Arize Phoenix alternatives
Phoenix is free and self-hostable, its licence is not what most people think, and Dynatrace has owned Arize since October 2026.
Phoenix is a genuinely good local tool for tracing and evaluating LLM applications. You can run it with one command and it costs nothing. Start there before reading the rest of this page.
Two facts that are usually reported wrong
The licence is the Elastic License 2.0, not Apache. Its central restriction is that you may not offer the software to third parties as a hosted or managed service.
For almost everyone that restriction never bites. It matters if you intended to resell it, and it means Phoenix is source-available rather than open source in the OSI sense. GitHub itself does not classify the licence.
The second fact is newer. Dynatrace completed its acquisition of Arize on 1 October 2026. The announcement says Phoenix and the commercial platform both continue, and that Arize capabilities will be folded into Dynatrace over time.
Phoenix and AX are different products
| Phoenix | Arize AX | |
|---|---|---|
| Cost | Free, self-hosted | Free tier, then 50 dollars a month, then custom |
| Licence | Elastic License 2.0 | Commercial |
| Spans included | Your own machine | 25,000 then 50,000 a month |
| Retention | Yours | 15 days, then 30 days |
| Self-hosting | Yes, that is the point | Enterprise tier only |
AX does carry multi-modal evaluation including voice, and evaluation across multi-turn sessions, on every tier. Anyone telling you Arize has no voice story is describing Phoenix and calling it Arize.
Where we are different
Both products are built on OpenTelemetry, so something in your code emits a span. That is the right design for an application you wrote and the wrong one for traffic you did not.
| Phoenix and AX | Evidova | |
|---|---|---|
| Built around | A span, via OpenTelemetry | A conversation, via the platform's webhook |
| Instrumentation | You add it to your code | None |
| Run it yourself | Phoenix, yes | No |
| Judge agreement | Not published per customer | Measured per workspace and published |
If you want a free tool on your own machine with no vendor at all, Phoenix is the best answer in this category and we are not competing for that.
Everything above was read on each company's own site and documentation on 5 October 2026. Pricing and features move. Check the source before you make a decision on it, and tell us if we have something wrong.
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