Easily add sign-in to your Web app with FirebaseUI

FirebaseUI is a library built on top of the Firebase Authentication SDK that provides drop-in UI flows for use in your app. FirebaseUI provides the following benefits:

  • Multiple Providers - sign-in flows for email/password, email link, phone authentication, Google, Facebook, Twitter and GitHub sign-in.
  • Account Linking - flows to safely link user accounts across identity providers.
  • Customization - override CSS styles of FirebaseUI to match your app requirements. Also, because FirebaseUI is open source, you can fork the project and customize it exactly to your needs.
  • One-tap sign-up and automatic sign-in - automatic integration with One-tap sign-up for fast cross-device sign-in.
  • Localized UI - internationalization for over 40 languages.
  • Upgrading anonymous users - ability to upgrade anonymous users through sign-in/sign-up. For more information, visit the Upgrading anonymous users section.

Before you begin

  1. Add Firebase Authentication to your web application.

  2. Include FirebaseUI via one of the following options:

    1. CDN

      Include the following script and CSS file in the <head> tag of your page, below the initialization snippet from the Firebase Console:

      <script src="https://cdn.firebase.com/libs/firebaseui/3.5.2/firebaseui.js"></script>
      <link type="text/css" rel="stylesheet" href="https://cdn.firebase.com/libs/firebaseui/3.5.2/firebaseui.css" />
      
    2. npm Module

      Install FirebaseUI and its dependencies via npm using the following command:

      $ npm install firebaseui --save
      

      require the following modules within your source files:

      var firebase = require('firebase');
      var firebaseui = require('firebaseui');
      
    3. Bower Component

      Install FirebaseUI and its dependencies via Bower using the following command:

      $ bower install firebaseui --save
      

      Include the required files in your HTML, if your HTTP Server serves the files within bower_components/:

      <script src="bower_components/firebaseui/dist/firebaseui.js"></script>
      <link type="text/css" rel="stylesheet" href="bower_components/firebaseui/dist/firebaseui.css" />
      

Set up sign-in methods

Before you can use Firebase to sign in users, you must enable and configure the sign-in methods you want to support.

Email address and password

  1. In the Firebase console, open the Authentication section and enable email and password authentication.

  2. Add the email provider ID to the list of FirebaseUI signInOptions.

    ui.start('#firebaseui-auth-container', {
      signInOptions: [
        firebase.auth.EmailAuthProvider.PROVIDER_ID
      ],
      // Other config options...
    });
    
  3. Optional: The EmailAuthProvider can be configured to require the user to enter a display name (defaults to true).

    ui.start('#firebaseui-auth-container', {
      signInOptions: [
        {
          provider: firebase.auth.EmailAuthProvider.PROVIDER_ID,
          requireDisplayName: false
        }
      ]
    });
    
  1. In the Firebase console, open the Authentication section. On the Sign in method tab, enable the Email/Password provider. Note that email/password sign-in must be enabled to use email link sign-in.

  2. In the same section, enable Email link (passwordless sign-in) sign-in method and click Save.

  3. Add the email provider ID to the list of FirebaseUI signInOptions along with the email link signInMethod.

    ui.start('#firebaseui-auth-container', {
      signInOptions: [
        {
          provider: firebase.auth.EmailAuthProvider.PROVIDER_ID,
          signInMethod: firebase.auth.EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD
        }
      ],
      // Other config options...
    });
    
  4. When rendering the sign-in UI conditionally (relevant for single page apps), use ui.isPendingRedirect() to detect if the URL corresponds to a sign-in with email link and the UI needs to be rendered to complete sign-in.

    // Is there an email link sign-in?
    if (ui.isPendingRedirect()) {
      ui.start('#firebaseui-auth-container', uiConfig);
    }
    // This can also be done via:
    if ((firebase.auth().isSignInWithEmailLink(window.location.href)) {
      ui.start('#firebaseui-auth-container', uiConfig);
    }
    
  5. Optional: The EmailAuthProvider for email link sign-in can be configured to allow or block the user from completing cross device sign-in.

    An optional emailLinkSignIn callback can be defined to return the firebase.auth.ActionCodeSettings configuration to use when sending the link. This provides the ability to specify how the link can be handled, custom dynamic link, additional state in the deep link, etc. When not provided, the current URL is used and a web only flow is triggered.

    Email link sign-in in FirebaseUI-web is compatible with FirebaseUI-Android and FirebaseUI-iOS where one user starting the flow from FirebaseUI-Android can open the link and complete sign-in with FirebaseUI-web. The same is true for the opposite flow.

    ui.start('#firebaseui-auth-container', {
      signInOptions: [
        {
          provider: firebase.auth.EmailAuthProvider.PROVIDER_ID,
          signInMethod: firebase.auth.EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD,
          // Allow the user the ability to complete sign-in cross device,
          // including the mobile apps specified in the ActionCodeSettings
          // object below.
          forceSameDevice: false,
          // Used to define the optional firebase.auth.ActionCodeSettings if
          // additional state needs to be passed along request and whether to open
          // the link in a mobile app if it is installed.
          emailLinkSignIn: function() {
            return {
              // Additional state showPromo=1234 can be retrieved from URL on
              // sign-in completion in signInSuccess callback by checking
              // window.location.href.
              url: 'https://www.example.com/completeSignIn?showPromo=1234',
              // Custom FDL domain.
              dynamicLinkDomain: 'example.page.link',
              // Always true for email link sign-in.
              handleCodeInApp: true,
              // Whether to handle link in iOS app if installed.
              iOS: {
                bundleId: 'com.example.ios'
              },
              // Whether to handle link in Android app if opened in an Android
              // device.
              android: {
                packageName: 'com.example.android',
                installApp: true,
                minimumVersion: '12'
              }
            };
          }
        }
      ]
    });
    

OAuth providers (Google, Facebook, Twitter and GitHub)

  1. In the Firebase console, open the Authentication section and enable the specified OAuth provider sign-in. Make sure the corresponding OAuth client ID and secret are also specified.

  2. Also in the Authentication section, make sure the domain where your sign-in page will be rendered is also whitelisted as an authorized domain.

  3. Add the OAuth provider ID to the list of FirebaseUI signInOptions.

    ui.start('#firebaseui-auth-container', {
      signInOptions: [
        // List of OAuth providers supported.
        firebase.auth.GoogleAuthProvider.PROVIDER_ID,
        firebase.auth.FacebookAuthProvider.PROVIDER_ID,
        firebase.auth.TwitterAuthProvider.PROVIDER_ID,
        firebase.auth.GithubAuthProvider.PROVIDER_ID
      ],
      // Other config options...
    });
    
  4. Optional: To specify custom scopes, or custom OAuth parameters per provider, you can pass an object instead of just the provider value:

    ui.start('#firebaseui-auth-container', {
      signInOptions = [
        {
          provider: firebase.auth.GoogleAuthProvider.PROVIDER_ID,
          scopes: [
            'https://www.googleapis.com/auth/contacts.readonly'
          ],
          customParameters: {
            // Forces account selection even when one account
            // is available.
            prompt: 'select_account'
          }
        },
        {
          provider: firebase.auth.FacebookAuthProvider.PROVIDER_ID,
          scopes: [
            'public_profile',
            'email',
            'user_likes',
            'user_friends'
          ],
          customParameters: {
            // Forces password re-entry.
            auth_type: 'reauthenticate'
          }
        },
        firebase.auth.TwitterAuthProvider.PROVIDER_ID, // Twitter does not support scopes.
        firebase.auth.EmailAuthProvider.PROVIDER_ID // Other providers don't need to be given as object.
      ]
    });
    

Phone number

  1. In the Firebase console, open the Authentication section and enable phone number sign-in.

  2. Make sure the domain where your sign-in page will be rendered is also whitelisted as an authorized domain.

  3. Add the phone number provider ID to the list of FirebaseUI signInOptions.

    ui.start('#firebaseui-auth-container', {
      signInOptions = [
        firebase.auth.PhoneAuthProvider.PROVIDER_ID
      ],
      // Other config options...
    });
    
  4. Optional: The PhoneAuthProvider can be configured with custom reCAPTCHA parameters whether reCAPTCHA is visible or invisible (defaults to normal). Refer to the reCAPTCHA API docs for more details.

    The default country to select in the phone number input can also be set. Refer to the list of supported country codes for the full list of codes. If unspecified, the phone number input will default to the United States (+1).

    The following options are currently supported.

    ui.start('#firebaseui-auth-container', {
      signInOptions = [
        {
          provider: firebase.auth.PhoneAuthProvider.PROVIDER_ID,
          recaptchaParameters: {
            type: 'image', // 'audio'
            size: 'normal', // 'invisible' or 'compact'
            badge: 'bottomleft' //' bottomright' or 'inline' applies to invisible.
          },
          defaultCountry: 'GB', // Set default country to the United Kingdom (+44).
          // For prefilling the national number, set defaultNationNumber.
          // This will only be observed if only phone Auth provider is used since
          // for multiple providers, the NASCAR screen will always render first
          // with a 'sign in with phone number' button.
          defaultNationalNumber: '1234567890',
          // You can also pass the full phone number string instead of the
          // 'defaultCountry' and 'defaultNationalNumber'. However, in this case,
          // the first country ID that matches the country code will be used to
          // populate the country selector. So for countries that share the same
          // country code, the selected country may not be the expected one.
          // In that case, pass the 'defaultCountry' instead to ensure the exact
          // country is selected. The 'defaultCountry' and 'defaultNationaNumber'
          // will always have higher priority than 'loginHint' which will be ignored
          // in their favor. In this case, the default country will be 'GB' even
          // though 'loginHint' specified the country code as '+1'.
          loginHint: '+11234567890'
        }
      ]
    });
    

Sign in

To kick off the FirebaseUI sign in flow, initialize the FirebaseUI instance by passing the underlying Auth instance.

// Initialize the FirebaseUI Widget using Firebase.
var ui = new firebaseui.auth.AuthUI(firebase.auth());

Define the HTML element where the FirebaseUI sign-in widget will be rendered.

<!-- The surrounding HTML is left untouched by FirebaseUI.
     Your app may use that space for branding, controls and other customizations.-->
<h1>Welcome to My Awesome App</h1>
<div id="firebaseui-auth-container"></div>
<div id="loader">Loading...</div>

Specify the FirebaseUI configuration (providers supported and UI customizations as well as success callbacks, etc).

var uiConfig = {
  callbacks: {
    signInSuccessWithAuthResult: function(authResult, redirectUrl) {
      // User successfully signed in.
      // Return type determines whether we continue the redirect automatically
      // or whether we leave that to developer to handle.
      return true;
    },
    uiShown: function() {
      // The widget is rendered.
      // Hide the loader.
      document.getElementById('loader').style.display = 'none';
    }
  },
  // Will use popup for IDP Providers sign-in flow instead of the default, redirect.
  signInFlow: 'popup',
  signInSuccessUrl: '<url-to-redirect-to-on-success>',
  signInOptions: [
    // Leave the lines as is for the providers you want to offer your users.
    firebase.auth.GoogleAuthProvider.PROVIDER_ID,
    firebase.auth.FacebookAuthProvider.PROVIDER_ID,
    firebase.auth.TwitterAuthProvider.PROVIDER_ID,
    firebase.auth.GithubAuthProvider.PROVIDER_ID,
    firebase.auth.EmailAuthProvider.PROVIDER_ID,
    firebase.auth.PhoneAuthProvider.PROVIDER_ID
  ],
  // Terms of service url.
  tosUrl: '<your-tos-url>',
  // Privacy policy url.
  privacyPolicyUrl: '<your-privacy-policy-url>'
};

Finally, render the FirebaseUI Auth interface:

// The start method will wait until the DOM is loaded.
ui.start('#firebaseui-auth-container', uiConfig);

Upgrading anonymous users

Enabling anonymous user upgrade

When an anonymous user signs in or signs up with a permanent account, you want to be sure the user can continue with what they were doing before signing up. To do so, simply set autoUpgradeAnonymousUsers to true when you configure the sign-in UI (this option is disabled by default).

Handling anonymous user upgrade merge conflicts

There are cases when a user, initially signed in anonymously, tries to upgrade to an existing Firebase user. Since an existing user cannot be linked to another existing user, FirebaseUI will trigger the signInFailure callback with an error code firebaseui/anonymous-upgrade-merge-conflict when the above occurs. The error object will also contain the permanent credential. Sign-in with the permanent credential should be triggered in the callback to complete sign-in. Before sign-in can be completed via auth.signInWithCredential(error.credential), you must save the anonymous user's data and delete the anonymous user. Then, after sign-in completion, copy the data back to the non-anonymous user. An example below illustrates how this flow would work.

// Temp variable to hold the anonymous user data if needed.
var data = null;
// Hold a reference to the anonymous current user.
var anonymousUser = firebase.auth().currentUser;
ui.start('#firebaseui-auth-container', {
  // Whether to upgrade anonymous users should be explicitly provided.
  // The user must already be signed in anonymously before FirebaseUI is
  // rendered.
  autoUpgradeAnonymousUsers: true,
  signInSuccessUrl: '<url-to-redirect-to-on-success>',
  signInOptions: [
    firebase.auth.GoogleAuthProvider.PROVIDER_ID,
    firebase.auth.FacebookAuthProvider.PROVIDER_ID,
    firebase.auth.EmailAuthProvider.PROVIDER_ID,
    firebase.auth.PhoneAuthProvider.PROVIDER_ID
  ],
  callbacks: {
    // signInFailure callback must be provided to handle merge conflicts which
    // occur when an existing credential is linked to an anonymous user.
    signInFailure: function(error) {
      // For merge conflicts, the error.code will be
      // 'firebaseui/anonymous-upgrade-merge-conflict'.
      if (error.code != 'firebaseui/anonymous-upgrade-merge-conflict') {
        return Promise.resolve();
      }
      // The credential the user tried to sign in with.
      var cred = error.credential;
      // Copy data from anonymous user to permanent user and delete anonymous
      // user.
      // ...
      // Finish sign-in after data is copied.
      return firebase.auth().signInWithCredential(cred);
    }
  }
});

Next Steps

  • For more information on using and customizing FirebaseUI, visit the README.
  • If you find an issue in FirebaseUI and would like to report it, use the GitHub issue tracker.

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