Login via QR Code is Slick

Discord, TikTok, and Steam all support scanning QR codes to login:

It’s a pretty quick way to login, the only caveat is you need to have their mobile app installed.

And because of this, services / sites / projects without mobile apps can’t support this login method.

Confirming

There’s also some security risk where an attacker gets a user to scan a QR code the attacker generated on their own computer, allowing them access to the user’s account.

Steam’s confirm page does the best job at attempting to prevent this attack:

Discord has a general warning:

While TikTok is pretty sparse:

Conclusion

This login method is nice, but requires users to have the service’s app downloaded.