There is also a similar program called HyperFiler[0]* that bundles web pages into single HTML files with a few more options such as a headless chromium transport option, built in minifiers, page sanitizers, and an option to grayscale the output pages, among other options. It's TypeScript based and has an programmatic API to customize the bundling process as well.

[0] https://github.com/chowderman/hyperfiler

* disclaimer: I created HyperFiler