Helicone vs PromptLayer
Updated March 10, 2026
Overview
Helicone is an open-source LLM observability and proxy platform. By adding a single line of code, developers get request logging, cost tracking, caching, rate limiting, and analytics for their LLM applications. Helicone supports all major LLM providers and offers both proxy and async logging modes. Popular with startups for its generous free tier and simple integration.
PromptLayer is a prompt management platform that provides version control, monitoring, and collaboration tools for LLM prompts. It logs every LLM request, tracks prompt templates, enables A/B testing across prompt versions, and provides a visual dashboard for prompt performance analytics.
Strengths and tradeoffs
What each tool does well, and the limitations to keep in mind.
Pros
- Open-source with 5.2K GitHub stars and strong community support
- Minimal latency overhead (under 1ms for self-hosted)
- Flexible deployment options including cloud-hosted, self-hosted, or SDK-only
- Y Combinator-backed with SOC 2 Type II and HIPAA compliance
- No code changes required for AI Gateway features like caching and rate limiting
Cons
- Adds computational cost and one network hop for cloud deployment
- Limited pricing transparency on website
- May require infrastructure expertise for self-hosted setup
Pros
- Production-ready
- Good performance
- Active development
Cons
- Pricing varies
- Setup required
Compare Helicone and PromptLayer on your own traffic
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 500+ models through one gateway.