head to head · open source
Langflow vs Fonoster
Langflow has 154,943 GitHub stars, 10,108 forks, 1,056 open issues and last shipped yesterday. Fonoster has 8,113 stars, 555 forks, 22 open issues and last shipped 2 days ago. Langflow leads on adoption by 1,810% (154,943 vs 8,113 stars). Langflow is written in Python under MIT; Fonoster is written in TypeScript under MIT. Langflow has attracted 7% as many forks as stars, Fonoster 7%. Langflow was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Langflow | Fonoster | |
|---|---|---|
| GitHub stars | ★ 155K | ★ 8.1K |
| License | MIT | MIT |
| Written in | Python | TypeScript |
| Last push | 2026-09-17 | 2026-09-16 |
| Forks | ⑂ 10K | ⑂ 555 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Langflow if
- You weight community size — 155K stars and counting
- You want the MIT license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick Fonoster if
- You want the Fonoster feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and Fonoster fits your workflow better
About Langflow
Langflow is a visual builder platform for designing, testing, and deploying AI agents and retrieval augmented generation (RAG) pipelines. It lives in the Python based generative AI ecosystem and targets developers building intelligent applications. The project provides a low code interface to assemble components—such as LLMs, vector stores, memory modules, and tools—into executable workflows, while also exposing those workflows as APIs or MCP servers for integration into external applications.
read the full Langflow overview →
About Fonoster
Fonoster is an MIT licensed TypeScript platform for programmable voice and telephony that is positioned as the open source alternative to Twilio, and it is aimed at developers and platform teams building cloud communications, voice applications and customer engagement products.
read the full Fonoster overview →
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Frequently asked questions
Is Langflow or Fonoster more popular?
Langflow has 154,943 GitHub stars and Fonoster has 8,113. Langflow has the larger community by that measure.
Are Langflow and Fonoster free?
Both are open source. Langflow is licensed under MIT and Fonoster under MIT. Neither carries a licence fee.
What is the difference between Langflow and Fonoster?
Langflow is written in Python and Fonoster in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Langflow or Fonoster?
Choose Langflow if you want the larger community (154,943 stars) or its MIT licence terms. Choose Fonoster if its feature set, stack or MIT licence fits better. Both are self-hostable.