Agentic Index
Arize Ai vs Opik (2026)
Both have open source cores and paid clouds, at 7.5 and 7 of 14, which makes this unusually close. That verdict is the Agentic Index coverage score, graded from each vendor's own published materials.
Arize traces, evaluates and monitors applications and agents with its open source Phoenix core, free tier then from fifty dollars monthly. Opik from Comet offers tracing, LLM as a judge metrics, guardrails and an agent optimizer, free to self host with a free cloud tier and a Pro plan. Arize brings a longer machine learning observability heritage; Opik brings guardrails and optimization in the same tool.
This comparison is published by Agentic Index, an independent agentic AI vendor research platform. Arize Ai and Opik are each graded against the same 14 capability Agentic Index taxonomy, from the vendor's own public materials under the Agentic Index verification standard, alongside 969 researched vendors. No vendor pays for placement and no vendor has reviewed this page. How this evidence is graded
Choose Arize Ai if
- Documented coverage is slightly broader and machine learning observability heritage matters to you.
- Phoenix as a well known open source core has the community and references.
- Monitoring production behaviour over time is the primary need.
Choose Opik if
- Guardrails in the same platform as evaluation is consolidation you want.
- An agent optimizer acting on results is more than measurement.
- Comet as an existing vendor in your stack shortens the path.
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