Get Started with Firebase Authentication on Websites

You can use Firebase Authentication to allow users to sign in to your app using one or more sign-in methods, including email address and password sign-in, and federated identity providers such as Google Sign-in and Facebook Login. This tutorial gets you started with Firebase Authentication by showing you how to add email address and password sign-in to your app.

Connect your app to Firebase

Install the Firebase SDK. Be sure to paste the configuration code into your web page as described.

Sign up new users

Create a form that allows new users to register with your app using their email address and a password. When a user completes the form, validate the email address and password provided by the user, then pass them to the createUserWithEmailAndPassword method:

firebase.auth().createUserWithEmailAndPassword(email, password).catch(function(error) {
  // Handle Errors here.
  var errorCode = error.code;
  var errorMessage = error.message;
  // ...
});email-password.html

Sign in existing users

Create a form that allows existing users to sign in using their email address and password. When a user completes the form, call the signInWithEmailAndPassword method:

firebase.auth().signInWithEmailAndPassword(email, password).catch(function(error) {
  // Handle Errors here.
  var errorCode = error.code;
  var errorMessage = error.message;
  // ...
});email-password.html

Set an authentication state observer and get user data

For each of your app's pages that need information about the signed-in user, attach an observer to the global authentication object. This observer gets called whenever the user's sign-in state changes.

Attach the observer using the onAuthStateChanged method. When a user successfully signs in, you can get information about the user in the observer.

firebase.auth().onAuthStateChanged(function(user) {
  if (user) {
    // User is signed in.
    var displayName = user.displayName;
    var email = user.email;
    var emailVerified = user.emailVerified;
    var photoURL = user.photoURL;
    var isAnonymous = user.isAnonymous;
    var uid = user.uid;
    var providerData = user.providerData;
    // ...
  } else {
    // User is signed out.
    // ...
  }
});email-password.html

Next steps

Learn how to add support for other identity providers and anonymous guest accounts: