Updated March 10, 2026
Fiddler AI is an enterprise platform for observing, evaluating, and governing AI agents and ML models, with guardrails that run in your own environment.
Martian is an intelligent model router that automatically selects the best LLM for each request based on the prompt content, required capabilities, and cost constraints. Using proprietary routing models, Martian optimizes for quality and cost simultaneously, helping teams reduce LLM spend while maintaining or improving output quality.
Core capabilities each platform advertises.
What each tool does well, and the limitations to keep in mind.
Pros
Cons
Pros
Cons
Choose Fiddler AI if you wantChoose if you want
Choose Martian if you wantChoose if you want
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.
Try Respan free