What is the best free alternative to Stack AI?
Windmill is the closest free alternative to Stack AI: same Workflow Automation sub-category, and it is free. Open-source, self-hostable with unlimited executions on the free tier
Best free Stack AI alternatives
Looking for a free alternative to Stack AI? Here are 9 workflow automation worth trying — 9 with a free tier. Stack AI itself is free tier + paid.
| Tool | Stack AI (you searched) | Windmill | Langflow | Zapier |
|---|---|---|---|---|
| Pricing | freemium | free | free | freemium |
| Best for | Free plan: 500 monthly runs, 2 projects, 1 seat, community Discord support | Open-source, self-hostable with unlimited executions on the free tier | Open source with 138k GitHub stars, free desktop app and free cloud account | Connect 8,000+ apps with AI agents |
| Visit | Open ↗ | Open ↗ | Open ↗ | Open ↗ |
Stack AI alternatives — straight answers
Are there free Stack AI alternatives?
Yes — 9 of the 9 alternatives listed here are free or freemium: Windmill, Langflow, Zapier, n8n, Make. None of them are paid-only.
Is Stack AI free?
Stack AI is free tier + paid. There is a free tier you can work in, with paid plans above it.
How were these Stack AI alternatives chosen?
They are the other tools in Workflow Automation, then the rest of AI Agents & Automation, ordered free tiers first and capped at 9. There is no sponsorship and no paid placement in that ordering — only the pricing tier decides.
All Stack AI alternatives
Browse Workflow Automation →Windmill
Workflow Automation
✦ WhyA Stack AI alternative — Open-source, self-hostable with unlimited executions on the free tier.
- Open-source, self-hostable with unlimited executions on the free tier
- Turns scripts (Python/TS/Go/Bash/SQL) into flows and full internal apps
- Kubernetes/Docker/Fargate deployable with a hybrid seat+compute enterprise pricing model
Langflow
Workflow Automation
✦ WhyA Stack AI alternative — Open source with 138k GitHub stars, free desktop app and free cloud account.
- Open source with 138k GitHub stars, free desktop app and free cloud account
- Drag-and-drop visual builder for agents and RAG pipelines on top of LangChain primitives
- Deep integrations across major LLMs, vector DBs and Google Cloud/Slack/MongoDB
Zapier
Workflow Automation
✦ WhyA Stack AI alternative — Connect 8,000+ apps with AI agents.
- Connect 8,000+ apps with AI agents
- Natural-language automation builder
- AI steps, chatbots and tables
- Free tier for basic Zaps
n8n
Workflow Automation
✦ WhyA Stack AI alternative — Open-source, self-hostable automation.
- Open-source, self-hostable automation
- Visual AI-agent and LLM nodes
- Full code when you need it
- Free to run yourself
Make
Workflow Automation
✦ WhyA Stack AI alternative — Visual drag-and-drop automation.
- Visual drag-and-drop automation
- AI modules and agent scenarios
- 1,000+ app integrations
- Generous free tier
Lindy
Workflow Automation
✦ WhyA Stack AI alternative — Build AI 'employees' from plain English.
- Build AI 'employees' from plain English
- Handles email, scheduling and CRM tasks
- Trigger-based autonomous workflows
- Free starter plan
Gumloop
Workflow Automation
✦ WhyA Stack AI alternative — No-code canvas for AI workflows.
- No-code canvas for AI workflows
- Web scraping, extraction and enrichment
- Shareable automation templates
- Free plan to start
Coze
Workflow Automation
✦ WhyA Stack AI alternative — No-code drag-and-drop bot/agent builder from ByteDance, distinct from Doubao's consumer chat app.
- No-code drag-and-drop bot/agent builder from ByteDance, distinct from Doubao's consumer chat app
- 60+ built-in plugins (search, travel, productivity) wired into published bots
- One-click publish to Telegram, Discord, Slack or your own site
Activepieces
Workflow Automation
✦ WhyA Stack AI alternative — MIT-licensed, free-forever self-hosted Community Edition with unlimited runs/users/flows.
- MIT-licensed, free-forever self-hosted Community Edition with unlimited runs/users/flows
- 700+ integrations plus AI-agent building blocks
- Cloud Free plan needs no credit card, includes unlimited flows with daily credit resets