Snorkel AI announced on September 22, 2026, that it has raised $350 million in Series E funding, tripling its valuation to $3.5 billion. The funding round, co-led by Insight Partners and Section 32, reflects a significant increase in demand for advanced AI training data.
The company's valuation has surged from $1.3 billion following its $100 million Series D round in May 2025. Snorkel AI's CEO, Alex Ratner, stated that the company's data-as-a-service offering, launched less than a year prior to the announcement, has seen an eighteenfold increase in growth and achieved an annualized revenue run rate of $375 million. This growth is attributed to the increasing need for complex datasets and simulated environments required by frontier AI laboratories.
The latest funding round saw participation from existing investors including Addition, Greylock, and Wells Fargo, alongside new investors such as Third Point, March, Blumberg, Allegis, Standard VC, and Frontline. Snorkel AI, founded in 2019 as a spin-out from Stanford's AI lab, initially focused on software but has since shifted its business model. It now provides finished datasets and reinforcement-learning environments directly to clients. The company's platform pairs human experts with specialized AI agents to create and validate data, a model designed to meet the growing demand for sophisticated training data as AI systems become more capable.
Ratner explained that AI developers are moving beyond basic data labeling tasks and require more complex, higher-stakes data for training and evaluating advanced AI systems. Snorkel AI's approach involves experts defining design scenarios, tasks, and grading rubrics, while AI automates much of the quality assurance process. The company collaborates with AI labs to design methods for acquiring high-quality datasets, leveraging a network of tens of thousands of specialists across various fields like coding, law, and medicine. Snorkel AI generates revenue by selling the data products created through this process, rather than charging for human labor, which allows for more competitive expert compensation while maintaining company margins.
The company plans to use the new capital to hire researchers and engineers, expand its enterprise and government operations, and support third-party AI model evaluations. Snorkel AI also intends to enter new industry verticals and explore additional data modalities. Additionally, Snorkel AI will expand its Open Benchmarks Grants program with a $3 million commitment to fund independent AI benchmarks, supporting open and diverse evaluation of AI capabilities.