
You can even use one to log into your Mac. Other YubiKeys are supported by dozens of online services, including Dashlane, Dropbox, Facebook, Instagram, KeePass, Keeper, Microsoft, Nintendo, Okta, Reddit, Twitter and WordPress. Yubico says the YubiKey 5ci is already supported by the LastPass and 1Password iOS apps, and many more online services are sure to follow, although each will have to implement its own support for the moment.

We had no trouble registering the 5ci to our Google account using the USB-C port on a Windows PC, but when we tried to log into our Gmail account on iOS, the Google Smart Lock app on iOS, required for Google 2FA on iOS, didn't recognize the security key. Unfortunately, we found that support for the 5ci on iOS was still pretty limited. We got a YubiKey 5ci in advance and borrowed an iPhone to see how well the two devices play together. Can a free iPhone VPN match up to a paid iPhone VPN?.
