To delete your Grok chat history on grok.com/app and X, go to your chat...
https://wiki-book.win/index.php/What_Should_I_Do_if_Grok_Delete_All_Doesn%E2%80%99t_Show_on_Mobile%3F
To delete your Grok chat history on grok.com/app and X, go to your chat settings and select “Delete History.” Remember, this won’t remove files or Imagine media—they need to be deleted separately