Arize AI vs Lunary
Updated March 10, 2026
Overview
Arize AI provides an ML and LLM observability platform for monitoring model performance in production. For LLM applications, Arize offers trace visualization, prompt analysis, embedding drift detection, and retrieval evaluation. Their open-source Phoenix library provides local tracing and evaluation. Arize helps teams identify quality issues, debug failures, and continuously improve AI system performance.
Lunary is an open-source LLM observability platform for monitoring AI applications in production. It provides request tracing, cost tracking, user analytics, and prompt management with a clean dashboard. Lunary can be self-hosted for data privacy and offers a managed cloud option.
Key features
Core capabilities each platform advertises.
- ML observability with LLM support
- Embedding drift detection
- Performance dashboards
- Automatic monitors and alerts
- Open-source Phoenix companion
Strengths and tradeoffs
What each tool does well, and the limitations to keep in mind.
Pros
- Built on OpenTelemetry standards ensuring interoperability and avoiding vendor lock-in
- Impressive scale with 1 trillion spans processed and 5 million monthly OSS downloads
- Open-source Phoenix OSS option available for self-hosting
- Enterprise-proven with major clients like DoorDash, Instacart, Reddit, and Uber
- Comprehensive platform covering development, debugging, evaluation, and production monitoring
Cons
- Enterprise pricing starting at ~$1,000/month may be prohibitive for smaller teams
- Complexity of full feature set may require longer onboarding and learning curve
- Less transparent pricing compared to competitors with clear tier structures
Pros
- Production-ready platform
- Good performance
- Active development
- Strong features
Cons
- Enterprise pricing varies
- Setup complexity
- Learning curve required
Arize AI or Lunary — which should you choose?
Choose Arize AI if you wantChoose if you want
- Production ML and LLM monitoring
- Embedding quality monitoring
- Model performance tracking
- Drift detection for AI systems
- Root cause analysis for AI failures
Choose Lunary if you wantChoose if you want
Compare Arize AI and Lunary 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.