It doesn't look like it follows links though, so it's much more of an alternative to "Save As -> mhtml" than to HTTrack.

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

Cool! Thanks for sharing! I've been on the lookout for replacements for archiving recipies on cooking sites and this tool works great.

There is also SingleFile as a browser extension: https://github.com/gildas-lormeau/SingleFile

Note that SingleFile can also crawl websites when run from the CLI (see the --crawl-* options)

I also recommend this wholeheartedly.