Langfuse 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. 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.
Langfuse is freemium — a usable free tier with paid plans above it and is listed for fully open-source and self-hostable for free via Docker Compose/Kubernetes, not just a hosted SaaS. 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.
Neither — Langfuse 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.
Choose Langfuse if you need fully open-source and self-hostable for free via Docker Compose/Kubernetes, not just a hosted SaaS; 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.
| Langfuse | W&B Weave | |
|---|---|---|
| Pricing tier | 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 |
| Listed capabilities |
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| Tags | langfuse, llm observability, prompt management, tracing, open source, free, evaluation | weights and biases weave, agent observability, llm tracing, evaluation framework, free tier |
| Website | langfuse.com | wandb.ai |
| Full page | Langfuse details → | W&B Weave details → |
| Alternatives | Langfuse alternatives → | W&B Weave alternatives → |