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 provides comprehensive LLM observability with real-time monitoring, tracing, and debugging for AI applications in production. It tracks prompts, completions, latency, cost, and quality metrics across all LLM providers, with built-in evaluation tools, prompt management, and alerting. Respan gives engineering teams full visibility into their AI stack from a single dashboard.
What each tool does well, and the limitations to keep in mind.
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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.