Arize Phoenix vs promptfoo
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 | promptfoo |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Health score | 93 · Excellent | 97 · Excellent |
| Category | Self-Hosted AI | Self-Hosted AI |
| License | Elastic-2.0 | MIT |
| Language | Python | TypeScript |
| Setup difficulty | Medium | Easy |
| Min. RAM | 1,024 MB | 1,024 MB |
| Deployment | docker, source | bare-metal, binary, source |
| GitHub stars | ★ 11,583 | ★ 25,379 |
| First released | 2023 | 2023 |
| Replaces | LangSmith, Helicone | LangSmith |
What are Arize Phoenix and promptfoo?
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
promptfoo
promptfoo is a developer-friendly tool for testing and evaluating prompts, models, and RAG systems. It supports automated evaluations, comparisons, and security red-teaming with a local web viewer.
- Automated prompt evals
- Model comparison matrix
- Red-teaming and security tests
- Local web viewer
Arize Phoenix vs promptfoo: key differences
Arize Phoenix is written in Python, while promptfoo is built with TypeScript. Licensing differs — Elastic-2.0 for Arize Phoenix versus MIT for promptfoo. Promptfoo has the considerably larger community, at 25,379 GitHub stars versus 11,583. Arize Phoenix lists first-class Docker deployment; promptfoo 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 promptfoo if…
- Simple YAML configs
- Red-teaming built in
- Runs fully locally
Watch out for
- CLI-centric workflow
- Node.js required
Frequently asked questions
Is Arize Phoenix or promptfoo better?
promptfoo is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider Arize Phoenix if its specific feature set fits your needs better.
Are Arize Phoenix and promptfoo free and open-source?
Yes. Arize Phoenix is licensed under Elastic-2.0 and promptfoo under MIT. Both can be self-hosted at no software cost.
Can I run Arize Phoenix and promptfoo with Docker?
Arize Phoenix: yes. promptfoo: check the project docs for container support.