Evaluation · Updated 2026-10-25
W&B Weave — what it is actually for
W&B Weave provides tracing, evaluation, and monitoring for LLM applications and integrates with Weights & Biases experiment tracking. It is available on the W&B Free, Pro, and Enterprise plans.
Short answer: use W&B Weave when you need llm tracing and evaluation. It is a free tier + subscription service from Weights & Biases (CoreWeave); the official pricing source is linked below.
- Vendor
- Weights & Biases (CoreWeave)
- Category
- Evaluation
- Pricing model
- Free tier + subscription
- Free option
- Yes. The W&B Free plan includes AI application evaluations, tracing, and scorers.
What W&B Weave is used for
- LLM tracing and evaluation
- Comparing model and prompt versions
- Team dashboards alongside experiment tracking
Source: official product page and official documentation.
Who W&B Weave is for
- Teams already using Weights & Biases
- ML teams that want evals and experiment tracking together
- Organizations that need enterprise controls
Source: official documentation.
Who it is not for
- Teams that want lightweight standalone tracing
- Buyers who need a free self-hosted edition
Source: documented plans, limits, and deployment model on the official product page.
Pricing
- Free plan for personal development, including AI application evaluations, tracing, and scorers.Source: wandb.ai
- Pro starts at US$60 per month with a 30-day free trial and adds unlimited teams, access controls, and automations.Source: wandb.ai
- Enterprise pricing is custom. Academic research has a separate free program.Source: wandb.ai
W&B was acquired by CoreWeave; the pricing page now brands the platform as CoreWeave Forge.
Full pricing page: https://wandb.ai/site/pricing
Alternatives to W&B Weave
- LangSmith — Tracing, evaluation, and observability for LLM and agent applications.
- Braintrust — Evaluation, logging, and prompt playground for AI products.
- Arize Phoenix — Open-source LLM tracing and evaluation, with a managed cloud.
Official sources
W&B Weave FAQ
Is W&B Weave free?
Yes. The W&B Free plan includes AI application tracing, evaluations, and scorers.
How much does W&B Pro cost?
Pro starts at US$60 per month and includes a 30-day free trial.
Does Weave replace experiment tracking?
No. Weave is the LLM application tracing and evaluation layer inside the broader Weights & Biases platform.