Windmill
Open-source developer platform to turn scripts into workflows and UIs.
What it replaces
What Windmill actually is
Windmill is an open-source developer platform for turning scripts into webhooks, workflows, and UIs. In practical terms, it sits somewhere between automation tools like Zapier, internal-tool builders like Retool, and developer platforms such as Airplane. The intended user is not someone trying to connect a spreadsheet to an email account in five minutes; it is a developer or technical team that wants to keep the logic in code while still exposing it through operational workflows and interfaces. That makes Windmill a more serious option than a pile of drag-and-drop SaaS automations, provided your team is comfortable owning the machinery.
Live GitHub stats
Windmill has 17,659 GitHub stars and 1,080 forks, which is enough public adoption to make it more than an abandoned weekend project. GitHub lists the license as NOASSERTION, so treat the licensing situation as something to verify against the repository and Windmill's current commercial terms before building a business-critical product around it. The primary language is Rust, a useful signal that performance and systems-level implementation are part of the project's identity rather than just marketing copy. The repository has 824 open issues, which suggests a busy project with plenty of reported work, though an issue count alone does not tell you how responsive maintainers are. The last recorded push was 2026-08-24, indicating active repository maintenance according to the supplied GitHub data.
What it's good at
Windmill's strongest pitch is that it lets developers start with scripts instead of forcing every automation into a visual editor. Those scripts can become webhooks, workflows, and UIs, giving a team one place to move from a small piece of backend logic to something other people can trigger or operate. That is a sensible shape for internal infrastructure: the code remains inspectable, while the surrounding workflow does not need to be rebuilt from scratch every time someone asks for a button.
The relationship to Zapier, Retool, and Airplane is the useful part of the comparison. Windmill can cover automation work that would otherwise accumulate in Zapier, internal tools that might land in Retool, and developer-oriented workflow infrastructure associated with Airplane. It is especially relevant when the workflow is too technical for a no-code automation product but too operationally repetitive to justify a bespoke app. The repository describes Windmill as a “developer platform to power your entire infra,” and its “fastest workflow engine (13x vs Airflow)” claim points toward teams that care about execution speed and workflow infrastructure, not just simple integrations.
That said, Windmill is not automatically a cheaper Zapier with a Rust logo. Self-hosting means the team needs to understand deployment, upgrades, permissions, secrets, and the operational consequences of putting production workflows in the platform. The payoff is control and a code-first workflow model; the cost is that someone has to own it. If your actual requirement is “when this form is submitted, send a notification,” a full developer platform may be an impressive way to create a maintenance obligation.
What to watch for
The biggest immediate caveat is the license field: GitHub reports NOASSERTION, not a clean permissive license such as MIT or Apache-2.0. That is not proof that Windmill is unusable, but it is a reason to read the repository's license files and current self-hosting and commercial-use terms carefully, especially if you plan to modify, resell, or embed it. Deployment difficulty is 3 out of 5: manageable for a technical team, but not something to hand to a non-technical operations group and call solved. The project appears actively maintained based on the last push date of 2026-08-24, while 824 open issues means you should still inspect issue age, release cadence, and maintainer responses before treating the project as boring infrastructure. Boring infrastructure is the goal; the GitHub page does not guarantee it.
How to deploy
Windmill supports both self-hosting and an official cloud offering. For self-hosting, Docker or Docker Compose is the likely path for teams already comfortable operating containerized services, though you should follow the project's current deployment guidance rather than copying an outdated snippet from a blog post. The official cloud option avoids much of that operational work and starts at $10 per month according to the supplied pricing data. See Windmill's current official docs for the current setup path, hosting tradeoffs, and the details that tend to get omitted from glossy “deploy in minutes” claims.
Related tools
Windmill is evaluated here against the same broad jobs as: