head to head · open source
Dify vs Letta
Dify has 156,167 GitHub stars, 24,658 forks, 1,067 open issues and last shipped yesterday. Letta has 3,366 stars, 411 forks, 347 open issues and last shipped yesterday. Dify leads on adoption by 4,540% (156,167 vs 3,366 stars). Dify is written in TypeScript under a custom or non-standard licence; Letta is written in TypeScript under Apache-2.0. Dify has attracted 16% as many forks as stars, Letta 12%. Letta was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (ai, claude), so they are genuine substitutes rather than adjacent tools.
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
| Dify | Letta | |
|---|---|---|
| GitHub stars | ★ 156K | ★ 3.4K |
| License | Custom / other | Apache-2.0 |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 25K | ⑂ 411 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Dify if
- You weight community size — 156K stars and counting
- You want the Custom / other license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick Letta if
- You want the Letta feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and Letta fits your workflow better
About Dify
Dify is an open source LLM application development platform built in TypeScript. It provides a visual interface for designing, testing, and deploying AI workflows, RAG pipelines, and agentic systems without writing extensive code. The platform lives in the generative AI development ecosystem and targets teams needing to move from prototype to production using consistent tooling across environments.
About Letta
Letta Code is an open source TypeScript harness under Apache 2.0 for stateful AI agents. It lives in the AI & Machine Learning / AI Development Platforms ecosystem. It gives agents memory, identity, and a sense of experience over time. It targets agents that behave more like people than tools.
read the full Letta overview →
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Frequently asked questions
Is Dify or Letta more popular?
Dify has 156,167 GitHub stars and Letta has 3,366. Dify has the larger community by that measure.
Are Dify and Letta free?
Both are open source. Dify has no licence declared in this registry, and Letta is licensed under Apache-2.0. Both are free to self-host.
What is the difference between Dify and Letta?
Dify is written in TypeScript and Letta 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, Dify or Letta?
Choose Dify if you want the larger community (156,167 stars) or its Custom / other licence terms. Choose Letta if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.