Authenticate with Firebase Anonymously on Apple Platforms
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You can useFirebase Authenticationto create and use temporary anonymous accounts
to authenticate with Firebase. These temporary anonymous accounts can be used to
allow users who haven't yet signed up to your app to work with data protected
by security rules. If an anonymous user decides to sign up to your app, you canlink their sign-in credentials to the anonymous
accountso that they can continue to work with their protected data in
future sessions.
Before you begin
Use Swift Package Manager to install and manage Firebase dependencies.
In Xcode, with your app project open, navigate toFile > Add Packages.
When prompted, add the Firebase Apple platforms SDK repository:
https://github.com/firebase/firebase-ios-sdk.git
Choose theFirebase Authenticationlibrary.
Add the-ObjCflag to theOther Linker Flagssection of your target's build settings.
When finished, Xcode will automatically begin resolving and downloading your
dependencies in the background.
If you haven't yet connected your app to your Firebase project, do so from
theFirebaseconsole.
On theSign-in Methodspage, enable theAnonymoussign-in method.
Optional: If you've upgraded your project toFirebase Authenticationwith Identity Platform, you can enable automatic clean-up. When
you enable this setting, anonymous accounts older than 30 days will be automatically
deleted. In projects with automatic clean-up enabled, anonymous authentication will no
longer count toward usage limits or billing quotas. SeeAutomatic clean-up.
Authenticate with Firebase anonymously
When a signed-out user uses an app feature that requires authentication with
Firebase, sign in the user anonymously by completing the following steps:
Import theFirebaseCoremodule in yourUIApplicationDelegate, as well as any otherFirebase modulesyour app delegate uses.
For example, to useCloud FirestoreandAuthentication:
Configure aFirebaseAppshared instance in your app delegate'sapplication(_:didFinishLaunchingWithOptions:)method:
SwiftUI
// Use Firebase library to configure APIsFirebaseApp.configure()
Swift
// Use Firebase library to configure APIsFirebaseApp.configure()
Objective-C
// Use Firebase library to configure APIs[FIRAppconfigure];
If you're using SwiftUI, you must create an application delegate and attach it
to yourAppstruct viaUIApplicationDelegateAdaptororNSApplicationDelegateAdaptor. You must also disable app delegate swizzling. For
more information, see theSwiftUI instructions.
SwiftUI
@mainstructYourApp:App{// register app delegate for Firebase setup@UIApplicationDelegateAdaptor(AppDelegate.self)vardelegatevarbody:someScene{WindowGroup{NavigationView{ContentView()}}}}
Convert an anonymous account to a permanent account
When an anonymous user signs up to your app, you might want to allow them to
continue their work with their new account—for example, you might want to
make the items the user added to their shopping cart before they signed up
available in their new account's shopping cart. To do so, complete the following
steps:
When the user signs up, complete the sign-in flow for the user's
authentication provider up to, but not including, calling one of theFIRAuth.signInWithmethods. For example, get the user's Google ID token,
Facebook access token, or email address and password.
Get anFIRAuthCredentialfor the new authentication provider:
If the call tolinkWithCredential:completion:succeeds, the user's new account can
access the anonymous account's Firebase data.
Automatic clean-up
If you've upgraded your project toFirebase Authenticationwith Identity Platform, you can
enable automatic clean-up in theFirebaseconsole. When you enable this feature you allow
Firebase to automatically delete anonymous accounts older than 30 days. In projects with automatic
clean-up enabled, anonymous authentication will not count toward usage limits or billing quotas.
Any anonymous accounts created after enabling automatic clean-up might be automatically
deleted any time after 30 days post-creation.
Existing anonymous accounts will be eligible for automatic deletion 30 days after
enabling automatic clean-up.
If you turn automatic clean-up off, any anonymous accounts scheduled to be deleted will remain
scheduled to be deleted.
If you "upgrade" an anonymous account by linking it to any sign-in method, the account will
not get automatically deleted.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[],[],null,["You can use Firebase Authentication to create and use temporary anonymous accounts\nto authenticate with Firebase. These temporary anonymous accounts can be used to\nallow users who haven't yet signed up to your app to work with data protected\nby security rules. If an anonymous user decides to sign up to your app, you can\n[link their sign-in credentials to the anonymous\naccount](/docs/auth/ios/account-linking) so that they can continue to work with their protected data in\nfuture sessions.\n\nBefore you begin\n\n1. Use Swift Package Manager to install and manage Firebase dependencies.\n\n | Visit [our installation guide](/docs/ios/installation-methods) to learn about the different ways you can add Firebase SDKs to your Apple project, including importing frameworks directly and using CocoaPods.\n 1. In Xcode, with your app project open, navigate to **File \\\u003e Add Packages**.\n 2. When prompted, add the Firebase Apple platforms SDK repository: \n\n ```text\n https://github.com/firebase/firebase-ios-sdk.git\n ```\n | **Note:** New projects should use the default (latest) SDK version, but you can choose an older version if needed.\n 3. Choose the Firebase Authentication library.\n 4. Add the `-ObjC` flag to the *Other Linker Flags* section of your target's build settings.\n 5. When finished, Xcode will automatically begin resolving and downloading your dependencies in the background.\n2. If you haven't yet connected your app to your Firebase project, do so from the [Firebase console](//console.firebase.google.com/).\n3. Enable anonymous auth:\n 1. In the [Firebase console](//console.firebase.google.com/), open the **Auth** section.\n 2. On the **Sign-in Methods** page, enable the **Anonymous** sign-in method.\n 3. **Optional** : If you've upgraded your project to [Firebase Authentication with Identity Platform](/auth#identity-platform), you can enable automatic clean-up. When you enable this setting, anonymous accounts older than 30 days will be automatically deleted. In projects with automatic clean-up enabled, anonymous authentication will no longer count toward usage limits or billing quotas. See [Automatic clean-up](#auto-cleanup).\n\nAuthenticate with Firebase anonymously\n\nWhen a signed-out user uses an app feature that requires authentication with\nFirebase, sign in the user anonymously by completing the following steps:\n\n1. Import the `FirebaseCore` module in your `UIApplicationDelegate`, as well as any other [Firebase modules](/docs/ios/setup#available-pods) your app delegate uses. For example, to use Cloud Firestore and Authentication: \n\n SwiftUI \n\n ```swift\n import SwiftUI\n import FirebaseCore\n import FirebaseFirestore\n import FirebaseAuth\n // ...\n \n ```\n\n Swift \n\n ```swift\n import FirebaseCore\n import FirebaseFirestore\n import FirebaseAuth\n // ...\n \n ```\n\n Objective-C \n\n ```objective-c\n @import FirebaseCore;\n @import FirebaseFirestore;\n @import FirebaseAuth;\n // ...\n \n ```\n2. Configure a [`FirebaseApp`](/docs/reference/swift/firebasecore/api/reference/Classes/FirebaseApp) shared instance in your app delegate's `application(_:didFinishLaunchingWithOptions:)` method: \n\n SwiftUI \n\n ```swift\n // Use Firebase library to configure APIs\n FirebaseApp.configure()\n ```\n\n Swift \n\n ```swift\n // Use Firebase library to configure APIs\n FirebaseApp.configure()\n ```\n\n Objective-C \n\n ```objective-c\n // Use Firebase library to configure APIs\n [FIRApp configure];\n ```\n3. If you're using SwiftUI, you must create an application delegate and attach it to your `App` struct via `UIApplicationDelegateAdaptor` or `NSApplicationDelegateAdaptor`. You must also disable app delegate swizzling. For more information, see the [SwiftUI instructions](/docs/ios/learn-more#swiftui). \n\n SwiftUI \n\n ```swift\n @main\n struct YourApp: App {\n // register app delegate for Firebase setup\n @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate\n\n var body: some Scene {\n WindowGroup {\n NavigationView {\n ContentView()\n }\n }\n }\n }\n \n ```\n4. Call the `signInAnonymouslyWithCompletion:` method: \n\n Swift \n\n ```swift\n Auth.auth().signInAnonymously { authResult, error in\n // ...\n }\n ```\n\n Objective-C \n\n ```objective-c\n [[FIRAuth auth] signInAnonymouslyWithCompletion:^(FIRAuthDataResult * _Nullable authResult,\n NSError * _Nullable error) {\n // ...\n }];\n ```\n5. If the `signInAnonymouslyWithCompletion:` method completes without error, you can get the anonymous user's account data from the `FIRAuthDataResult` object: \n\n Swift \n\n ```swift\n guard let user = authResult?.user else { return }\n let isAnonymous = user.isAnonymous // true\n let uid = user.uid\n ```\n\n Objective-C \n\n ```objective-c\n FIRUser *user = authResult.user;\n BOOL isAnonymous = user.anonymous; // YES\n NSString *uid = user.uid;\n ```\n\n| To protect your project from abuse, Firebase limits the number of new email/password and anonymous sign-ups that your application can have from the same IP address in a short period of time. You can request and schedule temporary changes to this quota from the [Firebase console](//console.firebase.google.com/project/_/authentication/providers).\n\nConvert an anonymous account to a permanent account\n\nWhen an anonymous user signs up to your app, you might want to allow them to\ncontinue their work with their new account---for example, you might want to\nmake the items the user added to their shopping cart before they signed up\navailable in their new account's shopping cart. To do so, complete the following\nsteps:\n\n1. When the user signs up, complete the sign-in flow for the user's authentication provider up to, but not including, calling one of the [`FIRAuth.signInWith`](/docs/reference/ios/firebaseauth/interface_f_i_r_auth) methods. For example, get the user's Google ID token, Facebook access token, or email address and password.\n2. Get an `FIRAuthCredential` for the new authentication provider:\n\n Google Sign-In \n\n Swift \n\n ```swift\n guard\n let authentication = user?.authentication,\n let idToken = authentication.idToken\n else {\n return\n }\n\n let credential = GoogleAuthProvider.credential(withIDToken: idToken,\n accessToken: authentication.accessToken)\n ```\n\n Objective-C \n\n ```objective-c\n FIRAuthCredential *credential =\n [FIRGoogleAuthProvider credentialWithIDToken:result.user.idToken.tokenString\n accessToken:result.user.accessToken.tokenString];\n ```\n\n Facebook Login \n\n Swift \n\n ```swift\n let credential = FacebookAuthProvider\n .credential(withAccessToken: AccessToken.current!.tokenString)\n ```\n\n Objective-C \n\n ```objective-c\n FIRAuthCredential *credential = [FIRFacebookAuthProvider\n credentialWithAccessToken:[FBSDKAccessToken currentAccessToken].tokenString];\n ```\n\n Email-password sign-in \n\n Swift \n\n ```swift\n let credential = EmailAuthProvider.credential(withEmail: email, password: password)\n ```\n\n Objective-C \n\n ```objective-c\n FIRAuthCredential *credential =\n [FIREmailAuthProvider credentialWithEmail:email\n password:password];\n ```\n3. Pass the `FIRAuthCredential` object to the sign-in user's\n `linkWithCredential:completion:` method:\n\n Swift \n\n ```swift\n user.link(with: credential) { authResult, error in\n // ...\n }\n }\n ```\n\n Objective-C \n\n ```objective-c\n [[FIRAuth auth].currentUser linkWithCredential:credential\n completion:^(FIRAuthDataResult *result, NSError *_Nullable error) {\n // ...\n }];\n ```\n\nIf the call to `linkWithCredential:completion:` succeeds, the user's new account can\naccess the anonymous account's Firebase data.\n| This technique can also be used to [link any two accounts](/docs/auth/ios/account-linking).\n\nAutomatic clean-up\n\nIf you've upgraded your project to [Firebase Authentication with Identity Platform](/docs/auth#identity-platform), you can\nenable automatic clean-up in the Firebase console. When you enable this feature you allow\nFirebase to automatically delete anonymous accounts older than 30 days. In projects with automatic\nclean-up enabled, anonymous authentication will not count toward usage limits or billing quotas.\n\n- Any anonymous accounts created after enabling automatic clean-up might be automatically deleted any time after 30 days post-creation.\n- Existing anonymous accounts will be eligible for automatic deletion 30 days after enabling automatic clean-up.\n- If you turn automatic clean-up off, any anonymous accounts scheduled to be deleted will remain scheduled to be deleted.\n- If you \"upgrade\" an anonymous account by linking it to any sign-in method, the account will not get automatically deleted.\n\nIf you want to see how many users will be affected before you enable this feature, and you've\nupgraded your project to [Firebase Authentication with Identity Platform](/docs/auth#identity-platform), you can filter by\n`is_anon` in [Cloud\nLogging](https://cloud.google.com/logging/docs).\n\nNext steps\n\nNow that users can authenticate with Firebase, you can control their access to\ndata in your Firebase database using\n[Firebase rules](/docs/database/security#section-authorization)."]]
