What It Does
Weights and Biases (W&B) is an ML development platform that provides experiment tracking, model evaluation, dataset versioning, and hyperparameter optimization. It helps ML teams track, compare, and reproduce model training runs at scale.
Key Features
- Experiment tracking — log metrics, hyperparameters, and artifacts from training runs
- Sweeps — automated hyperparameter optimization
- Artifacts — version control for datasets and models
- Tables — interactive data visualization and comparison
- Reports — collaborative documents combining code, data, and analysis
- Model registry — manage model lifecycle and deployment
- Weave — LLM application evaluation and tracing
- Launch — job scheduling and compute management
Pricing Breakdown
| Tier | Price | Features |
|---|---|---|
| Free | $0 | 100GB storage, unlimited experiments |
| Team | $50/user/mo | Collaboration, support |
| Enterprise | Custom | SSO, audit, dedicated |
Who It’s For
ML engineers, research teams, and AI companies training and fine-tuning models. Essential for teams running many experiments who need to track what works and reproduce results.
Competitive Position
W&B is the dominant experiment tracking platform, used by most major AI labs (OpenAI, Anthropic, Google DeepMind). Its community adoption creates strong network effects. The Weave product extends into LLM evaluation, competing with LangSmith. Competes with MLflow (open source, less polished) and Neptune.ai. Strong moat through integrations with every major ML framework.