Windmill

Windmill brings scripts, workflow automation and interface building together for teams creating internal software. It is best suited to groups that want developers and operational teams to work from the same platform. The trade-off is that self-hosting and security configuration need deliberate attention.

Overview

Teams in engineering, data, sales, support and marketing can use Windmill to build internal tools. Developers can write scripts in TypeScript, Python, Go, PHP, Bash, C#, SQL, Rust, Ruby and R, among other languages; others can assemble workflows and applications with low-code builders. React and Svelte app builders add an option for teams building interfaces with those frameworks.

This mix suits organizations whose internal software needs range from coded services to workflow-driven apps. It also means teams must decide how much to build in code and how much to use the visual builders. Windmill supports self-hosting, local development through its CLI, and Git sync for version control and deployment workflows. Those capabilities give technical teams deployment and development options, but self-hosting makes security setup important: PID namespace isolation is disabled by default, and NSJAIL sandboxing is optional.

Key features

Scripts, workflows and triggers

Scripts and flows can run on webhooks, schedules, HTTP routes, queues or through the open API. This range supports both scheduled jobs and work that responds to events or requests. Reusable workflows can help teams structure recurring automation, though the value depends on having people able to maintain the underlying scripts and flows.

Builders and integrations

A script editor sits alongside a low-code flow builder and low-code, React and Svelte app builders. That breadth can serve developers and colleagues who need to assemble internal interfaces without using the same development approach. Windmill's Hub includes more than 200 resource types, with integrations such as GitHub, Slack, AWS, BigQuery and PostgreSQL. Teams can also define custom resource types through schemas with fields and constraints, which is useful when a required connection is not covered by an existing resource.

Access and support

Enterprise features include granular permissions, RBAC, secret management, OAuth, SSO and audit logs. These controls address access and oversight needs for larger or more sensitive deployments, while the documented isolation defaults still warrant review before self-hosting. The free self-hosted plan has community support on Discord; Enterprise adds 24/7 priority support with a three-hour response time.

Pricing

Windmill is freemium, with a 30-day Enterprise trial and paid pricing from $120/mo. The free plan, Free and Open-source, costs nothing, billed monthly. It allows 3 workspaces, 50 users, 10 GiB of workspace object storage and 100 guest app users per 30 days. Those caps make it a substantial starting point for teams evaluating or running internal tools, but organizations with more workspaces, storage or guest use will need to account for the limits.

Enterprise costs $120 a month, billed from $120/mo. It adds Enterprise features, uncapped SSO that requires seats, 24/7 priority support with a three-hour response time, and a commercial licence. The plan is aimed at organizations that need those capabilities and support; the free plan gives up the commercial licence and priority support. The 30-day trial is for Enterprise.

Platforms

Windmill supports API, Linux, self-hosted, web and Windows. Self-hosting is a meaningful option for teams with deployment requirements, while web access and API support accommodate other ways of working with the platform.

Who it's for

Windmill is a strong fit for teams building internal software across technical and operational functions, especially when they want code, low-code workflows and app interfaces in the same platform. Its language range, custom resource types and local development options favor teams with engineering capacity. It is less compelling for organizations that want a managed, tightly isolated deployment without taking responsibility for security settings.

Pros and cons

• Broad ways to build: scripting, low-code flows, and low-code, React or Svelte apps let teams choose an approach for different internal tools.
• Flexible connections: more than 200 Hub resource types, custom schemas and several trigger types cover varied integration and automation needs.
• Usable free allowance: 50 users and 3 workspaces provide room to start, subject to storage and guest-user caps.
• Security setup needs care: PID namespace isolation is off by default and NSJAIL sandboxing is optional, so self-hosting requires attention to isolation requirements.
• Enterprise costs more: the $120.00 monthly entry price is necessary for the commercial licence and priority support.

Alternatives

Choose Knit instead if API integration is the priority and a 100K API calls/month plan at $499 a month fits the budget; its Start Up plan also includes unlimited data usage, 3 test accounts and 3-day log retention. Apache Camel is a free option under the Apache License 2.0 for teams seeking a no-cost, self-hosted tool. Apache NiFi is another free, Apache-licensed option, with API, web and self-hosted platforms among its stated support.

Celigo may suit teams whose needs fit its free allowance of 2 endpoints, 1 flow and 1 production environment. Nango is worth considering for teams focused on connections, with 10 connections, 10 hours of compute per month and 10GB of data transfer on its free plan. Workato Agent Studio offers a free plan with 50,000 one-time credits and AI and agentic capabilities. Google Cloud Application Integration may fit teams looking for a free tier with up to 400 integration executions and up to 20 GiB of data processed per month. Superfeedr is another freemium alternative.

Readers comparing broader categories can explore API Integration Platforms, Internal Tools Software, IT Orchestration Software, Task Automation Software, Workload Automation Software and Workflow Orchestration Software.

Verdict

Choose Windmill if your team is building internal software and wants scripts, workflow automation and app creation under one roof, with the option to self-host. The free plan offers room to start, and Enterprise adds a commercial licence and priority support. Look elsewhere if your deployment needs stronger isolation by default or you do not want to take on security configuration.