Most apps need to know the identity of a user. Knowing a user's identity allows an app to securely save user data in the cloud and provide the same personalized experience across all of the user's devices.
Firebase Authentication provides backend services, easy-to-use SDKs, and ready-made UI libraries to authenticate users to your app. It supports authentication using passwords, popular federated identity providers like Google, Facebook and Twitter, and more.
Firebase Authentication integrates tightly with other Firebase services, and it leverages industry standards like OAuth 2.0 and OpenID Connect, so it can be easily integrated with your custom backend.
Easily add a complete sign-in system to your app. FirebaseUI provides a drop-in auth solution that handles the UI flows for signing in users with email addresses and passwords, Google Sign-In, and Facebook Login.
The FirebaseUI Auth component implements best practices for authentication on mobile devices and websites, which can maximize sign-in and sign-up conversion for your app. It also handles edge cases like account recovery and account linking that can be security sensitive and error-prone to handle correctly.
FirebaseUI can be easily customized to fit in with the rest of your app's visual style, and it is open source, so you aren't constrained in realizing the user experience you want.
Email and password based authentication
Authenticate users with their email addresses and passwords.
The Firebase Authentication SDK provides methods to create and manage users that use their email addresses and passwords to sign in. Firebase Authentication also handles sending password reset emails.
Identity provider integration
Authenticate users by integrating with federated identity providers. The Firebase Authentication SDK provides methods that allow users to sign in with their Google, Facebook, Twitter, and GitHub accounts.
Use Firebase features that require authentication without requiring users to sign in first by creating temporary anonymous accounts. If the user later chooses to sign up, you can upgrade the anonymous account to a regular account, so the user can continue where they left off.