Langfuse
An open-source LLM engineering platform for observability, analytics, and evaluation. Langfuse provides tracing for LLM applications, prompt management, evaluation pipelines, and cost tracking. It helps teams debug, analyze, and improve their LLM applications in production.
Implements
Concepts this tool claims to implement:
- Benchmark primary
Evaluation pipelines with human annotation, LLM-as-judge, and custom scorers. Track evaluation scores over time. A/B testing for prompts.
- Prompt Template secondary
Prompt management with versioning, deployment, and rollback. Separate prompt changes from code deployments.
- Faithfulness secondary
Built-in and custom evaluators for measuring generation quality. Supports hallucination detection evaluators.
Integration Surfaces
Details
- Vendor
- Langfuse GmbH
- License
- MIT (core) / Commercial (cloud)
- Runs On
- local, cloud, hybrid
- Used By
- human, system
Links
Notes
Langfuse is the leading open-source alternative to LangSmith. Can be self-hosted or used as managed cloud service. Strong focus on developer experience and integrations. The open-source nature makes it popular with teams that want control over their observability data.