Langflow
Visual builder for AI agents and RAG pipelines — LangChain-powered.
MIT-licensed alternative to Flowise with Python code nodes, multi-agent orchestration, and vector store integration. pip install or Docker.
Langfuse
LLM engineering platform — tracing, prompt management, cost tracking.
MIT-licensed alternative to LangSmith. Full observability for LLM chains, version-controlled prompts, A/B testing, and dataset evaluation.
Helicone
LLM observability and AI gateway — one-line integration for logging, cost tracking, prompt management, and rate limiting
Build reliable AI apps with comprehensive observability
Laminar
Agent observability and evaluation platform — signal alerts, trace debugging, and automated evals for LLM products
Open-source LLM observability platform — trace debugging, signal alerts, and automated evaluations for AI products. Alternative to LangSmith and Helicone.
Compare LangSmith alternatives
LangSmith is LangChain's proprietary platform for tracing, evaluating, and monitoring LLM applications. It integrates tightly with the LangChain ecosystem, but tracing data is sent to a hosted service and pricing scales with trace volume.
Open-source alternatives give you the same observability without sending data to a third party, and work with any framework, not just LangChain. If you're specifically using LangChain to build agents, note that Langflow is a visual agent builder, not an observability tool — pair it with Langfuse or Helicone if you need both.
FAQ
Is there a free, open-source alternative to LangSmith?
Yes. Langfuse, Helicone, and Laminar are all open source and self-hostable at no software cost.
What's the best open-source alternative to LangSmith?
Langfuse is the closest direct match for tracing, prompt management, and cost tracking. Helicone is a good fit if you want observability added with minimal code changes via a gateway.
Do these alternatives work outside of LangChain?
Yes. Langfuse, Helicone, and Laminar are all framework-agnostic and work with any LLM provider or agent framework, not just LangChain.
What are the top open-source alternatives to LangSmith?
Browse all open-source alternatives to LangSmith above, or explore the full Analytics & Data category for more options.