# Arize Phoenix vs Promptfoo

Arize Phoenix is free, with no paid plan attached. Promptfoo is freemium — a usable free tier with paid plans above it.

| | Arize Phoenix | Promptfoo |
|---|---|---|
| Pricing | Free | Free tier + paid plans |
| Free to start | Yes | Yes |
| Category | AI Models & Local Execution | AI Models & Local Execution |
| Type | LLM Eval & Observability | LLM Eval & Observability |
| Best for | Fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported) | Open-source CLI/library for evaluating prompts, models and RAG pipelines side by side, runs in CI |

## FAQ

### Arize Phoenix vs Promptfoo: what is the difference?

Arize Phoenix is free, with no paid plan attached and is listed for fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported). Promptfoo is freemium — a usable free tier with paid plans above it and is listed for open-source CLI/library for evaluating prompts, models and RAG pipelines side by side, runs in CI. Both sit in LLM Eval & Observability.

### Is Arize Phoenix or Promptfoo cheaper to start with?

Arize Phoenix is the cheaper starting point: it is free, with no paid plan attached, while Promptfoo is freemium — a usable free tier with paid plans above it. Pricing tiers here come from the catalog, not from a promotional page.

### Which should I choose, Arize Phoenix or Promptfoo?

Choose Arize Phoenix if you need fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported); choose Promptfoo if you need open-source CLI/library for evaluating prompts, models and RAG pipelines side by side, runs in CI. Flocci AI Tools does not rank one above the other — it shows both feature sets side by side and lets the requirement decide.

## Related

- [Arize Phoenix](https://aitools.flocci.in/tool/arize-phoenix)
- [Promptfoo](https://aitools.flocci.in/tool/promptfoo)
- [Arize Phoenix alternatives](https://aitools.flocci.in/alternatives/arize-phoenix)
- [Promptfoo alternatives](https://aitools.flocci.in/alternatives/promptfoo)
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Source: Flocci AI Tools — https://aitools.flocci.in/compare/arize-phoenix-vs-promptfoo

Facts last verified: October 2026