Langfuse
See what your LLM app actually did
LLM / RAG frameworkLLM observabilityMITRuns locallyTypeScriptIntermediate
🐳 Docker pulls
📦 PyPI downloads / month
📦 npm downloads / month
🚀 Latest release ·
What is Langfuse?
Langfuse traces every LLM call, tool use and cost in your application, with prompt management and evaluation built in — self-hostable.
Why people choose Langfuse
- Full tracing of chains and agents
- Cost and latency tracking
- Self-hosted, MIT licensed
Langfuse at a glance
| Category | LLM / RAG framework |
| Type | LLM observability |
| License | MIT |
| Runs locally | Yes |
| Built with | TypeScript |
| Skill level | Intermediate |
| Best for | debugging and monitoring LLM apps in production |
Latest releases
Open-source alternatives to Langfuse
Other open-source llm / rag framework tools worth comparing:
LangChainCompose chains, tools and agents
LlamaIndexThe data framework for RAG
HaystackProduction pipelines for search and RAG
DSPyProgram — not prompt — language models
txtaiAll-in-one embeddings database
RAGFlowDeep-document-understanding RAG
Semantic KernelMicrosoft's enterprise agent frameworkGraphRAGRAG that builds a knowledge graph first
LiteLLMOne API for 100+ LLM providers
InstructorReliable structured outputs from LLMs
OutlinesGuarantee valid JSON and grammars
GuidanceInterleave control and generation
LLMWareEnterprise RAG with small specialised models
FlashRankUltra-light reranking for better RAG
Sentence TransformersThe standard way to make embeddings
RagasMeasure whether your RAG is any good
PromptfooUnit tests for your prompts
PhoenixTrace, evaluate and debug LLM appsLangfuse head-to-head
Langfuse vs LangChainLangfuse vs LlamaIndexLangfuse vs HaystackLangfuse vs DSPyLangfuse vs txtaiLangfuse vs RAGFlowLangfuse vs Semantic KernelLangfuse vs GraphRAGLangfuse vs LiteLLMLangfuse vs InstructorLangfuse vs OutlinesLangfuse vs GuidanceLangfuse vs LLMWareLangfuse vs FlashRankLangfuse vs Sentence TransformersLangfuse vs RagasLangfuse vs PromptfooLangfuse vs Phoenix
FAQ
Is Langfuse free?
Langfuse is free and open-source (MIT license), so you can use, self-host and modify it at no cost.
Can I run Langfuse locally?
Yes. Langfuse is designed to run on your own machine or server, keeping your data private.
What is the best alternative to Langfuse?
Popular open-source alternatives include LangChain, LlamaIndex, Haystack. See the comparisons above to choose.
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