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.
Parea AI provides evaluation, testing, and observability for LLM applications.
What each tool does well, and the limitations to keep in mind.
Pros
Cons
Pros
Cons
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.