Weights & Biases
The ML experiment tracker, now with LLM eval features.
W&B is the dominant ML experiment tracking tool, with strong LLM eval and prompt management features (W&B Weave). Excellent for teams already on W&B for traditional ML.
Pros
- ✅ Industry-standard for ML tracking
- ✅ Weave adds LLM-native eval
- ✅ Mature, reliable
Cons
- ⚠️ Heavier UX than LLM-native tools
- ⚠️ LLM features still catching up
Use cases
ML experimentsLLM evalWeave
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Braintrust
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8.9
Eval, monitor, and improve AI products end-to-end.
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LangSmith
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LangChain's eval + observability platform.
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Helicone
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8.3
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.
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