W&B Weave
Evaluation & observability · Freemium
About
Weights & Biases' toolkit for tracing, evaluating and comparing LLM application versions.
Key features
- Automatic call tracing
- Evaluation framework
- Version comparison
- Scorers and guardrails
Best for
- — Teams already on Weights & Biases
- — Evaluation leaderboards across versions
- Pricing
- Freemium
- Platforms
- Web, API
- Works with
- OpenAI, Anthropic
- Last checked
- 2026-10-29
- Status
- Listed, not yet tested
Our take
Natural fit for ML teams using W&B. Feels heavier than lighter-weight tools for small projects.
Features and pricing change often — confirm on wandb.ai before you commit.
Alternatives to W&B Weave
| Tool | Type | Pricing | Best for |
|---|---|---|---|
| W&B Weave (this) | Evaluation & observability | Freemium | Teams already on Weights & Biases |
| Langfuse | Evaluation & observability | Open source | Tracing LLM apps in production |
| LangSmith | Evaluation & observability | Freemium | LangChain and LangGraph users |
| Braintrust | Evaluation & observability | Freemium | Systematic evals before shipping |
| Arize Phoenix | Evaluation & observability | Open source | Local debugging of LLM traces |
| Helicone | Evaluation & observability | Freemium | Quick cost and usage visibility |
| promptfoo | Evaluation & observability | Open source | Prompt regression tests in CI |