To delete your Grok chat history on grok.com/app and X, open your chat settings...

https://stateofseo.com/how-do-i-handle-a-stubborn-grok-file-that-wont-delete/

To delete your Grok chat history on grok.com/app and X, open your chat settings and select "Clear History." Remember, this doesn’t remove files or Imagine media—they must be deleted separately