Workflow automation
What it costs to self-host Windmill
Open-source developer platform to power your entire infra and turn scripts into webhooks, workflows and UIs. Fastest workflow engine (13x vs Airflow). Open-source alternative to Retool and Temporal. Below is the server it needs at each team size, what that costs, and how long the 2 commercial products it replaces would take to cost more.
| Team size | Memory | Disk | Cheapest plan that fits | Server | With backups and your time |
|---|---|---|---|---|---|
| solo | 2.5 GB | 15.1 GB | CX23 (cost-optimized) · Hetzner Cloud | $6.70 | $121 |
| 5 people | 2.6 GB | 15.5 GB | CX23 (cost-optimized) · Hetzner Cloud | $6.70 | $121 |
| 10 people | 2.6 GB | 16 GB | CX23 (cost-optimized) · Hetzner Cloud | $6.70 | $121 |
| 25 people | 2.8 GB | 17.5 GB | CX23 (cost-optimized) · Hetzner Cloud | $6.70 | $121 |
| 50 people | 3.1 GB | 20 GB | CX23 (cost-optimized) · Hetzner Cloud | $6.70 | $121 |
| 100 people | 3.7 GB | 25 GB | CX23 (cost-optimized) · Hetzner Cloud | $6.70 | $121 |
| 250 people | 5.5 GB | 40 GB | CX33 (cost-optimized) · Hetzner Cloud | $10.06 | $125 |
The sizing model for Windmill
Rust server with PostgreSQL and one or more workers. Faster per job than the Node-based options, which matters if the workflow count is high.
- 2 GB of memory for the whole stack at rest, every container the project ships included.
- 10 MB more per active user, then 25% on top so the box is not running at its ceiling.
- 15 GB of disk to begin with, growing 0.1 GB per user.
- 2 vCPU. Carried through from the project's baseline and not scaled with team size, because for this workload memory is what runs out first.
These base figures come from the project's own documented requirements. The per-user increments are ours in every case. They are deliberately generous rather than optimistic: a comparison that undersizes the server flatters self-hosting.
Time, not just money
Windmill is rated medium to operate, which in this model means about 6 hours to get it running properly the first time and 1.5 hours a month after that. At $75 an hour that is $450 once and $112 a month, which is usually the largest line in the whole calculation.
What it replaces
| Commercial product | Its cost at 10 people | Windmill at 10 people | Break-even | |
|---|---|---|---|---|
| Retool Team | $55.96 | $121 | never | full breakdown |
| Zapier Professional | $29.99 | $121 | never | full breakdown |
Where to put Windmill
2.6 GB of memory and 16 GB of disk is what this needs at 10 people. The cheapest plan that fits, among the providers whose prices we have read ourselves, is the CX23 (cost-optimized) at Hetzner Cloud for $6.70 a month.
Go to Hetzner Cloud Compare hosts
We are not claiming this is the cheapest server on the internet. It is the cheapest one we can honestly quote. Vultr and PikaPods publish prices we could not read programmatically, and may well undercut it. Price them yourself before you commit.
Project facts
| Licence | Other not a standard open-source licence |
|---|---|
| Written in | Rust |
| GitHub stars | 17,901 |
| Open issues | 845 |
| Latest release | v1.811.0 |
| Last commit | 2026-09-12 |
| Repository checked | 2026-09-12 |
| Project | www.windmill.dev · windmill-labs/windmill |
Get the migration checklist for this tool
A one-page pre-flight list: data export path, sizing, backup plan, and the rollback step most people skip.