With Apple making a big push toward passwordless authentication, I thought it would be time to figure out how to get it working on a website using the technologies that I like. I've tested it with TouchID on my Mac, FaceID on my iPhone, and Windows Hello on my PC. I'd love for you to try it out. You can register as a user with a username and email address, then you go immediately to setting up passwordless authentication with your device. Next time you come back (or if you just click "Logout" then "Login"), it will remember you, and you can log in using your device again. You can also get a magic login link as a fallback, or to register on a different device.
It was quite difficult to figure out at first, but, within about a week, I had a working demo using Python's Flask framework and a few of my other favorite technologies. I wrote a series of blog posts about building it. They're fairly technical and really only useful if you're already well-versed in Python and Flask and some Javascript. And if you're really a nerd like me, you can check out the source code.