Weights and Biases
Weights & Biases builds tools for AI developers. Its platform helps machine-learning and generative-AI teams track, evaluate, monitor, reproduce, and improve models and AI applications.
At a Glance
- AI research labs and foundation-model builders
- Enterprise machine-learning and data-science teams
- Generative-AI application and agent developers
- Automotive and autonomous-driving companies
- +2 more
AI Tools by Weights and Biases
(2)
Weave
LLM App Tracing and Evaluation
Weights & Biases
MLOps Experiment Tracking Platform
Discussions
No discussions yet
Be the first to start a discussion about Weights and Biases
Latest News
CoreWeave and Weights & Biases announced Mission Control integration, W&B Inference, and W&B Weave Online Evaluations.
W&B Weave became available in the new AWS Marketplace AI Agents and Tools category.
CoreWeave completed its acquisition of Weights & Biases.
Weights & Biases and NTT DATA announced a collaboration to accelerate custom LLM development and enterprise agentic AI.
Products & Services
System of record for ML experimentation: logs runs, metrics, hyperparameters, code, datasets, and artifacts so teams can compare experiments and reproduce results.
Model development and management capabilities, including training/fine-tuning workflows, model and dataset versioning, registry and lineage, and integration with infrastructure diagnostics.
Open-source Python and TypeScript toolkit and hosted platform for tracing agents and LLM calls, evaluating applications with LLM judges and custom scorers, collecting feedback, and monitoring production behavior.
Production-time evaluation and monitoring that provides real-time insight into AI-agent performance on any cloud platform.
Market Position
W&B positions itself as a developer-first, end-to-end AI developer platform spanning model training, experiment tracking, data/model governance, and LLM application development. Its competitive set includes MLflow, Comet, Neptune.ai, ClearML, Databricks/Mosaic AI, Arize, LangSmith, Humanloop, and Galileo; W&B differentiates by combining mature MLOps experiment management with Weave's LLMOps tracing/evaluation and, after joining CoreWeave, tighter cloud/inference integration while preserving multi-cloud and on-prem deployment flexibility.
Leadership
Founders
Lukas Biewald
Co-founder of Weights & Biases and previously co-founder of CrowdFlower, later renamed Figure Eight. He worked with machine-learning researchers at Stanford and OpenAI and served as W&B's CEO/co-founder and later General Manager.
Chris Van Pelt
Co-founder of Weights & Biases and co-founder of CrowdFlower/Figure Eight; a software and web-application engineer who previously built the startup with Lukas Biewald.
Shawn Lewis
Co-founder of Weights & Biases; recruited by Biewald and Van Pelt as a longtime friend with prior founder experience and became a distinguished engineer/co-founder (previously CTO).
Executive Team
Lukas Biewald
General Manager and Co-founder
Previously co-founded CrowdFlower/Figure Eight; machine-learning entrepreneur and former W&B CEO.
Chris Van Pelt
Distinguished Engineer and Co-founder
Previously co-founded CrowdFlower/Figure Eight and has a software/web-application engineering background.
Board of Directors
Founding Story
The founders started W&B in San Francisco after seeing that machine-learning practitioners had inadequate tools: experiment tracking was manual and reproducing models was difficult. During Lukas Biewald's work with researchers at OpenAI, the team developed an experiment-tracking tool to help build models, with the initial vision of bringing software-quality tooling and reproducibility to ML practitioners.
Business Model
Revenue Model
Freemium SaaS/platform model: free individual and academic use, paid Pro subscriptions, usage-based storage and Weave data ingestion, model inference charges, and custom Enterprise contracts with private hosting, security, compliance, support, and connectivity options.
Pricing Tiers
Personal AI application/model development; includes evaluations, tracing, scorers, experiment tracking, asset registry/lineage, community support, up to 5 model seats, 5 GB/month storage, and 1 GB/month Weave ingestion.
Adds unlimited teams, team access controls, service accounts, priority email/chat support, CI/CD automations, Slack/email alerts, up to 10 model seats, and higher usage allowances.
Adds security/compliance options including HIPAA, private connectivity, customer-managed encryption keys, SSO, automated provisioning, custom roles, audit logs, and enterprise support.
Target Markets
- AI research labs and foundation-model builders
- Enterprise machine-learning and data-science teams
- Generative-AI application and agent developers
- Automotive and autonomous-driving companies
- Technology, financial-services, healthcare, pharmaceutical, retail, and industrial companies
- Academic researchers and early-stage teams
- Training and fine-tuning machine-learning and foundation models
- Reproducible research and experiment management
- Dataset and model governance across enterprise ML teams
- Building, tracing, evaluating, and monitoring LLM applications and AI agents
- RAG and generative-AI application quality measurement
- Production deployment diagnostics and AI-infrastructure/model iteration
- OpenAI
- NVIDIA
- Cohere
- Meta