Arize Phoenix
Arize Phoenix: A free platform for tracing, evaluating, and improving LLM applications. Ranked #3 of 26 in LLM Observability Tools by our editors (9.2/10); pricing: Free plan; best for developers wanting free open-source LLM observability.
At a glance
- Editor score9.2 / 10
- PricingFree plan
- Best forDevelopers wanting free open-source LLM observability
- Free planYes
- Paid fromFree
- LLM tracingYes
- Facts checked20 Sep 2026
Where it wins
- Free open-source plan with tracing, evaluations, and prompt iteration
- Tracks retrieval, tool use, prompts, experiments, and token-based costs
- Supports web, API, self-hosted deployment and multiple AI frameworks
Where it doesn't
- Focused on AI applications and agents rather than general observability
- Instrumentation coverage centers on Python, TypeScript, and Java
- Hosted Phoenix Cloud is distinct from local-first and self-hosted use
Our verdict on Arize Phoenix
Arize Phoenix is an open-source observability and evaluation platform for AI applications and agents. It is designed for developers who need visibility into model calls, retrieval, tool use, and custom application logic. The platform combines tracing with LLM-based, code-based, and human evaluations, while also covering prompt versioning, experiments, datasets, replay, and cost tracking. Phoenix is available through web and API access, can run locally or be self-hosted, and supports instrumentation through OpenTelemetry and OpenInference.
The free Phoenix plan provides the core platform without a paid-tier split: the published plan is priced at $0 and includes an open-source, local-first platform for tracing, evaluation, experimentation, and prompt iteration. Its feature set extends beyond basic request logs. Teams can inspect retrieval and tool-use traces, attach human annotations and labels, compare datasets and experiments, replay spans, manage prompt versions, and monitor token-based costs. This makes Phoenix a strong fit for teams that want a broad development and evaluation workflow without a separate license fee for these capabilities.
Ecosystem coverage is a notable consideration. Phoenix integrates with OpenAI, Anthropic, Amazon Bedrock, LlamaIndex, LangChain, DSPy, Mastra, and the Vercel AI SDK, with instrumentation support for Python, TypeScript, and Java. That range suits teams building across common model providers and agent frameworks. Its focus is specifically AI applications and agents, so teams seeking general-purpose software observability should look elsewhere. Choose Phoenix when open-source deployment, tracing depth, evaluations, prompt workflows, and retrieval or tool-use visibility matter most; choose an alternative when your observability needs extend beyond AI systems.
Your product? Our editors can test Arize Phoenix in depth and publish a review, labelled as paid · from $149/mo →
Arize Phoenix pricing
All 1 Arize Phoenix plans and prices →
Arize Phoenix fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| LLM tracing | Yes |
| LLM evaluations | Yes |
| Prompt management | Yes |
| Agent tracing | Yes |
| Retrieval tracing | Yes |
| Token cost tracking | Yes |
| Deployment options | Both |
| Deployment | Cloud, Self-hosted |
| Platforms | Web |
| Support | Community, Docs |
| Built for | Solo, Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 11 integrations: OpenAI, Anthropic, Amazon Bedrock, LlamaIndex, LangChain, DSPy … |
| Pricing | Free plan (source) |
| Website | arize.com |
| Facts checked | 20 Sep 2026 |
Arize Phoenix integrations
Arize Phoenix lists 11 integrations on its own site.
- OpenAI
- Anthropic
- Amazon Bedrock
- LlamaIndex
- LangChain
- DSPy
- Mastra
- Vercel AI SDK
- Python
- TypeScript
- Java
Alternatives to Arize Phoenix
- Arize AXBroad LLM observability with tracing, evaluations, prompts, agents, RAG, and cost tracking.9.4
- LangfuseA broad observability platform with open-source deployment and accessible paid tiers.9.3
- OpikA broad, cost-conscious stack for tracing, evaluation, prompts, monitoring, and agent debugging.9.1
See all Arize Phoenix alternatives →
Arize Phoenix vs the competition
- Arize Phoenix vs Arize AX
- Arize Phoenix vs Langfuse
- Arize Phoenix vs Opik
- Arize Phoenix vs W&B Weave
- Arize Phoenix vs LangSmith
- Arize Phoenix vs LangWatch
Compare Arize Phoenix with any tool side by side →
Also Ranked In
Arize Phoenix is ranked in 9 of our directories; the 6 strongest besides LLM Observability Tools.
Used Arize Phoenix? Be the first to review it
The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used Arize Phoenix for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.
Write a reviewTwo minutes · verified accounts only · read by an editor before it appears
Featured on iTechGuides
Arize Phoenix is listed in our LLM Observability Tools directory. Add the badge to your site — it links back to this page.
<a href="https://www.itechguides.com/products/arize-phoenix/"><img src="https://www.itechguides.com/best/badge/arize-phoenix.svg" alt="Featured on iTechGuides" width="230" height="46"></a>
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update