📖 The AI Tool Bible

Opik vs Weights & Biases

A side-by-side look at pricing, capabilities, pros, cons, and our editorial scores.

 
Opik
Evaluation
Weights & Biases
Evaluation
TaglineOpen-source LLM observability and evaluation platform for debugging and monitoring AI agents in production.The ML experiment tracker, now with LLM eval features.
CategoryEvaluationEvaluation
PricingFreemium· Free open-source self-host; free Cloud tier (no card); Enterprise contact salesFreemium· Free personal; team from $50/mo per seat
ModelMulti-modelPlatform (any LLM)
Editorial score—8.4 / 10
Use cases
llm-tracingagent-evaluationprompt-testingproduction-monitoringguardrailscost-tracking
ML experimentsLLM evalWeave
Pros
  • Fully open-source with permissive self-hosting
  • 30+ built-in LLM-as-a-Judge evaluation metrics
  • Broad SDK and framework integrations (LangChain, LlamaIndex, LiteLLM, CrewAI)
  • Production guardrails plus PII protection out of the box
  • Free Cloud tier with no credit card required
  • Industry-standard for ML tracking
  • Weave adds LLM-native eval
  • Mature, reliable
  • Strong enterprise features
Cons
  • Feature surface area is wide; non-trivial onboarding
  • Self-hosting at scale still requires real infra work
  • Ollie auto-fix agent is newer and less battle-tested
  • Cost dashboard is most useful if you're already on Claude Code
  • Heavier UX than LLM-native tools
  • LLM features still catching up
Websitecomet.comwandb.ai
Pick Opik if
  • ✅ Fully open-source with permissive self-hosting
  • ✅ 30+ built-in LLM-as-a-Judge evaluation metrics
  • ✅ Broad SDK and framework integrations (LangChain, LlamaIndex, LiteLLM, CrewAI)
  • ✅ Production guardrails plus PII protection out of the box
Pick Weights & Biases if
  • ✅ Industry-standard for ML tracking
  • ✅ Weave adds LLM-native eval
  • ✅ Mature, reliable
  • ✅ Strong enterprise features
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