What is Arize AI
Arize provides AI observability and evaluation through the open-source Phoenix project and the commercial Arize AX platform.
Plans
As of September 9, 2026, Phoenix is free and open source, with user-managed hosting, trace volume, projects and retention. AX Free costs US$0 and includes 25,000 trace spans and 1GB of ingestion per month, 15-day retention, unlimited users and evaluations, ten Signal issue investigations per month, the Alyx agent, online evaluations, production monitoring and community support.
AX Pro costs US$50 per month and includes 50,000 spans, 10GB of ingestion, 30-day retention, unlimited users and evaluations, 25 Signal issue investigations per month, higher rate limits and email support. AX Enterprise uses custom pricing and can run as SaaS or self-hosted with configurable limits and retention, bring-your-own or managed model keys, dedicated support, SLA, SOC 2 and HIPAA materials, training, data residency and multi-region deployment. Arize's current public page does not publish a numeric overage rate.
Buying notes
Self-hosted Phoenix has no Arize software subscription fee but leaves infrastructure and operations to the user. Arize also offers a separately quoted dedicated-support add-on for Phoenix.
Official source: Arize pricing.