Musk Admits Under Oath: xAI Trained Grok on OpenAI Models While Suing Them

# Musk Admits Under Oath: xAI Trained Grok on OpenAI Models While Suing Them

> **Quick answer:** Elon Musk testified in California federal court on April 30, 2026 that xAI "partly" used OpenAI model distillation to help train Grok. The admission came during Musk's own lawsuit against OpenAI — a company he is simultaneously accusing of betraying its open-source principles. In the same testimony, Musk ranked Anthropic as the number one AI company in the world, ahead of OpenAI and Google.

Elon Musk is suing OpenAI for being closed-source and profit-driven. He also, under oath, just admitted that xAI used OpenAI's models to build Grok. The Musk xAI Grok trained OpenAI models distillation testimony — delivered April 30, 2026 in a California federal courtroom — may be the most revealing moment in AI legal history. Not just for what it says about Grok's origins, but for what it says about how the entire AI industry actually works when no one is watching.

## What Musk Actually Said in Court

The moment came during cross-examination in Musk's federal lawsuit against OpenAI CEO Sam Altman, co-founder Greg Brockman, and the company itself. Musk alleges OpenAI violated its original nonprofit mission by converting to a for-profit structure.

When asked directly whether xAI had used model distillation techniques on OpenAI's models to train Grok, Musk did not deny it. Instead, he characterized the practice as "a general practice among AI companies." When the attorney pressed for a direct yes or no, Musk answered: "Partly."