Snorkel AI triples valuation to $3.5 billion in Series E round
11 sourcesUpdated Sep 23, 2026
Snorkel AI on September 22, 2026 raised $350 million in Series E funding co-led by Insight Partners and S32, reaching a $3.5 billion valuation nearly triple the $1.3 billion from its May 2025 Series D. The startup shifted last year from data-labeling software to a data-as-a-service model. Source articles report an annualized revenue run-rate of $375 million, an 18-fold increase from roughly $20 million a year earlier; the wire summary states $350 million. Investors including Addition, Lightspeed, Greylock, GV, Wells Fargo, March Capital, Blumberg Capital and Allegis Capital joined. Snorkel, commercially launched in 2019 after Stanford AI Lab work led by CEO Alex Ratner, cites over 250 peer-reviewed papers with more than 25,000 citations. It books payments to human experts as cost of goods sold, unlike peers that pay 60-70% of revenue to specialists. Ratner said Snorkel was designed to be the leading lab for agentic data. The company plans to expand capacity and research with the proceeds.
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Moving into data services with all those specialists makes sense but it feels like a big pivot from their original software focus.
Snorkel hitting $350M ARR this fast shows how desperate the big AI labs are for reliable training data right now.
