PromptLayer
Lightweight prompt logging + management for OpenAI/Claude apps.
PromptLayer is the easy-on-ramp for prompt logging and management — drop-in middleware that tracks every LLM call, version your prompts, and run simple evals.
Pros
- ✅ Easiest to drop in
- ✅ Good free tier
- ✅ Decent prompt versioning
Cons
- ⚠️ Eval/dataset features less deep than Braintrust
- ⚠️ Less observability
Use cases
prompt loggingversioningsmall teams
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PromptLayer vs Braintrust
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PromptLayer vs Weights & Biases
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Braintrust
FeaturedEvaluation
8.9
Eval, monitor, and improve AI products end-to-end.
Freemium· Free up to 1k events/day; team from $249/moevalsmonitoring
LangSmith
Evaluation
8.7
LangChain's eval + observability platform.
Freemium· Free starter; Plus $39/mo per seatLLM tracingevals
Weights & Biases
Evaluation
8.4
The ML experiment tracker, now with LLM eval features.
Freemium· Free personal; team from $50/moML experimentsLLM eval
Helicone
Evaluation
8.3
Open-source LLM observability — one-line proxy install.
Freemium· Free 100k requests/mo; from $25/moobservabilitycost tracking
Humanloop
Evaluation
8.2
Prompt management + evals for collaborative AI teams.
Paid· From $200/mo teamprompt managementteam collab
Patronus
Evaluation
7.8
Automated LLM evaluation for hallucinations, safety, and quality.
Paid· Enterprise pricinghallucination detectionsafety