I use SingleFile [0] in the browser:
"SingleFile is a Web Extension (and a CLI tool) compatible with Chrome, Firefox (Desktop and Mobile), Microsoft Edge, Vivaldi, Brave, Waterfox, Yandex browser, and Opera. It helps you to save a complete web page into a single HTML file."
I really like and often use the option to highlight text and add notes to a web page before saving it locally. After saving the file you can easily do a full-text search because, e.g., both macOS Finder and Windows Explorer index HTML files by default.