Manage Users in Firebase

Create a user

You create a new user in your Firebase project by calling the createUserWithEmail:password:completion: method or by signing in a user for the first time using a federated identity provider, such as Google Sign-In or Facebook Login.

You can also create new password-authenticated users from the Authentication section of the Firebase console, on the Users page.

Get the currently signed-in user

The recommended way to get the current user is by setting a listener on the Auth object:

Swift

handle = Auth.auth().addStateDidChangeListener { (auth, user) in
  // ...
}

Objective-C

self.handle = [[FIRAuth auth]
    addAuthStateDidChangeListener:^(FIRAuth *_Nonnull auth, FIRUser *_Nullable user) {
      // ...
    }];

By using a listener, you ensure that the Auth object isn't in an intermediate state—such as initialization—when you get the current user.

You can also get the currently signed-in user by using the currentUser property. If a user isn't signed in, currentUser is nil:

Swift

if Auth.auth().currentUser != nil {
  // User is signed in.
  // ...
} else {
  // No user is signed in.
  // ...
}

Objective-C

if ([FIRAuth auth].currentUser) {
  // User is signed in.
  // ...
} else {
  // No user is signed in.
  // ...
}

Get a user's profile

To get a user's profile information, use the properties of an instance of FIRUser. For example:

Swift

let user = Auth.auth().currentUser
if let user = user {
  // The user's ID, unique to the Firebase project.
  // Do NOT use this value to authenticate with your backend server,
  // if you have one. Use getTokenWithCompletion:completion: instead.
  let uid = user.uid
  let email = user.email
  let photoURL = user.photoURL
  var multiFactorString = "MultiFactor: "
  for info in user.multiFactor.enrolledFactors {
    multiFactorString += info.displayName ?? "[DispayName]"
    multiFactorString += " "
  }
  // ...
}

Objective-C

FIRUser *user = [FIRAuth auth].currentUser;
if (user) {
  // The user's ID, unique to the Firebase project.
  // Do NOT use this value to authenticate with your backend server,
  // if you have one. Use getTokenWithCompletion:completion: instead.
  NSString *email = user.email;
  NSString *uid = user.uid;
  NSMutableString *multiFactorString = [NSMutableString stringWithFormat:@"MultiFactor: "];
  for (FIRMultiFactorInfo *info in user.multiFactor.enrolledFactors) {
    [multiFactorString appendString:info.displayName];
    [multiFactorString appendString:@" "];
  }
  NSURL *photoURL = user.photoURL;
  // ...
}

Get a user's provider-specific profile information

To get the profile information retrieved from the sign-in providers linked to a user, use the providerData property. For example:

Swift

let userInfo = Auth.auth().currentUser?.providerData[indexPath.row]
cell?.textLabel?.text = userInfo?.providerID
// Provider-specific UID
cell?.detailTextLabel?.text = userInfo?.uid

Objective-C

id<FIRUserInfo> userInfo = [FIRAuth auth].currentUser.providerData[indexPath.row];
cell.textLabel.text = [userInfo providerID];
// Provider-specific UID
cell.detailTextLabel.text = [userInfo uid];

Update a user's profile

You can update a user's basic profile information—the user's display name and profile photo URL—with the FIRUserProfileChangeRequest class. For example:

Swift

let changeRequest = Auth.auth().currentUser?.createProfileChangeRequest()
changeRequest?.displayName = displayName
changeRequest?.commitChanges { (error) in
  // ...
}

Objective-C

FIRUserProfileChangeRequest *changeRequest = [[FIRAuth auth].currentUser profileChangeRequest];
changeRequest.displayName = userInput;
[changeRequest commitChangesWithCompletion:^(NSError *_Nullable error) {
  // ...
}];

Set a user's email address

You can set a user's email address with the updateEmail:completion: method. For example:

Swift

Auth.auth().currentUser?.updateEmail(to: email) { (error) in
  // ...
}

Objective-C

[[FIRAuth auth].currentUser updateEmail:userInput completion:^(NSError *_Nullable error) {
  // ...
}];

Send a user a verification email

You can send an address verification email to a user with the sendEmailVerificationWithCompletion: method. For example:

Swift

Auth.auth().currentUser?.sendEmailVerification { (error) in
  // ...
}

Objective-C

[[FIRAuth auth].currentUser sendEmailVerificationWithCompletion:^(NSError *_Nullable error) {
  // ...
}];

You can customize the email template that is used in Authentication section of the Firebase console, on the Email Templates page. See Email Templates in Firebase Help Center.

It is also possible to pass state via a continue URL to redirect back to the app when sending a verification email.

Additionally you can localize the verification email by updating the language code on the Auth instance before sending the email. For example:

Swift

Auth.auth().languageCode = "fr"
// To apply the default app language instead of explicitly setting it.
// Auth.auth().useAppLanguage()

Objective-C

[FIRAuth auth].languageCode = @"fr";
// To apply the default app language instead of explicitly setting it.
// [[FIRAuth auth] useAppLanguage];

Set a user's password

You can set a user's password with the updatePassword:completion: method. For example:

Swift

Auth.auth().currentUser?.updatePassword(to: password) { (error) in
  // ...
}

Objective-C

[[FIRAuth auth].currentUser updatePassword:userInput completion:^(NSError *_Nullable error) {
  // ...
}];

Send a password reset email

You can send a password reset email to a user with the sendPasswordResetWithEmail:completion: method. For example:

Swift

Auth.auth().sendPasswordReset(withEmail: email) { error in
  // ...
}

Objective-C

[[FIRAuth auth] sendPasswordResetWithEmail:userInput completion:^(NSError *_Nullable error) {
  // ...
}];

You can customize the email template that is used in Authentication section of the Firebase console, on the Email Templates page. See Email Templates in Firebase Help Center.

It is also possible to pass state via a continue URL to redirect back to the app when sending a password reset email.

Additionally you can localize the password reset email by updating the language code on the Auth instance before sending the email. For example:

Swift

Auth.auth().languageCode = "fr"
// To apply the default app language instead of explicitly setting it.
// Auth.auth().useAppLanguage()

Objective-C

[FIRAuth auth].languageCode = @"fr";
// To apply the default app language instead of explicitly setting it.
// [[FIRAuth auth] useAppLanguage];

You can also send password reset emails from the Firebase console.

Delete a user

You can delete a user account with the deleteWithCompletion method. For example:

Swift

let user = Auth.auth().currentUser

user?.delete { error in
  if let error = error {
    // An error happened.
  } else {
    // Account deleted.
  }
}

Objective-C

FIRUser *user = [FIRAuth auth].currentUser;

[user deleteWithCompletion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // Account deleted.
  }
}];

You can also delete users from the Authentication section of the Firebase console, on the Users page.

Re-authenticate a user

Some security-sensitive actions—such as deleting an account, setting a primary email address, and changing a password—require that the user has recently signed in. If you perform one of these actions, and the user signed in too long ago, the action fails with the FIRAuthErrorCodeCredentialTooOld error. When this happens, re-authenticate the user by getting new sign-in credentials from the user and passing the credentials to reauthenticate. For example:

Swift

let user = Auth.auth().currentUser
var credential: AuthCredential

// Prompt the user to re-provide their sign-in credentials

user?.reauthenticate(with: credential) { error in
  if let error = error {
    // An error happened.
  } else {
    // User re-authenticated.
  }
}

Objective-C

FIRUser *user = [FIRAuth auth].currentUser;
FIRAuthCredential *credential;

// Prompt the user to re-provide their sign-in credentials

[user reauthenticateWithCredential:credential completion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // User re-authenticated.
  }
}];

Import user accounts

You can import user accounts from a file into your Firebase project by using the Firebase CLI's auth:import command. For example:

firebase auth:import users.json --hash-algo=scrypt --rounds=8 --mem-cost=14