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Kestra vs Windmill

A side-by-side comparison of two self-hosted automation & workflows options — licensing, setup difficulty, resource needs, and what each one replaces.

Not the right match-up?
Kestra Declarative orchestration and scheduling platform VS Windmill Developer platform for scripts, flows and apps
FeatureKestraWindmill
Deploy effortUnder-an-hour setupUnder-an-hour setup
Health score97 · Excellent95 · Excellent
CategoryAutomation & WorkflowsAutomation & Workflows
LicenseApache-2.0AGPL-3.0
LanguageJavaRust
Setup difficultyHardMedium
Min. RAM1,024 MB1,024 MB
Deploymentdocker, kubernetesdocker, kubernetes
GitHub stars★ 28,316★ 18,022
First released20212022
ReplacesZapier, MakeZapier, Retool

What are Kestra and Windmill?

Kestra

Kestra is an event-driven orchestration platform for building and scheduling data and automation workflows declared in YAML. It targets data engineers and platform teams. It is deployed via Docker.

  • Declarative YAML workflows
  • Event-driven and scheduled runs
  • Rich plugin ecosystem
  • Built-in UI and API

Read the full Kestra guide →

Windmill

Windmill is a developer platform that turns scripts into workflows, APIs, and internal apps with scheduling and approvals. It targets engineers automating internal tooling. It is deployed via Docker with PostgreSQL.

  • Scripts in Python, TypeScript and more
  • Auto-generated UIs for scripts
  • Flows with branching and retries
  • Fast Rust execution engine

Read the full Windmill guide →

Kestra vs Windmill: key differences

Kestra is written in Java, while Windmill is built with Rust. Licensing differs — Apache-2.0 for Kestra versus AGPL-3.0 for Windmill.

Why pick each one

Choose Kestra if…

  • Strong for data orchestration
  • Scalable architecture
  • Open-source license

Watch out for

  • Steeper learning curve
  • Heavier resource needs
Kestra details

Choose Windmill if…

  • Great for developer automation
  • Fast and scalable
  • Code-first approach

Watch out for

  • More technical than no-code tools
  • Requires Postgres
Windmill details

Frequently asked questions

Is Kestra or Windmill better?

Neither is universally better. Kestra has the larger community, while Windmill is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.

Are Kestra and Windmill free and open-source?

Yes. Kestra is licensed under Apache-2.0 and Windmill under AGPL-3.0. Both can be self-hosted at no software cost.

Can I run Kestra and Windmill with Docker?

Kestra: yes. Windmill: yes.

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