# Phoenix

Framework · https://godooo.ai/en/framework/phoenix

> Phoenix is an open-source AI framework, launched in 2022, made for developers and businesses.

An open-source tool for tracing, evaluating and debugging LLM apps and agents.

Main jobs: Evaluate and trace LLM apps. It is open source and free to use. You can use it on your own server, offline on your own machine, through an API and in the terminal.

## At a glance

- **Type:** [Framework](https://godooo.ai/en/browse#framework)
- **Launched:** 2022
- **Galaxy:** [Models & APIs](https://godooo.ai/en/galaxy/builders)
- **Open source:** Yes
- **Source code:** [github.com/Arize-ai/phoenix](https://github.com/Arize-ai/phoenix)
- **GitHub stars:** 11,600
- **How you run it:** Self-host · Runs offline · API · Terminal
- **Made for:** Developers · Businesses
- **Website:** [arize.com](https://arize.com/docs/phoenix)
- **Also known as:** Arize Phoenix

## What it can do

- **[Evaluate and trace LLM apps](https://godooo.ai/en/capability/llm-evaluation)** — main job, _proposed by a machine, awaiting calibration_. “Evaluation - Leverage LLMs to benchmark your application's performance using response and retrieval evals.” (read on [github.com](https://github.com/Arize-ai/phoenix), 2026-09-24)
- **[Prompt optimization](https://godooo.ai/en/capability/prompt-engineering)** — supported, _proposed by a machine, awaiting calibration_. “Playground - Optimize prompts, compare models, adjust parameters, and replay traced LLM calls.” (read on [github.com](https://github.com/Arize-ai/phoenix), 2026-09-24)

## Alternatives

- **[Langfuse](https://godooo.ai/en/product/langfuse)** (Open source, free): Also does: Evaluate and trace LLM apps, Prompt optimization
- **[DeepEval](https://godooo.ai/en/framework/deepeval)** (Open source, free): Also does: Evaluate and trace LLM apps
- **[promptfoo](https://godooo.ai/en/cli/promptfoo)** (Open source, free): Also does: Evaluate and trace LLM apps
- **[Ragas](https://godooo.ai/en/framework/ragas)** (Open source, free): Also does: Evaluate and trace LLM apps
- **[Pydantic AI](https://godooo.ai/en/framework/pydantic-ai)** (Open source, free): Also does: Evaluate and trace LLM apps

## Questions

### What is Phoenix?

Phoenix is an open-source AI framework, launched in 2022, made for developers and businesses. An open-source tool for tracing, evaluating and debugging LLM apps and agents.

### Is Phoenix free?

Yes. Phoenix is open source and free to use.

### Is Phoenix open source?

Yes. The source code is at https://github.com/Arize-ai/phoenix.

### Can Phoenix run locally?

Yes. Phoenix can run offline on your own machine. It can also be self-hosted on your own server.

### What can Phoenix do?

Main jobs: Evaluate and trace LLM apps. It can also do: Prompt optimization.

### What are open-source alternatives to Phoenix?

Open-source ones: Langfuse, DeepEval, promptfoo, Ragas and Pydantic AI.

## Sources

- [github.com](https://github.com/Arize-ai/phoenix) — checked 2026-09-24
- [arize.com](https://arize.com/docs/phoenix)

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Last updated 2026-09-24 · sources checked 2026-09-24 · Markdown version of https://godooo.ai/en/framework/phoenix. Every page on this site has one: add .md to its address.