Arize Phoenix vs DeepEval
A side-by-side comparison of two self-hosted self-hosted ai options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Arize Phoenix | DeepEval |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Health score | 93 · Excellent | 95 · Excellent |
| Category | Self-Hosted AI | Self-Hosted AI |
| License | Elastic-2.0 | Apache-2.0 |
| Language | Python | Python |
| Setup difficulty | Medium | Medium |
| Min. RAM | 1,024 MB | 1,024 MB |
| Deployment | docker, source | source |
| GitHub stars | ★ 11,594 | ★ 18,419 |
| First released | 2023 | 2023 |
| Replaces | LangSmith, Helicone | LangSmith, Braintrust |
What are Arize Phoenix and DeepEval?
Arize Phoenix
Phoenix by Arize is an open-source observability platform for experimentation, evaluation and troubleshooting of LLM and ML applications. It runs as a self-hosted server collecting OpenTelemetry traces from AI apps.
- LLM tracing and spans
- Built-in evaluators
- OpenTelemetry-based
- Self-hostable
DeepEval
DeepEval is an open-source evaluation framework that brings unit-testing-style assertions to large language model outputs. It includes metrics for hallucination, relevancy, and bias and integrates with pytest for local CI.
- Pytest-style LLM tests
- 14+ built-in metrics
- Synthetic dataset generation
- CI/CD integration
Arize Phoenix vs DeepEval: key differences
Both projects are written in Python. Licensing differs — Elastic-2.0 for Arize Phoenix versus Apache-2.0 for DeepEval. Arize Phoenix lists first-class Docker deployment; DeepEval does not.
Why pick each one
Choose Arize Phoenix if…
- Released under the Elastic-2.0 license
- First-class Docker support for quick deployment
- Mature project with 11.6k GitHub stars
- Written in Python
Choose DeepEval if…
- Pytest-style LLM tests
- Rich metric library
- Runs in CI
Watch out for
- LLM judge token costs
- Cloud platform upsell
Frequently asked questions
Is Arize Phoenix or DeepEval better?
Neither is universally better. DeepEval has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Arize Phoenix and DeepEval free and open-source?
Yes. Arize Phoenix is licensed under Elastic-2.0 and DeepEval under Apache-2.0. Both can be self-hosted at no software cost.
Can I run Arize Phoenix and DeepEval with Docker?
Arize Phoenix: yes. DeepEval: check the project docs for container support.