Langflow vs Sim
A side-by-side comparison of capabilities, autonomy, integrations, and pricing to help you choose.
Short answer: choose Langflow if you want open-source visual low-code builder for ai agents and rag apps (Supervised agent, freemium); choose Sim if you want open-source visual platform to build, deploy, and manage ai agent workflows (Supervised agent, freemium).
| Langflow | Sim | |
|---|---|---|
| What it is | Open-source visual low-code builder for AI agents and RAG apps | Open-source visual platform to build, deploy, and manage AI agent workflows |
| Type | platform | platform |
| Autonomy | Supervised agent | Supervised agent |
| Pricing | freemium · Self-host free (open source); managed/cloud options available | freemium · Free (Community); Pro $25/mo |
| Best for | developers, smb, enterprise | developers, smb, mid-market, enterprise |
| Deployment | self-hosted, saas | saas, self-hosted, api |
| Modalities | text, api | text, api, code |
| Models | model-agnostic, open-source | model-agnostic, open-source |
| Protocols | mcp, function-calling, rest-api | mcp, rest-api, function-calling |
| Integrations | OpenAI, Anthropic, Google Gemini, vector databases, DataStax Astra | Slack, Gmail, GitHub, Notion, Airtable, HubSpot |
| Capabilities | 3 documented | 4 documented |
Langflow
- +Open source with a large community and 100k+ GitHub stars
- +Built-in API and MCP servers make every flow a reusable tool
- +Backed by IBM (via DataStax) for continuity and enterprise reach
- -A building platform: you design the flows and their guardrails
- -Visual builders can get unwieldy for very complex logic
Sim
- +Genuinely open-source (Apache 2.0) with first-class self-hosting via Docker, npm, and local models (Ollama, vLLM)
- +Broad model and integration coverage plus multiple deployment modes (API, chat, schedule, webhook, MCP server)
- +Strong momentum: YC-backed with a Series A and tens of thousands of GitHub stars
- -Young company (founded 2025) with a small team and limited enterprise support track record
- -Paid cloud tiers are credit-metered, making costs harder to predict for heavy workloads
Which should you choose?
Langflow is open-source visual low-code builder for ai agents and rag apps, best for developers, smb, enterprise. Sim is open-source visual platform to build, deploy, and manage ai agent workflows, best for developers, smb, mid-market, enterprise. The right choice depends on the autonomy level you want, your existing integrations, and your budget, all compared above.