Agentic Index
Arize Ai vs Wandb Weave (2026)
Two observability platforms with open source at the core, and the split is whose ecosystem you are joining.
Arize traces, evaluates and monitors LLM applications with Phoenix as its open source core, from 50 dollars a month with a free tier, documenting 7.5 of 14. Weave brings the same job inside Weights and Biases, with session aware tracing and LLM as a judge scoring, free then about 60 dollars a month plus usage meters. Very close on capability, so decide on where the rest of your stack already sits.
Choose Arize Ai if
- Phoenix as an open source core matters: you want to run it yourself or read the code.
- Documented coverage is slightly broader, and you want the most complete option of the two.
- You are not a Weights and Biases shop and prefer a tool that does not assume you are.
Choose Wandb Weave if
- Your models are already tracked in Weights and Biases and one pane of glass wins.
- Safety scorers and guardrails alongside evaluation are part of the requirement.
- Usage metered pricing on top of a low base fits variable traffic better than a per month floor.
Vendor data for this comparison is unavailable.
Browse the full vendor directory