Keep text in boxes

I have a unique need. I need my forms to hold whatever the user types into the text boxes of a form. I know there is an auto-save option and a “save and continue later” option but these are not working well. I want when a customer puts text in the text boxes, it remains there even when they navigate away. And when they return, the text is still there. I want it to remain there even after they submit the form. Is this possible?