How to change the html code of any site in the browser and then save it?

Question

HTML

There is such an extension for Stylish chrome, which allows you to add css code for any site and it will be saved the next time you visit the site. Thus, you can change the little things for yourself in any social network. The question is how to do the same with the html code of the page while saving it so that the next time the page is opened, the saved result opens?

Answer 1

https://addons.mozilla.org/en-US/firefox/addon/gre... for example