📖 The AI Tool Bible

Braintrust vs Respan (formerly Keywords AI)

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

 
Braintrust
Evaluation
Respan (formerly Keywords AI)
Evaluation
TaglineEval, monitor, and improve AI products end-to-end.LLM engineering platform combining a multi-model gateway with tracing, evals, and prompt management.
CategoryEvaluationEvaluation
PricingFreemium· Free up to 1k events/day; team from $249/moFreemium· Free tier; paid plans (pricing not public); enterprise on request
ModelPlatform (any LLM)Multi-model (500+ via gateway)
Editorial score8.9 / 10—
Use cases
evalsmonitoringprompt management
llm-observabilityprompt-managementmodel-routingevalsproduction-monitoring
Pros
  • Full eval + observability in one tool
  • Excellent UX
  • Strong dataset/experiment tracking
  • Closed loop dev → prod
  • Unified gateway to 500+ models with fallback and error handling
  • End-to-end loop: trace, evaluate, monitor, version prompts in one UI
  • Eval system mixes rules, AI judges, and human review
  • Broad SDK and framework coverage (LangChain, LlamaIndex, Vercel AI SDK)
  • YC-backed with serious production scale (80T+ tokens claimed)
Cons
  • Team pricing is steep
  • Smaller than LangSmith ecosystem-wise
  • Closed source — no self-host option for most customers
  • Paid pricing not transparent on the site
  • Recent rebrand from Keywords AI may cause doc and link churn
  • Gateway dependency adds a network hop and vendor lock-in
Websitewww.braintrust.devwww.respan.ai
Pick Braintrust if
  • ✅ Full eval + observability in one tool
  • ✅ Excellent UX
  • ✅ Strong dataset/experiment tracking
  • ✅ Closed loop dev → prod
Pick Respan (formerly Keywords AI) if
  • ✅ Unified gateway to 500+ models with fallback and error handling
  • ✅ End-to-end loop: trace, evaluate, monitor, version prompts in one UI
  • ✅ Eval system mixes rules, AI judges, and human review
  • ✅ Broad SDK and framework coverage (LangChain, LlamaIndex, Vercel AI SDK)
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