Both Prefactor and Arize Phoenix give you visibility into your LLM agents. They take different approaches and serve different stages of maturity. This page is for the buyer with both vendors open in tabs trying to decide.
Quick decision
Pick Prefactor if you need:
- Runtime policy enforcement (block, route, approve)
- Audit-grade logs for SOC 2 / ISO 42001 / EU AI Act
- A unified governance layer across multiple agent frameworks
- An agent-shaped data model with owners, environments, lifecycle
- Enterprise procurement readiness
Pick Arize Phoenix if you need:
- Strong OpenTelemetry foundation
- Excellent eval harness with LLM-as-judge templates
- Backed by Arize AI's serious ML observability engineering
Feature-by-feature
Observability
| Prefactor | Arize Phoenix | |
|---|---|---|
| Trace capture | Supported | Supported |
| Multi-framework unified | Supported | Per-integration |
| Per-agent cost attribution | Native | Manual tagging |
Policy & enforcement
| Prefactor | Arize Phoenix | |
|---|---|---|
| Block tool calls in real time | Supported | Not in core product |
| Approval routing | Supported | Not in core product |
| Policy-as-code | Supported | Not in core product |
Audit & compliance
| Prefactor | Arize Phoenix | |
|---|---|---|
| Tamper-evident logs | Supported | Application-level |
| Pre-mapped compliance | SOC 2, EU AI Act, ISO 42001, HIPAA, NIST AI RMF | Bring-your-own |
| Auditor-ready exports | Supported | DIY |
Enterprise
| Prefactor | Arize Phoenix | |
|---|---|---|
| SSO / SAML | Supported | Paid tier |
| SCIM | Business+ | Roadmap or Enterprise |
| Self-hosted | Business+ | Yes |
| SOC 2 Type II | Supported | Supported |
Pricing
Arize Phoenix: Free (self-hosted); Arize platform pricing custom
Prefactor: Free 10k traces/month, Team from $499/mo, Business/Enterprise custom
Pricing as of May 2026. Verify against current pricing pages.
FAQ
Can I run both at the same time? Yes. They don't conflict.
Is Prefactor more expensive? Depends on scale. Per-agent pricing scales better than per-event pricing at enterprise.
Will Arize Phoenix add the missing capabilities? Verify their public roadmap.
Get started
[Try Prefactor free →] [Book a comparison demo →]