When selecting the best security keys for yourself, you'll want to factor in what degree of security you need, the authentication standard the key's based on, the security protocols it supports, the key's size, and the connectivity format.
A security key will support either USB-A, USB-C, or Lightning ports. Some security keys have Bluetooth and NFC for wireless security access.
If you want a key that'll store passwords for you and make it easier to log in to apps, websites, and accounts, pick a security key with a built-in password manager.
Look out for the security key's user interface, portability (not all keys can be attached to a keyring), and durability, among other things.