A passkey is a more secure alternative to passwords that can be used to sign in to supported apps and websites on Apple devices. Passkeys are unique for every account and are generated by the device, making them less vulnerable to phishing attacks. They work alongside passwords and are stored in iCloud Keychain, where they are encrypted and not visible to anyone, including Apple. Passkeys can be created and saved on an iPhone, and they work on all devices that are signed in to the same Apple ID. To use passkeys, iOS 16, iPadOS 16, macOS 13, or tvOS 16 (or later) is required, and iCloud Keychain and two-factor authentication must also be turned on.

Passkeys are built on the WebAuthentication (or "WebAuthn") standard, which uses public key cryptography. During account registration, the operating system creates a unique cryptographic key pair to associate with an account for the app or website. These keys are generated by the device, securely and uniquely, for every account, making passkeys very strong, easy to use credentials that are highly phishing-resistant. Passkeys sync across a users devices using iCloud Keychain.

Passkeys can be created for new accounts or to replace the password for an existing account. They can be used to sign in to an account on an iPhone, Mac, or Magic Keyboard using Touch ID or Face ID to identify the user. Passkeys can also be saved to a hardware security key.

Passkeys are designed to be more secure than passwords, as they are resistant to phishing, always strong, and there are no shared secrets. They simplify account registration for apps and websites, are easy to use, and work across all of your Apple devices, and even non-Apple devices within physical proximity.