Opik
Open-source LLM evaluation, tracing, and monitoring platform
About Opik
Opik by Comet is an open-source platform for debugging, evaluating, and monitoring LLM applications, RAG systems, and agentic workflows. It provides comprehensive tracing with cost tracking, built-in evaluation metrics for hallucination and relevance detection, prompt version management, and production-ready dashboards — available as both a self-hosted solution and managed cloud service.
Pros & Cons
Pros
- Fully open-source with the complete feature set available for free self-hosting
- Comprehensive evaluation metrics cover hallucination, relevance, moderation, and custom criteria
- LLM-as-a-Judge enables automated quality evaluation at scale
- Prompt version management brings engineering rigor to prompt development
- Production monitoring dashboards provide real-time visibility into LLM costs and performance
- Broad framework integrations work with LangChain, LlamaIndex, OpenAI, and more
Cons
- Part of the broader Comet ML ecosystem — may feel heavy for teams only needing LLM eval
- Self-hosted deployment requires infrastructure setup and maintenance
- Newer product compared to established observability tools like Langfuse or Arize
- Documentation and community are still growing
- Some advanced features like Agent Optimizer are still evolving
Key Features
LLM Tracing
Deep tracing of LLM calls, conversation flows, and agent activity with cost tracking and latency metrics
Evaluation Metrics
Built-in metrics for hallucination detection, content moderation, answer relevance, and factual accuracy
LLM-as-a-Judge
Use LLMs to automatically evaluate output quality with customizable evaluation criteria and rubrics
Prompt Management
Version control for prompts with A/B testing, comparison tools, and rollback capabilities
Experiment Tracking
Run and compare evaluation experiments across different models, prompts, and configurations
Production Monitoring
Real-time dashboards for monitoring LLM performance, costs, and quality metrics in production
Agent Optimizer SDK
Automated prompt tuning and optimization for improving LLM application performance
Framework Integrations
Native support for LangChain, LlamaIndex, OpenAI, and other popular LLM frameworks
Pricing
- Full feature set
- Self-hosted
- Community support
- Unlimited team members
- Open-source
- Managed hosting
- Unlimited team members
- Basic storage
- Community support
- Everything in Free
- Extended storage
- Priority support
- Advanced analytics
- SSO
- Custom hosting
- Advanced identity management
- Dedicated support
- Custom SLA
- Compliance features
Best For
LLM Application Development
Debug and iterate on LLM-powered features with comprehensive tracing and evaluation during development
RAG Quality Assurance
Evaluate retrieval-augmented generation pipelines for relevance, accuracy, and hallucination rates
Production LLM Monitoring
Monitor live LLM applications for cost, latency, quality degradation, and content safety in real-time
Prompt Engineering
Manage prompt versions, run A/B tests, and systematically optimize prompts with experiment tracking
Agent Evaluation
Trace and evaluate complex agentic workflows to identify bottlenecks and improve agent reliability
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Featured In
7 Best AI Benchmark & Model Comparison Tools for Choosing the Right LLM (2026)
Best open-source option for teams that want rigorous, reproducible model evaluations. The built-in metrics and LLM-as-a-Judge make it possible to compare models on your specific quality dimensions without building custom evaluation pipelines.
7 Tools That Prevent AI Hallucinations in Customer-Facing Content (2026)
Best open-source option for teams that want dedicated hallucination metrics without paying for a SaaS platform