A agentindex
Comparison

Arize Phoenix vs Patronus AI

A like-for-like, spec-level comparison. Both entries are verified against their docs and repo.

Arize Phoenix

Open-source LLM tracing and eval.

  • + Open source with OTel foundations
  • + Good LLM-as-a-judge evals built in
  • − Elastic license restricts some hosted offerings
  • − Enterprise features in the paid Arize cloud

Patronus AI

Automated evaluation and guardrails for LLMs.

  • + Research-backed evaluation benchmarks
  • + Strong for enterprise compliance
  • − Proprietary and enterprise-priced
  • − Not a general observability tool
Spec Arize Phoenix Patronus AI
Category eval-observability eval-observability
License Elastic-2.0 Proprietary
Open source Yes No
Self-hostable Yes No
MCP support No No
Pricing free paid
Starting price Self-host free Custom
Models multi multi
Languages python, typescript python
GitHub stars 10.3k —
Last activity 2026-06-25 —