head to head · open source
Langfuse vs LangWatch
Langfuse has 34,826 GitHub stars, 3,815 forks, 926 open issues and last shipped 2 days ago. LangWatch has 4,833 stars, 395 forks, 939 open issues and last shipped 2 days ago. Langfuse leads on adoption by 621% (34,826 vs 4,833 stars). Langfuse is written in TypeScript under a custom or non-standard licence; LangWatch is written in TypeScript under Apache-2.0. Langfuse has attracted 11% as many forks as stars, LangWatch 8%. LangWatch was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 5 topic tags (analytics, evaluation, llm, llmops), 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
| Langfuse | LangWatch | |
|---|---|---|
| GitHub stars | ★ 35K | ★ 4.8K |
| License | Custom / other | Apache-2.0 |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-19 | 2026-09-19 |
| Forks | ⑂ 3.8K | ⑂ 395 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Langfuse if
- You weight community size — 35K 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 LangWatch if
- You want the LangWatch 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 LangWatch fits your workflow better
About Langfuse
Langfuse is an open source LLM engineering platform for building, monitoring, and improving AI powered applications. It lives in the LLMops ecosystem and provides tooling for the full development lifecycle—from prompt iteration and evaluation to observability and dataset management. Built with TypeScript and powered by ClickHouse, it enables teams to track LLM calls, user sessions, and internal logic like retrieval or agent actions in a unified interface.
read the full Langfuse overview →
About LangWatch
LangWatch is an open source TypeScript platform for LLM evaluations and AI agent testing, licensed under Apache 2.0. It lives in the machine learning infrastructure ecosystem for teams that build LLM powered agents and need to test, simulate, evaluate, and monitor agents before release and in production.
read the full LangWatch overview →
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Frequently asked questions
Is Langfuse or LangWatch more popular?
Langfuse has 34,826 GitHub stars and LangWatch has 4,833. Langfuse has the larger community by that measure.
Are Langfuse and LangWatch free?
Both are open source. Langfuse has no licence declared in this registry, and LangWatch is licensed under Apache-2.0. Both are free to self-host.
What is the difference between Langfuse and LangWatch?
Langfuse is written in TypeScript and LangWatch 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, Langfuse or LangWatch?
Choose Langfuse if you want the larger community (34,826 stars) or its Custom / other licence terms. Choose LangWatch if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.