Data development platform Snorkel AI has nearly tripled its valuation to $3.5 billion after raising $350 million in fresh funding, Reuters reported Tuesday.
The funding round was led by Insight Partners and S32, with existing investors Addition, Greylock and Wells Fargo also participating, the San Francisco-based company said. Snorkel was valued at $1.3 billion when it raised $100 million in May 2025.
Founded in 2019 by researchers from Stanford’s AI lab, Snorkel started out selling software before shifting toward finished datasets and reinforcement-learning environments for customers. CEO Alex Ratner told Reuters that demand has picked up as AI developers move beyond basic labeling and look for more complex data to train and evaluate more capable systems.
Snorkel’s platform combines human specialists with thousands of specialized AI models and agents to create and vet data. The company draws on tens of thousands of specialists across areas including coding, law, and medicine, according to the CEO.
Ratner said the new funding will go toward hiring researchers and engineers, as well as expanding Snorkel’s enterprise and government operations. The company also plans to support third-party AI model evaluations and expand into new industry verticals and data modalities.
Snorkel said it expects to reach profitability this year. The company works with frontier AI labs, hyperscalers, enterprises and the U.S. federal government, with coding data among its biggest areas of demand.
In July, Snorkel released Senior SWE-bench with researchers at Princeton University and the University of Wisconsin-Madison, an open-source benchmark that grades AI agents on long-horizon engineering tasks with under-specified instructions. Top-performing frontier models failed to complete those tasks with senior-level correctness and taste more than 75% of the time, according to the company.