.mhtml (or .mhtm) is that format. It's an archive containing an HTML file along with all the resources it references (JavaScript, CSS, and images). These browsers support it: Internet Explorer, Edge, Opera, Chrome, Yandex, and Vivaldi. Create one by saving the web page and choosing the .mhtml format. Safari supports another format called webarchive.

https://en.wikipedia.org/wiki/MHTML