Skip to main content
📖 The AI Tool Bible

Arize AI vs Fiddler AI

A side-by-side look at pricing, capabilities, pros, cons, and our editorial scores.

Arize AI logo
Arize AI
Evaluation
Fiddler AI logo
Fiddler AI
Evaluation
Tagline
Arize AI
Enterprise observability and evaluation platform for LLM agents and generative AI applications.
Fiddler AI
Enterprise AI observability and guardrails platform for monitoring agents, LLMs, and ML models in production.
Pricing
Arize AI
Freemium· AX Free: Free · AX Pro: $50 · AX Enterprise: Custom
Fiddler AI
Enterprise· Free: Free · Developer: $0.002 per trace · Enterprise: Contact sales
Lowest paid tier
Arize AI
$50 · AX Pro
captured 2026-08-08
Fiddler AI
$0.002 per trace · Developer
captured 2026-08-10
Free trial
Arize AI
Yes
Fiddler AI
Not listed
API
Arize AI
Yes
Fiddler AI
Yes
Platforms
Arize AI
api
Fiddler AI
api
Open source
Arize AI
Yes
Fiddler AI
Not listed
Model used
Arize AI
Multi-model
Fiddler AI
Fiddler Centor (proprietary evaluators)
Best for
Arize AI
Pick Arize if you're running LLM agents or RAG in production and need real tracing, evals, and regression testing rather than ad-hoc logging.
Fiddler AI
Pick Fiddler AI if you are deploying LLM agents in a regulated enterprise and need observability, guardrails, and auditable governance in a single platform.
Not for
Arize AI
Skip it if you're a solo builder shipping a side project; the OSS Phoenix tool alone will likely cover your needs.
Fiddler AI
Skip it if you are an indie developer or startup who just wants free LLM tracing and basic eval dashboards.
Editorial score
Arize AI
8.2 / 10
Fiddler AI
7.1 / 10
Use cases
Arize AI
llm-observabilityagent-evaluationrag-tracingprompt-testingproduction-monitoring
Fiddler AI
llm-observabilityagent-monitoringai-guardrailsmodel-governancehallucination-detectioncompliance
Pros
Arize AI
  • Strong open-source story via Phoenix and OpenInference
  • Span/trace/session-level evals tuned for agentic workflows
  • Scales to trillions of spans with enterprise compliance (SOC 2, HIPAA, GDPR)
  • Broad framework coverage: LangGraph, LangChain, CrewAI, OpenAI, Anthropic
  • Self-hosted option for regulated deployments
Fiddler AI
  • Purpose-built for regulated industries with deep governance and audit features
  • Inline guardrails enforce policy in real time on request/response paths
  • Proprietary Centor evaluator models reduce LLM-as-judge cost
  • Covers agents, LLMs, and classical ML in one control plane
Cons
Arize AI
  • Public pricing is opaque; serious usage means a sales call
  • Feature surface is heavy for solo developers or hobby projects
  • Best value assumes you've standardized on OpenInference tracing
Fiddler AI
  • Enterprise sales motion; no transparent self-serve pricing
  • Closed source with limited public technical detail
  • Overkill for solo developers or small AI projects
  • Setup and integration overhead vs. lightweight tracing tools
Website
Arize AI
arize.com
Fiddler AI
fiddler.ai

Editorial score: rule-based, 0–10, from AI-assisted profile inputs (see /methodology) — not a user rating; “—” means unscored. “Not listed” means we have no record of it, not that it is absent. GitHub figures and prices carry the date they were checked or captured; prices are shown as published, unconverted.

Pick Arize AI if
  • ✅ Strong open-source story via Phoenix and OpenInference
  • ✅ Span/trace/session-level evals tuned for agentic workflows
  • ✅ Scales to trillions of spans with enterprise compliance (SOC 2, HIPAA, GDPR)
  • ✅ Broad framework coverage: LangGraph, LangChain, CrewAI, OpenAI, Anthropic
Pick Fiddler AI if
  • ✅ Purpose-built for regulated industries with deep governance and audit features
  • ✅ Inline guardrails enforce policy in real time on request/response paths
  • ✅ Proprietary Centor evaluator models reduce LLM-as-judge cost
  • ✅ Covers agents, LLMs, and classical ML in one control plane
Compare a different pair →