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

https://alpha-wiki.win/index.php/I_Deleted_Grok_on_X_but_Grok.com_Still_Shows_Chats_%E2%80%93_Is_That_Normal%3F

To delete your Grok chat history on grok.com/app and X, go to your chat settings and choose “Delete History.” Remember, this won’t remove any files or images you’ve uploaded—those need to be deleted separately