📖 The AI Tool Bible

Braintrust vs Langfuse

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

 
Braintrust
Evaluation
Langfuse
Evaluation
TaglineEval, monitor, and improve AI products end-to-end.Open-source LLM observability, prompt management, and evaluation in one platform.
CategoryEvaluationEvaluation
PricingFreemium· Free up to 1k events/day; team from $249/moFreemium· Free self-host & Hobby tier; Core $29/mo, Pro $199/mo, Enterprise $2,499/mo
ModelPlatform (any LLM)Model-agnostic
Editorial score8.9 / 10—
Use cases
evalsmonitoringprompt management
llm-observabilityprompt-managementllm-evaluationagent-tracingrag-debugging
Pros
  • Full eval + observability in one tool
  • Excellent UX
  • Strong dataset/experiment tracking
  • Closed loop dev → prod
  • Fully open source and self-hostable at no cost
  • Tracing, prompts, and evals in one platform instead of three
  • Built on OpenTelemetry with SDKs for Python and JS
  • Integrates with OpenAI SDK, LangChain, LlamaIndex, and 100+ libraries
  • Generous free Hobby tier with no credit card required
Cons
  • Team pricing is steep
  • Smaller than LangSmith ecosystem-wise
  • Cloud pricing by 'units' is opaque until you instrument and measure
  • Self-hosting Postgres + ClickHouse stack is non-trivial to operate
  • Pro/Enterprise jump ($29 to $199 to $2,499) leaves a gap for mid-size teams
Websitewww.braintrust.devlangfuse.com
Pick Braintrust if
  • ✅ Full eval + observability in one tool
  • ✅ Excellent UX
  • ✅ Strong dataset/experiment tracking
  • ✅ Closed loop dev → prod
Pick Langfuse if
  • ✅ Fully open source and self-hostable at no cost
  • ✅ Tracing, prompts, and evals in one platform instead of three
  • ✅ Built on OpenTelemetry with SDKs for Python and JS
  • ✅ Integrates with OpenAI SDK, LangChain, LlamaIndex, and 100+ libraries
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