# Promptfoo vs W&B Weave

Promptfoo is freemium — a usable free tier with paid plans above it. W&B Weave is freemium — a usable free tier with paid plans above it.

| | Promptfoo | W&B Weave |
|---|---|---|
| Pricing | Free tier + paid plans | 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 | Open-source CLI/library for evaluating prompts, models and RAG pipelines side by side, runs in CI | Agent-native tracing model with sessions, steps, tools and sub-agents as first-class concepts (not generic spans) |

## FAQ

### Promptfoo vs W&B Weave: what is the difference?

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. W&B Weave is freemium — a usable free tier with paid plans above it and is listed for agent-native tracing model with sessions, steps, tools and sub-agents as first-class concepts (not generic spans). Both sit in LLM Eval & Observability.

### Is Promptfoo or W&B Weave cheaper to start with?

Neither — Promptfoo and W&B Weave are both freemium, so the choice comes down to capability rather than cost. Both entries list what they uniquely do above.

### Which should I choose, Promptfoo or W&B Weave?

Choose Promptfoo if you need open-source CLI/library for evaluating prompts, models and RAG pipelines side by side, runs in CI; choose W&B Weave if you need agent-native tracing model with sessions, steps, tools and sub-agents as first-class concepts (not generic spans). Flocci AI Tools does not rank one above the other — it shows both feature sets side by side and lets the requirement decide.

## Related

- [Promptfoo](https://aitools.flocci.in/tool/promptfoo)
- [W&B Weave](https://aitools.flocci.in/tool/w-b-weave)
- [Promptfoo alternatives](https://aitools.flocci.in/alternatives/promptfoo)
- [W&B Weave alternatives](https://aitools.flocci.in/alternatives/w-b-weave)
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Source: Flocci AI Tools — https://aitools.flocci.in/compare/promptfoo-vs-w-b-weave

Facts last verified: October 2026