Updated March 10, 2026
Opik by Comet is an open-source LLM evaluation and observability platform. It provides tracing, evaluation scoring, dataset management, and experiment tracking for LLM applications. Opik supports automated LLM-as-judge evaluations and integrates with popular frameworks like LangChain and LlamaIndex.
Respan is LLM observability built into an AI router: nested traces for every agent run, evals on live production traffic, and a click from any score to its trace.
Core capabilities each platform advertises.
What each tool does well, and the limitations to keep in mind.
Pros
Cons
Pros
Cons
Choose Opik if you wantChoose if you want
Choose Respan 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.
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