LangSmith
LangChain's eval + observability platform.
LangSmith is the LangChain team's eval and observability product — tracing, evals, datasets, and prompt playground. Pairs naturally with LangChain/LangGraph but works standalone too.
Pros
- ✅ Tight LangChain integration
- ✅ Strong tracing UX
- ✅ Mature dataset/eval flows
Cons
- ⚠️ Best value if you're on LangChain
- ⚠️ UI can feel dense
Use cases
LLM tracingevalsLangChain integration
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Braintrust
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8.9
Eval, monitor, and improve AI products end-to-end.
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The ML experiment tracker, now with LLM eval features.
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Helicone
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Open-source LLM observability — one-line proxy install.
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Humanloop
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8.2
Prompt management + evals for collaborative AI teams.
Paid· From $200/mo teamprompt managementteam collab
PromptLayer
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Lightweight prompt logging + management for OpenAI/Claude apps.
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Patronus
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Automated LLM evaluation for hallucinations, safety, and quality.
Paid· Enterprise pricinghallucination detectionsafety