Windmill vs 
Kestra
Windmill vs Kestra compared for 2026 — features, license, ease of use, performance and which one to choose. Turn scripts into workflows and UIs vs Declarative orchestration with AI steps.
Updated regularly · curated by OpenSourceAI.tech
Windmill vs Kestra at a glance
| Spec | Windmill | Kestra |
|---|---|---|
| Category | Low-code AI builder | Low-code AI builder |
| Type | Workflow platform | Orchestration platform |
| License | AGPL-3.0 | Apache-2.0 |
| Runs locally | Yes | Yes |
| Primary language | Rust | Java |
| Ease of use | Intermediate | Intermediate |
| Best for | developer-first internal tooling | data pipelines that include AI steps |
| GitHub stars | — | 27.4k |
How Windmill and Kestra score
| Criterion | Windmill | Kestra |
|---|---|---|
| Popularity | n/a | 3.5 |
| Maintenance | n/a | 5.0 |
| Ease of use | 3.5 | 3.5 |
| Privacy | 5.0 | 5.0 |
| License freedom | 3.5 | 5.0 |
Scores are computed automatically from public signals — GitHub stars (popularity), recent commit activity (maintenance), license type (freedom), local-first design (privacy) and onboarding complexity (ease of use). Indicative, not a verdict.
What each one is
Windmill
Windmill turns Python, TypeScript or SQL scripts into workflows, schedules and internal apps, with AI steps as first-class citizens.
- Scripts first, UI generated for you
- Very fast execution engine
- Self-hosted, no vendor lock-in
Kestra
Kestra orchestrates data and AI workflows declaratively in YAML, with a UI, scheduling and hundreds of plugins.
- Declarative YAML workflows
- Handles large data pipelines
- Rich plugin ecosystem
Key differences
Windmill is workflow platform, while Kestra is orchestration platform. Their licenses differ (AGPL-3.0 vs Apache-2.0), which matters if you ship a commercial product. In short, Windmill fits developer-first internal tooling, and Kestra fits data pipelines that include AI steps.
Which should you choose?
Choose Windmill for developer-first internal tooling. Choose Kestra for data pipelines that include AI steps.
There is rarely one winner — many setups use both. The right pick depends on your hardware, your team's skills, and whether you value simplicity or control.
Frequently asked questions
Is Windmill or Kestra easier to use?
Both sit at a similar level (Intermediate). Your choice should come down to fit rather than difficulty.
Are Windmill and Kestra free?
Windmill is free and open source (AGPL-3.0), and Kestra is free and open source (Apache-2.0). Neither charges for the core software.
Can I run Windmill and Kestra locally?
Windmill: yes · Kestra: yes. Both can be used without sending your data to a third-party cloud where their setup allows.
Windmill vs Kestra — which should I pick in 2026?
Choose Windmill for developer-first internal tooling. Choose Kestra for data pipelines that include AI steps.
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