Flutter › Firebase Authentication in Flutter
What is Firebase Authentication, and what different sign in methods does it support out of the box for a Flutter app?
BeginnerAnswer
Firebase Authentication is a fully managed authentication service that handles the significant complexity of securely signing users up, logging them in, and managing their entire account session for you, supporting a wide range of built in sign in methods out of the box, including traditional email and password login, popular social sign in options such as Google, Apple, and Facebook, and phone number based verification using a one time text message code, letting a Flutter app add a genuinely robust, secure authentication system without needing to build and maintain an entirely custom authentication backend from scratch.
final credential = await FirebaseAuth.instance.signInWithEmailAndPassword(
email: email,
password: password,
);Real-world example A new startup adds email and password login along with Google sign in to their Flutter app using Firebase Authentication, launching a fully functional and genuinely secure login system within just a single day, rather than needing to build an entire custom authentication backend themselves.