Opik vs Phoenix

Both platforms offer open-source AI observability with tracing and LLM-as-a-judge evaluation, but differ in their core philosophy and tooling. Phoenix is built on OpenTelemetry standards making it truly vendor-agnostic across any language or framework, emphasizing a complete iteration workflow from tracing through experimentation. Opik differentiates with its AI coding assistant (Ollie) that suggests automated code fixes, plus production-focused features like guardrails and more extensive pre-built evaluation metrics (30+). Choose Phoenix for maximum portability and standards-based integration, or Opik for richer out-of-the-box evaluation options and AI-assisted debugging.