Snorkel AI, a seven-year-old startup that began with data-labeling automation, has raised $350 million in a Series E led by Insight Partners and S32. The round values the company at $3.5 billion, nearly triple its previous $1.3 billion valuation from 17 months ago. Existing backers including Addition, Lightspeed, Greylock, GV, and Wells Fargo also participated.
The company has pivoted from selling labeling software to offering complete datasets and reinforcement learning environments, a model it calls data-as-a-service. Instead of relying solely on human experts, Snorkel combines its software and synthetic data generation with subject matter expertise. The company reports an annualized revenue run rate of $375 million, an eighteenfold increase over the past year.
The surge reflects broader demand for high-end training data. Other data firms like Mercor, Handshake, and Micro1 have seen similar growth, though their reported gross revenue figures are misleading because they pay out 60–70% of top-line income to domain specialists. Snorkel says its human expert payments are classified as cost of goods sold, so its revenue numbers are net of that expense.