Arize Pricing in 2026 - Phoenix Is Free, AX Is a Sales Call

The first thing to know about Arize pricing is that “Arize” is two products, and only one of them has a price you can read. Phoenix is the free open-source tracer. Arize AX is the separate managed platform, and its pricing is a sales call. Get that split straight and the rest is simple.

When people say “Arize,” they usually mean Phoenix - the tool that runs locally on your laptop in under a minute. But the company also sells Arize AX, a quote-based managed cloud built by the same team. They are priced nothing alike. Here is how to tell which one you are actually pricing.

The two products, side by side

Product	Price	What you get
Phoenix (OSS)	$0	Self-host, unlimited spans, all features, ELv2 server
Arize AX	Contact sales	Managed cloud, longer retention, collaboration, support
Arize AX Enterprise	Contact sales	Custom retention, SSO, enterprise support

Phoenix is genuinely free. You self-host it with no usage caps and no feature gates on the features themselves - tracing, evals, datasets, experiments and the prompt playground are all in. It ships 50+ pre-built eval metrics, including what reviewers call the best RAG evaluation in the category. You pay only for the infrastructure you run it on. For a lot of teams, that is the entire pricing conversation, and it ends at zero.

There is one asterisk on “free,” and it is about the license, not the money. The main Phoenix server repo is Elastic License 2.0 - source-available, not OSI-approved open source. ELv2 forbids offering Phoenix as a hosted or managed service to third parties. Only the client and eval subpackages (phoenix-evals, phoenix-client, phoenix-otel) are Apache-2.0. For internal use it behaves like open source and nothing is gated. But if your business model is reselling it as a service, the license rules it out. Arize’s “fully open source, no feature gates” marketing overstates that - the features are not gated, the license is.

Arize AX: the price you cannot look up

Here is where “arize pricing” gets frustrating. The arize.com pricing page was unreadable at our verification - it returned an HTTP 403 - so there are no vendor-confirmed AX figures.

Third-party aggregators report an AX Pro tier around $50/mo and a free tier metered in spans per month, but those numbers are unconfirmed and I am not going to hand them to you as fact. Treat AX pricing as contact-sales until Arize publishes it. What we can say is that AX bills in spans per month, not seats or traces, and it adds managed hosting, longer retention, collaboration and support on top of what Phoenix already does for free.

So the honest framing: you cannot forecast an AX bill from public information. If AX is on your shortlist, budget a sales call and get the quote in writing. The company itself is well-funded and stable - Arize raised a $70M Series C in February 2025, per its own announcement - so this is not a survival question. It is a transparency one.

How to price your own Phoenix deployment

Since Phoenix is the free path most teams take, here is the realistic cost model. The software is $0. Your bill is infrastructure plus operations.

Phoenix runs locally in under a minute for development, which costs nothing. For a shared production deployment you run it on your own compute - a container, some storage for spans, and whatever retention you want, since there are no usage caps. There is a known trade-off worth pricing in: reviewers report ingest lag, a noticeable delay before traces appear, tied to the bulk-inserter path. That is an engineering cost if real-time visibility matters, not a dollar cost.

The unpriced item is your team’s time. Self-hosting means you own upgrades, scaling and uptime. For a small team that runs Phoenix internally, the license restriction never bites and the total cost really is close to just the box it runs on.

If AX is the answer, price these instead

If what you actually want is managed hosting without a sales call - the thing AX sells - two tools give you that with published pricing.

Opik is the cheapest managed cloud in the category. Pro is $19/mo for 100k spans, with a published $5 per additional 100k, and the free cloud tier gives you 25k spans a month. Opik is Comet’s platform and, like Phoenix, self-hosts - but under Apache-2.0, the more permissive license, with the full feature set and no ELv2 restriction. The honest gotcha is per-seat pricing that scales poorly as your team grows, so model the seat cost if you are big. But the rate is on the page, which is the whole point.

Langfuse is the transparent open-source default. Its Core tier is $29/mo for 100k billable units, then a published $8 per 100k, and it self-hosts free under MIT - genuinely OSI open source, unlike Phoenix’s ELv2 server. At 1M events a month it runs about $101/mo managed, per Langfuse’s pricing. The self-host catch is operational: v3 needs Postgres plus ClickHouse, Redis and S3-compatible storage. But every number is public, and if OSI open source is a hard requirement, Langfuse clears a bar Phoenix does not.

So which one?

• You want free tracing and the best RAG eval, run internally - Phoenix. It is free with no caps, and the license only bites if you plan to resell it as a service.
• You are pricing Arize AX - budget a sales call. The public pricing page is unreadable and the third-party numbers are unconfirmed.
• You want managed hosting with published pricing - Opik at $19/mo for 100k spans, or Langfuse at $29/mo for 100k units.
• You need OSI-approved open source specifically - Langfuse under MIT, not Phoenix’s ELv2 server.

One honest note. Phoenix’s free status and the Langfuse and Opik prices are from each vendor’s public materials. Arize AX pricing is flagged as unconfirmed because the vendor page returned a 403 and the third-party figures are not verifiable. This category ships breaking changes monthly - we re-verify every 30 days. If a price you cannot look up is a dealbreaker, that alone points you at the transparent alternatives.