Microsoft Authenticator is a mobile app that provides easy and secure sign-ins for all your online accounts using multi-factor authentication, passwordless, or password autofill. With multi-factor authentication, you'll enter your password and then be asked for an additional way to prove it's really you, such as approving a notification sent to the app or entering a one-time password generated by the app. Passwordless sign-in allows you to use your phone, not your password, to log into your Microsoft account, using your fingerprint, face ID, or PIN for a second layer of security. Autofill passwords are also available, with multi-factor authentication protecting your passwords in the app.<br/><br/>To get started with multi-factor authentication, simply add your accounts to the app, including non-Microsoft accounts like Facebook, Amazon, Dropbox, Google, LinkedIn, GitHub, and more. For passwordless sign-in, enter your username and approve the notification sent to your phone, using your fingerprint, face ID, or PIN for a second layer of security. Autofill passwords are available by signing in on the Passwords tab inside the Authenticator app with your personal Microsoft account to start syncing passwords, including those saved in Microsoft Edge.<br/><br/>For work or school accounts, your organization may ask you to install the Microsoft Authenticator when accessing certain files, emails, or apps. You will need to register your device to your organization through the app and add your work or school account. Microsoft Authenticator also supports cert-based authentication by issuing a certificate on your device, letting your organization know that the sign-in request is coming from a trusted device and helping you seamlessly and securely access additional Microsoft apps and services without needing to log into each. Single sign-on is also available, allowing you to prove your identity once and not need to log in again to other Microsoft apps on your device.