Arize Phoenix is free, with no paid plan attached. DeepEval is free, with no paid plan attached. Both are listed under LLM Eval & Observability, so this is a like-for-like comparison. Neither is ranked above the other — Flocci carries no sponsored placement.
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). DeepEval is free, with no paid plan attached and is listed for open-source LLM evaluation framework with pytest-style tests and 50+ metrics. Both sit in LLM Eval & Observability.
Neither — Arize Phoenix and DeepEval are both free, so the choice comes down to capability rather than cost. Both entries list what they uniquely do above.
Choose Arize Phoenix if you need fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported); choose DeepEval if you need open-source LLM evaluation framework with pytest-style tests and 50+ metrics. Flocci AI Tools does not rank one above the other — it shows both feature sets side by side and lets the requirement decide.
| Arize Phoenix | DeepEval | |
|---|---|---|
| Pricing tier | Free | Free |
| Free to start | Yes | Yes |
| Category | AI Models & Local Execution | AI Models & Local Execution |
| Type | LLM Eval & Observability | LLM Eval & Observability |
| Listed capabilities |
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| Tags | arize phoenix, llm observability open source, tracing, evaluation, rag debugging, free | deepeval, llm evaluation framework, pytest for llm, rag evaluation, confident ai |
| Website | phoenix.arize.com | github.com |
| Full page | Arize Phoenix details → | DeepEval details → |
| Alternatives | Arize Phoenix alternatives → | DeepEval alternatives → |