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Pydantic Logfire vs Arize Phoenix: catalog facts
Pydantic Logfire	Arize Phoenix
Freemium Free for 10 million spans, logs and metrics per month, no card required; paid plans above…	Freemium Phoenix is free to self-host; Arize AX is a separate managed paid platform.
Web	Web, Self-hosted
Traces LLM calls alongside API and database activity Built on OpenTelemetry with SQL querying	Tracing, evals, prompts and experiments in one tool Runs locally, in Docker or on Kubernetes
Primarily a hosted service requiring an account Self-hosting is offered as an option rather than the default	Source-available license rather than an OSI-approved one Some advanced features are in the separate paid Arize AX product
Web application, Hosted service	Self-hosted, Hosted service
Closed source	Closed source
License not stated	License: Elastic-2.0
Account needed	Not stated if an account is needed
Needs internet	Not stated if it works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked September 26, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.