readme.md

Get user_pseudo_id from Firebase client SDK

For Firebase installation ID (FID) or migrate from Instance ID to FID, please consult here.

Retrive client ID (a.k.a. user_pseudo_id or instance id)

Swift

do {
  let id = try await Installations.installations().installationID()
  print("Installation ID: \(id)")
} catch {
  print("Error fetching id: \(error)")
}

Objective-C

[[FIRInstallations installations] installationIDWithCompletion:^(NSString *identifier, NSError *error) {
  if (error != nil) {
    NSLog(@"Error fetching Installation ID %@", error);
    return;
  }
  NSLog(@"Installation ID: %@", identifier);
}];

Java Android

FirebaseInstallations.getInstance().getId()
        .addOnCompleteListener(new OnCompleteListener<String>() {
    @Override
    public void onComplete(@NonNull Task<String> task) {
        if (task.isSuccessful()) {
            Log.d("Installations", "Installation ID: " + task.getResult());
        } else {
            Log.e("Installations", "Unable to get Installation ID");
        }
    }
});

Kotlin+KTX Android

FirebaseInstallations.getInstance().id.addOnCompleteListener { task ->
    if (task.isSuccessful) {
        Log.d("Installations", "Installation ID: " + task.result)
    } else {
        Log.e("Installations", "Unable to get Installation ID")
    }
}

JavaScript

const installationId = await firebase.installations().getId();
console.log(installationId);

Dart Flutter

String id = await FirebaseInstallations.instance.getId();

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Deprecated methods

Mobile clients

Firebase Docs

• Android: public Task getAppInstanceId ()
• iOS: appInstanceID()

Example for Android

FirebaseAnalytics.getInstance(this).getAppInstanceId().addOnCompleteListener(new OnCompleteListener<String>() {
    @Override
    public void onComplete(@NonNull Task<String> task) {
        if (task.isSuccessful()) {
            String user_pseudo_id = task.getResult();
        }
    }
});

Web

JavaScript

var gaUserId = document.cookie.match(/_ga=(.+?);/)[1].split('.').slice(-2).join(".")

PHP

$gaUserId = preg_replace("/^.+\.(.+?\..+?)$/", "\\1", @$_COOKIE['_ga']);