Snorkel AI Secures $100 Million Funding to Develop Advanced AI Evaluators

Introduction to Snorkel AI

Snorkel AI CEO Alex Ratner said his company is placing more emphasis on helping subject matter experts build datasets and models for evaluating AI systems. Alex Ratner, CEO of Snorkel AI, remembers a time when data labeling —the grueling task of adding context to swathes of raw data and grading an AI model’s response— was considered “janitorial” work among AI researchers. But that quickly changed when ChatGPT stunned the world in 2022 and breathed new life (and billions of dollars) into a string of startups rushing to supply human-labeled data to the likes of OpenAI and Anthropic to train capable models.

Shift in Data Labeling

Now, the crowded field of data labeling appears to be undergoing another shift. Fewer companies are training large language models from scratch, leaving that task instead to the tech giants. Instead, they are fine-tuning models and building applications in areas like software development, healthcare, and finance, creating demand for specialized data. AI chatbots no longer just write essays and haikus; they’re being tasked with high-stakes jobs like helping physicians make diagnoses or screening loan applications, and they’re making more mistakes. Assessing a model’s performance has become crucial for businesses to trust and ultimately adopt AI, Ratner said. “Evaluation has become the new entry point,” he told Forbes.

New Direction for Snorkel AI

That urgency for measuring AI’s abilities across very specific use cases has sparked a new direction for Snorkel AI, which is shifting gears to help enterprises create evaluation systems and datasets to test their AI models and adjust them accordingly. Data scientists and subject matter experts within an enterprise use Snorkel’s software to curate and generate thousands of prompt and response pairs as examples of what a correct answer looks like to a query. The AI model is then evaluated according to that dataset, and trained on it to improve overall quality.

Funding and Growth

The company has now raised $100 million in a Series D funding round led by New York-based VC firm Addition at a $1.3 billion valuation— a 30% increase from its $1 billion valuation in 2021. The relatively small change in valuation could be a sign that the company hasn’t grown as investors expected, but Ratner said it’s a result of a “healthy correction in the broader market.” Snorkel AI declined to disclose revenue.

Success Stories

Customer support experts at a large telecommunication company have used Snorkel AI to evaluate and fine-tune its chatbot to answer billing-related questions and schedule appointments, Ratner told Forbes. Loan officers at one of the top three U.S. banks have used Snorkel to train an AI system that mined databases to answer questions about large institutional customers, improving its accuracy from 25% to 93%, Ratner said. For nascent AI startup Rox that didn’t have the manpower or time to evaluate its AI system for salespeople, Snorkel helped improve the accuracy by between 10% to 12%, Rox cofounder Sriram Sridharan told Forbes.

Competition and Challenges

It’s a new focus for the once-buzzy company, which spun out of the Stanford Artificial Intelligence Lab in 2019 with a product that helped experts classify thousands of images and text. But since the launch of ChatGPT in 2022, the startup has been largely overshadowed by bigger rivals as more companies flooded the data labeling space. Scale AI, which also offers data labeling and evaluation services, is reportedly in talks to finalize a share sale at a $25 billion valuation, up from its $13.8 billion valuation a year ago. Other competitors include Turing, which doubled its valuation to $2.2 billion from 2021, and Invisible Technologies, which booked $134 million in 2024 revenue without raising much from VCs at all.

Differentiation and Future Plans

Snorkel has faced macro challenges too: As AI models like those powering ChatGPT got better, they could label data on a massive scale for free, shrinking the size of the market further. Ratner acknowledged that Snorkel saw a brief period of slow growth right after OpenAI launched ChatGPT and said enterprises had paused pi