This free tool converts the bookmarks HTML file exported from browsers (Chrome, Firefox and others) to Markdown (.md) format.
It runs from a plain HTML file: no installation, no extensions, no command line, no permissions. Use the same browser you used to create the backup.
Online version
If you don't want to download any file, there is an online version here
Developers
If you would like to implement the conversion engine into another program or code, you can find the commented JavaScript code inside the index.hml source file. Please note that it requires a DOM object holding the contents of the HTML file.
License
MIT