Their product didn't work Their product didn't work. Customer service offered a partial refund (excluding shipping costs). That's unheard of. When a product is returned, all payments are refunded and some will even send the client a free shipping label. When a product is faulty, that's goes without saying.

Stress-free 2FA I've got two Yubico Security Key NFC keys and the build quality is excellent. They've been pain-free to set up on all my devices and with all of the online accounts that supports them. It might be worthwhile checking which services support specific Yubico keys before buying them so you won't be disappointed, since it varies depending on the model you buy. These keys have been great for my personal use and the companion app, YubiKey Manager, is nice and simple to use.

Solid security keys I've owned a variety of YubiKeys since 2014, and I've always been very happy with them, I've only had to replace them either because I lost them or because I wanted some newer features, like USB-C or NFC. They seem to be the gold standard for security keys for a reason.

series 5 nfc buggy bought 2 series 5 nfc totally buggy to a point where yubikey-manager couldn’t read the seriol# of both keys anymore and AOL rejected both keys in that condition. support totally ignored my issues and closed my tickets before solving them How does anyone trust a company or a piece of hardware that buggy??

Using Yubikey introduces the risk of the rightful owner of account is prevented access. It is a problem that Yubikeys cannot be duplicated for backup. They are so secure that even the owner of an account can be locked out, lol. That's not good. In case of lost key or hardware malfunction there is no way to access your account. Unfortunatly two different keys often cannot be registered for the same access. Using Yubikey introduces the risk of the rightful owner of account is prevented access.