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:

[[FIRAuth auth] addAuthStateDidChangeListener:^(FIRAuth *_Nonnull auth,
                                                FIRUser *_Nullable user) {
  if (user != nil) {
    // User is signed in.
  } else {
    // No user is signed in.
  }
}];

FIRAuth.auth()?.addAuthStateDidChangeListener { auth, user in
  if let user = user {
    // User is signed in.
  } else {
    // No user is signed in.
  }
}

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:

FIRUser *user = [FIRAuth auth].currentUser;

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

if let user = 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:

FIRUser *user = [FIRAuth auth].currentUser;

if (user != nil) {
  NSString *name = user.displayName;
  NSString *email = user.email;
  NSURL *photoUrl = user.photoURL;
  NSString *uid = user.uid;  // 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.
} else {
  // No user is signed in.
}

if let user = FIRAuth.auth()?.currentUser {
  let name = user.displayName
  let email = user.email
  let photoUrl = user.photoURL
  let uid = user.uid;  // 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.
} else {
  // No user is signed in.
}

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:

FIRUser *user = [FIRAuth auth].currentUser;

if (user != nil) {
  for (FIRUserInfo *profile in user.providerData) {
    NSString *providerID = profile.providerID;
    NSString *uid = profile.uid;  // Provider-specific UID
    NSString *name = profile.displayName;
    NSString *email = profile.email;
    NSURL *photoURL = profile.photoURL;
  }
} else {
  // No user is signed in.
}

if let user = FIRAuth.auth()?.currentUser {
  for profile in user.providerData {
    let providerID = profile.providerID
    let uid = profile.uid;  // Provider-specific UID
    let name = profile.displayName
    let email = profile.email
    let photoURL = profile.photoURL
  }
} else {
  // No user is signed in.
}

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:

FIRUser *user = [FIRAuth auth].currentUser;
FIRUserProfileChangeRequest *changeRequest = [user profileChangeRequest];

changeRequest.displayName = @"Jane Q. User";
changeRequest.photoURL =
    [NSURL URLWithString:@"https://example.com/jane-q-user/profile.jpg"];
[changeRequest commitChangesWithCompletion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // Profile updated.
  }
}];

let user = FIRAuth.auth()?.currentUser
if let user = user {
  let changeRequest = user.profileChangeRequest()

  changeRequest.displayName = "Jane Q. User"
  changeRequest.photoURL =
      NSURL(string: "https://example.com/jane-q-user/profile.jpg")
  changeRequest.commitChangesWithCompletion { error in
    if let error = error {
      // An error happened.
    } else {
      // Profile updated.
    }
  }
}

Set a user's email address

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

FIRUser *user = [FIRAuth auth].currentUser;

[user updateEmail:@"user@example.com" completion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // Email updated.
  }
}];

let user = FIRAuth.auth()?.currentUser

user?.updateEmail("user@example.com") { error in
  if let error = error {
    // An error happened.
  } else {
    // Email updated.
  }
}

Send a user a verification email

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

FIRUser *user = [FIRAuth auth].currentUser;

[user sendEmailVerificationWithCompletion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // Email sent.
  }
}];

let user = FIRAuth.auth()?.currentUser

user?.sendEmailVerificationWithCompletion() { error in
  if let error = error {
    // An error happened.
  } else {
    // Email sent.
  }
}

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.

Set a user's password

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

FIRUser *user = [FIRAuth auth].currentUser;
NSString *newPassword = [yourApp getRandomSecurePassword];

[user updatePassword:newPassword completion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // Password updated.
  }
}];

let user = FIRAuth.auth()?.currentUser
let newPassword = getRandomSecurePassword()

user?.updatePassword(newPassword) { error in
  if let error = error {
    // An error happened.
  } else {
    // Password updated.
  }
}

Send a password reset email

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

NSString *email = @"user@example.com";

[[FIRAuth auth] sendPasswordResetWithEmail:email
                                completion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // Password reset email sent.
  }
}];

let email = "user@example.com"

FIRAuth.auth()?.sendPasswordResetWithEmail(email) { error in
  if let error = error {
    // An error happened.
  } else {
    // Password reset email sent.
  }
}

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.

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:

FIRUser *user = [FIRAuth auth].currentUser;

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

let user = FIRAuth.auth()?.currentUser

user?.deleteWithCompletion { error in
  if let error = 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:

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.
  }
}];

let user = FIRAuth.auth()?.currentUser
var credential: FIRAuthCredential

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

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