Snorkel AI Raises $350M, Tripling Its Valuation to $3.5B on AI Training Data Demand

Snorkel AI raised $350 million in a Series E round on September 22, 2026, tripling its valuation to $3.5 billion amid soaring demand for AI training data and expert-built datasets.

Who Invested

Insight Partners and S32 led the round, with existing investors Addition, Greylock and Wells Fargo also participating. The new valuation is nearly three times the $1.3 billion Snorkel reached when it raised a $100 million Series D in May 2025.

Revenue Up From $20M to $350M

Snorkel's annualized revenue run-rate has crossed $350 million, up from roughly $20 million a year earlier — one of the steepest growth curves in enterprise AI.

From Labeling Software to Data-as-a-Service

Founded in 2019 as a spin-out from the Stanford AI lab, Snorkel originally sold software to help companies label and manage training data. In September 2025 it launched a data-as-a-service business, supplying finished datasets and reinforcement-learning environments directly to customers — the business behind its recent growth.

Data Is the Differentiator

As model access becomes cheaper and more interchangeable, high-quality domain data is where much of the value is moving. For enterprises, the clean, well-labeled data they already own is often a bigger AI advantage than the choice of model.