Weights & Biases
wandb.ai
AI experiment tracking and model management platform for ML teams.
Quick Information
- Category:
- Coding
- Pricing:
- Freemium
- Platforms:
- Web, API
- Free Plan:
- Yes
- API Available:
- Yes
- Last Verified:
- September 2026
What Is Weights & Biases?
Weights & Biases is a machine learning platform for tracking experiments, optimizing hyperparameters, visualizing data, and managing model registries throughout the AI development lifecycle. Its Models suite handles experiment tracking, hyperparameter sweeps, tables, and reports; training tools include serverless reinforcement learning, serverless supervised fine-tuning, the ART framework, and Ruler; and Weave covers the application layer with traces, evaluations, a playground, and monitors for building agentic AI applications with guardrails. It integrates with popular frameworks including LangChain, LlamaIndex, PyTorch, TensorFlow, and XGBoost. Pricing includes a free Personal tier (unlimited experiments, unlimited tracked hours, 100 GB storage), Teams at $50/user/month, and custom Enterprise.
Its genuinely generous free Personal tier — unlimited experiments and tracked hours with 100 GB storage — provides real, substantial value for individual researchers and students rather than a token trial, and the expansion from pure experiment tracking into Weave's agentic application layer (traces, evaluations, guardrails) reflects real platform evolution to cover both traditional ML training and modern LLM/agent development workflows.
It's aimed at ML engineers, researchers, and teams building both traditional ML models and modern agentic AI applications, with the free Personal tier's genuinely unlimited experiments and 100 GB storage providing real ongoing value for individual use before Teams' $50/user/month becomes necessary for collaborative work — the broad framework integration (LangChain, PyTorch, TensorFlow, and more) means it fits into most existing ML/AI stacks without requiring workflow changes. See our Development & Code tools directory for related tools like MLflow and Comet ML.
What Can You Use Weights & Biases For?
ML experiment tracking
Tracks experiments, hyperparameter sweeps, tables, and reports throughout model development.
Agentic AI application development
Uses Weave to build agentic AI applications with traces, evaluations, and guardrails.
Model registry management
Manages model registries and artifact versioning across the AI development lifecycle.
Weights & Biases Features
- Weave — Covers the application layer for agentic AI with traces, evaluations, a playground, and monitors.
- Hyperparameter sweeps — Optimizes hyperparameters as part of the Models suite.
- Broad framework integration — Integrates with LangChain, LlamaIndex, PyTorch, TensorFlow, and XGBoost.
Who Is Weights & Biases For?
- ML engineers and researchers — Uses experiment tracking and hyperparameter optimization for traditional ML model development.
- Teams building agentic AI applications — Uses Weave’s traces, evaluations, and guardrails for LLM-based application development.
Weights & Biases Pros & Limitations
What We Like
- Genuinely generous free Personal tier with unlimited experiments and 100 GB storage, not just a token trial
- Platform evolution from pure experiment tracking into Weave’s agentic application layer covers both traditional ML and modern LLM workflows
- Broad framework integration (LangChain, PyTorch, TensorFlow, and more) fits most existing ML/AI stacks
Limitations
- Teams tier at $50/user/month can add up for larger collaborative teams
- Enterprise pricing requires custom sales engagement with no public figures
- Comprehensive feature set spanning both training and application layers may have a learning curve for teams new to the platform
Weights & Biases Pricing
| Plan | Price | Main Features |
|---|---|---|
| Personal (Free) | $0 | Unlimited experiments, unlimited tracked hours, 100 GB storage |
| Teams | $50/user/month | Collaborative experiment tracking and model management |
| Enterprise | Custom | Full enterprise feature set |
Pricing was last verified September 2026. Check the official website for the latest pricing.
AI Listing Jungle Ranking
- Global Rank:
- #416
- Overall Score:
- 51.7/100
- Monthly Users:
- 1M+
- Rank Change:
- ▲ 26
This ranking reflects AI Listing Jungle's own independent scoring methodology and is not an endorsement by Weights & Biases or its company. How Our Rankings Work
Frequently Asked Questions
Is Weights & Biases free?
Yes, the Personal tier offers unlimited experiments, unlimited tracked hours, and 100 GB storage.
What is Weave?
The application layer for building agentic AI applications with traces, evaluations, and guardrails.
How much does the Teams plan cost?
$50/user/month.
What frameworks does it integrate with?
LangChain, LlamaIndex, PyTorch, TensorFlow, and XGBoost, among others.
Our Take
Weights & Biases' genuinely generous free Personal tier — unlimited experiments and 100 GB storage — provides real, substantial value for individual researchers rather than a token trial.
The platform's evolution from pure experiment tracking into Weave's agentic application layer reflects real adaptation to cover both traditional ML training and modern LLM/agent development workflows.
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