To delete your Grok chat history on grok.com/app and X, go to your chat...

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, go to your chat settings and choose the delete option. Remember, this removes only your text chats. If you saved files or Imagine media, you'll need to delete those separately