Langfuse

Open-source LLM engineering platform

Langfuse provides LLM observability, prompt management, evaluations, and datasets. Open source with a managed cloud option. The leading open alternative to LangSmith.

Panel Reviews

The Builder

Developer Perspective

Ship

“Best open-source LLM observability. Traces, prompt versioning, and evals in one tool. Self-hosting option is a must.”

The Skeptic

Reality Check

Ship

“Open source means no vendor lock-in. The tracing UI is clean and the integration with LangChain and Vercel AI SDK is seamless.”

The Futurist

Big Picture

Ship

“LLM observability is becoming as essential as APM. Langfuse is the Grafana of AI — open source and community-driven.”