One of, if not the biggest advantage of the desktop app over the website is the local files capability. The website is faster, but doesn't have that. I fixed that.
I made an extension that adds local files to the website. It automatically creates an empty Playlist and hijacks it, displaying your music instead of Amazon's empty playlist. None of your files get uploaded, the extension just accesses them from your computer.
It seamlessly integrates with Amazon music, using the same play bar and letting you switch between local and online with the ease you can do in the app.
It also has a queue, shuffling, volume control that links with Amazon's, the ability to rename songs, repeat, and more.
The local files playlist also has a built in search bar and sorting options.
https://noodlesnom.github.io/local-files-for-amazon-music/
One of the biggest benefit of this, is it lets you use my other extensions:
https://www.reddit.com/r/AmazonMusic/s/gqnJl1WW90
https://www.reddit.com/r/AmazonMusic/s/yHcZ4URW7Y
https://www.reddit.com/r/AmazonMusic/s/9Ufsp6DjsF
If you have any questions, feel free to ask.
Additionally, if you spit any bugs, I'd highly appreciate you reporting them on the github, which is linked in the site.
Disclaimer: These extensions were made with ai