Snorkel AI Triples Valuation to $3.5B as Training Data Demand Explodes

Snorkel AI has raised a $350 million Series E at a $3.5 billion valuation, nearly triple the $1.3 billion it commanded seventeen months ago. Insight Partners and S32 led the round, with existing investors Addition, Lightspeed, Greylock, GV, and Wells Fargo participating.

The seven-year-old company, which grew out of four years of Stanford AI lab research by co-founder and CEO Alex Ratner, originally sold software for automating data labeling. Last year it pivoted to delivering finished datasets under a data-as-a-service model, combining its own software and synthetic generation with subject matter experts rather than operating a pure human marketplace.

The company says its annualized revenue run rate now stands at $375 million, an eighteenfold increase over the past twelve months, fueled by AI labs' escalating appetite for high-end training data and reinforcement learning environments.

Snorkel's growth mirrors a broader surge among AI data companies. Mercor's gross annualized revenue has reached $2 billion, Handshake crossed $1 billion earlier this year, and Micro1 scaled to $500 million. Those firms pay out roughly 60 to 70 percent of their top-line income to the domain specialists doing the work, making their net revenue considerably lower than the headline figures. Snorkel's accounting differs: because it sells environments and datasets rather than human labor, expert payments sit in its cost of goods sold.

The round is another signal that the picks-and-shovels layer of the AI boom, the data that trains and evaluates frontier models, has become one of the industry's fastest-growing markets in its own right.