestration platform for data, AI, and infrastructure workflows. It operates in the Java based ecosystem and is licensed under Apache 2.0. The project provides a unified interface for both scheduled and real time automation, supporting declarative workflow definitions in YAML while also offering visual and AI assisted authoring.
read the full Kestra overview →
About Windmill
Windmill is an open source developer platform for internal code, including APIs, background jobs, workflows, and UIs. It lives in the self hostable low code automation ecosystem and supports Python, TypeScript, Go, Bash, SQL, GraphQL, PowerShell, Rust, and more. The project is positioned as an open source alternative to Zapier and, in the README, to Retool, Pipedream, Superblocks, and a simplified Temporal.
read the full Windmill overview →
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Frequently asked questions
Is Kestra or Windmill more popular?
Kestra has 28,148 GitHub stars and Windmill has 17,958. 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 (28,148 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.