Evaluation and observabilityOpen sourceUpdated 2026
Langfuse
Intermediate · Observability platform
Open-source observability, tracing, prompt management, and evaluation platform for LLM apps.
Best for
Teams shipping LLM apps that need traces, evaluations, prompts, and production visibility.
Why use it
Good fit when prototypes need to become monitored products.
Tradeoffs
Requires instrumentation discipline and clear evaluation criteria.
Key features
- Tracing
- Prompt management
- Evaluations
Alternatives
Phoenix, LangSmith, OpenTelemetry
Where it fits
Langfuse belongs in the evaluation and observability layer of an open AI stack. Evaluate it against your model runtime, privacy needs, deployment target, and the amount of operational complexity your team can support.
CategoryEvaluation and observabilityLicenseMITDeploymentObservability platformModeSelf-hosted or cloud
Langfuse GitHub →Recommendation
Use Langfuse when LLM app behavior needs to be observed and evaluated.