Snorkel AI Funding History

Snorkel AI develops training datasets, benchmarks, evaluations and simulated environments for AI development. Its data-focused services support frontier AI labs and enterprises training and assessing models, covering both the material models learn from and the methods used to evaluate them.

Company Overview

  • Data Annotation
  • Synthetic Data

Founded 2019 · San Francisco, California, US

Official Website

Snorkel AI Funding Timeline

  1. Sep 22, 2026

    Series E

    US$350 million

    Led by Insight Partners, S32.

    Source · prnewswire.com ↗
  2. May 29, 2025

    Series D

    US$100 million · $1.3B valuation

    Snorkel announced the round alongside general availability of Snorkel Evaluate, extending its work from training data to evaluating AI systems.

    Led by Addition. Participation included NVIDIA.

    Source · businesswire.com ↗
  3. Aug 9, 2021

    Series C

    US$85 million · $1B valuation

    Led by Addition. Participation included BlackRock.

    Source · snorkel.ai ↗
  4. Apr 7, 2021

    Series B

    US$35 million

    Led by Lightspeed Venture Partners. Participation included GV, Andreessen Horowitz.

    Source · techcrunch.com ↗
  5. Jul 14, 2020

    Stealth Exit Round

    US$15 million

    Snorkel AI disclosed the financing as it emerged from stealth, commercializing work that began in a Stanford AI Lab research project.

    Led by Greylock, GV. Participation included In-Q-Tel.

    Source · businesswire.com ↗

Snorkel AI Founding Team

  • Alexander Ratner

    Co-founder and CEO of Snorkel AI; Stanford PhD who led the Snorkel research project.

    Status: activeReviewed: 2026-11-04
  • Chris Re

    Stanford University professor and individual investor in AI companies.

    Status: activeReviewed: 2026-10-14
  • Paroma Varma

    Co-founder of Snorkel AI; Head of Solutions.

    Status: activeReviewed: 2026-11-04
  • Braden Hancock

    Co-founder of Snorkel AI; Head of Technology.

    Status: activeReviewed: 2026-11-04
  • Henry Ehrenberg

    Co-founder of Snorkel AI.

    Status: activeReviewed: 2026-11-04

Snorkel AI Products

  • Snorkel AI

    Data-centric AI platform for programmatic training-data labeling and synthetic data generation to build and adapt machine learning models.

    Official Website ↗
    Details and Sources
    Status: activeReviewed: 2026-10-14

FAQ

What is weak supervision in machine learning?

Weak supervision uses imperfect labeling rules or signals to help produce training labels. Those signals can conflict and require evaluation rather than being treated as ground truth.

Why does label quality matter when a model is already large?

Evaluation and task-specific adaptation still depend on reliable examples. More model capacity does not remove ambiguity or errors in the data used to judge performance.

How does data curation differ from simply collecting more examples?

Curation selects and improves examples for a defined objective, including coverage, consistency and relevance. Raw volume alone does not establish useful training signal.

What can Snorkel AI’s financing tell us about its products?

It records investor capital for the company. Product effectiveness, customer outcomes and deployment costs need separate evidence.

Why should data-labeling workflows retain human review?

Ambiguous examples and evolving task definitions can defeat automated rules. Expert review can reveal systematic errors and clarify what the labels should mean.

How can teams assess whether curated data improves a model?

Use held-out evaluations and compare against a clear baseline. Keep test data separate from the examples used to design labeling or filtering rules.