Relay.app
Windmill
| Feature | Relay.app | Windmill |
|---|---|---|
| Pricing | Free / from $16/mo | Free / from $10/mo |
| Free Plan | ✓ Yes | ✓ Yes |
| Rating | 4.3 / 5 | 4.4 / 5 |
| Best For | operations-teams, agencies, small-businesses, compliance-teams | developers, devops-teams, internal-tools, data-pipelines |
| Founded | 2021 | 2022 |
| Workflow Builder | ✓ | ✗ |
| Ai Steps | ✓ | ✗ |
| Human Approvals | ✓ | ✗ |
| Multiplayer Editing | ✓ | ✗ |
| Integrations | ✓ | ✗ |
| Conditional Logic | ✓ | ✗ |
| Workflow Editor | ✗ | ✓ |
| Script To Ui | ✗ | ✓ |
| Scheduling | ✗ | ✓ |
| Approval Flows | ✗ | ✓ |
| Multi Language | ✗ | ✓ |
| Self Hostable | ✗ | ✓ |
| Audit Logs | ✗ | ✓ |
✓ Relay.app Pros
- Human-in-the-loop approvals
- AI steps built in
- Collaborative workflows
- Clean modern interface
✗ Relay.app Cons
- Fewer integrations than Zapier
- Newer platform
- Limited advanced logic
✓ Windmill Pros
- Open-source and self-hostable
- Supports Python, TypeScript, Go, Bash, SQL natively
- Auto-generates UI from script parameters
- Excellent scheduling and workflow orchestration
✗ Windmill Cons
- Smaller community than Zapier/n8n
- Self-hosting requires infrastructure knowledge
- Less polished documentation for beginners
The Verdict
Relay.app is built for operations teams and agencies, with a focus on workflow-builder and ai-steps. Windmill targets developers and devops teams and leads with workflow-editor and script-to-ui.
On pricing, Windmill is the clear winner for budget-conscious users — starting at $10/mo compared to $16/mo for Relay.app. That $6/mo difference adds up quickly for growing teams.
Both offer free plans, so you can test each with your real workflow before committing to a subscription.
Feature-wise, Windmill offers broader built-in capabilities (7 features vs 6), while Relay.app takes a more focused approach — which can mean a simpler, faster onboarding experience.
This is a genuinely close comparison. If you can, sign up for both free trials (where available) and run a one-week test with your actual team tasks before deciding.