Arize Phoenix is free, with no paid plan attached. OpenLLMetry (Traceloop) 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). OpenLLMetry (Traceloop) is free, with no paid plan attached and is listed for openTelemetry-based instrumentation for LLM calls, vector DBs and frameworks. Both sit in LLM Eval & Observability.
Neither — Arize Phoenix and OpenLLMetry (Traceloop) 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 OpenLLMetry (Traceloop) if you need openTelemetry-based instrumentation for LLM calls, vector DBs and frameworks. 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 | OpenLLMetry (Traceloop) | |
|---|---|---|
| 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 |
|
|
| Tags | arize phoenix, llm observability open source, tracing, evaluation, rag debugging, free | openllmetry, opentelemetry llm, traceloop, llm observability open source, otel ai tracing |
| Website | phoenix.arize.com | github.com |
| Full page | Arize Phoenix details → | OpenLLMetry (Traceloop) details → |
| Alternatives | Arize Phoenix alternatives → | OpenLLMetry (Traceloop) alternatives → |