📖 The AI Tool Bible

Helicone vs PromptLayer

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

 
Helicone
Evaluation
PromptLayer
Evaluation
TaglineOpen-source LLM observability — one-line proxy install.Lightweight prompt logging + management for OpenAI/Claude apps.
CategoryEvaluationEvaluation
PricingFreemium· Free 100k req/mo; Pro from $25/moFreemium· Free; Pro from $50/mo
ModelPlatform (any LLM)Platform (any LLM)
Editorial score8.3 / 107.9 / 10
Use cases
observabilitycost trackingopen source
prompt loggingversioningsmall teams
Pros
  • One-line install
  • Open source
  • Generous free tier
  • Cost tracking is genuinely useful
  • Easiest to drop in
  • Good free tier
  • Decent prompt versioning
  • Affordable Pro tier
Cons
  • Eval features less deep than Braintrust
  • Proxy adds a hop
  • Eval/dataset features less deep than Braintrust
  • Less observability
Websitewww.helicone.aiwww.promptlayer.com
Pick Helicone if
  • ✅ One-line install
  • ✅ Open source
  • ✅ Generous free tier
  • ✅ Cost tracking is genuinely useful
Pick PromptLayer if
  • ✅ Easiest to drop in
  • ✅ Good free tier
  • ✅ Decent prompt versioning
  • ✅ Affordable Pro tier
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