Elon Musk Admits Under Oath That xAI Trained Grok on OpenAI Models
Elon Musk dropped a quiet bombshell in a California federal courtroom on Thursday. While testifying in his ongoing lawsuit against OpenAI, Musk was asked directly whether xAI used distillation techniques on OpenAI’s models to train Grok. His answer? “Partly.”
Distillation is the practice of systematically prompting another company’s AI model or API to extract knowledge and use it to train a competing model. It has been a hot-button issue in the AI industry, especially after U.S. labs accused Chinese AI companies of mining models like Claude to build cheaper, open-weight alternatives. But what Musk’s testimony confirms is that this is not just a China problem, xAI trained Grok on OpenAI models, making it one of the first confirmed cases of a major American lab doing the same to a domestic rival.
When pressed on the admission, Musk deflected, saying distillation was a general practice across the AI industry. That may well be true, but it doesn’t make the admission any less significant. The fact that xAI trained Grok on OpenAI models the very company Musk is currently suing adds a sharp layer of irony to an already dramatic legal battle.
Musk founded xAI in 2023, years after OpenAI had already established itself as a leader in the space. It is not entirely surprising that his team looked for ways to close that gap quickly. Distillation is not clearly illegal, but it often violates the terms of service that companies impose on users of their products and APIs.
The stakes around this practice are growing fast. OpenAI, Anthropic, and Google have reportedly joined forces through the Frontier Model Forum to share intelligence on combating distillation, with a current focus on blocking mass systematic queries that tip off the labs to copying attempts. Musk’s courtroom admission may now give those efforts a new domestic dimension to contend with.
There was another notable moment from Musk’s testimony. Asked about a boast he made last summer that xAI would soon surpass every AI company except Google, Musk quietly revised his own rankings. He placed Anthropic at the top of the current AI pecking order, followed by OpenAI and Google, with Chinese open-source models coming in behind them. He described xAI as a much smaller operation, with just a few hundred employees a far cry from the industry-dominating force he had predicted.
OpenAI did not respond to requests for comment on Musk’s admission before press time.
