How to find serial number of Android device?

Question

I need to use a unique ID for an Android app and I thought the serial number for the device would be a good candidate. How do I retrieve the serial number of an Android device in my app ?

Answer 1

Another way is to use /sys/class/android_usb/android0/iSerial in an App with no permissions whatsoever.

user@creep:~$ adb shell ls -l /sys/class/android_usb/android0/iSerial
-rw-r--r-- root     root         4096 2013-01-10 21:08 iSerial
user@creep:~$ adb shell cat /sys/class/android_usb/android0/iSerial
0A3CXXXXXXXXXX5

To do this in java one would just use a FileInputStream to open the iSerial file and read out the characters. Just be sure you wrap it in an exception handler because not all devices have this file.

At least the following devices are known to have this file world-readable:

• Galaxy Nexus
• Nexus S
• Motorola Xoom 3g
• Toshiba AT300
• HTC One V
• Mini MK802
• Samsung Galaxy S II

You can also see my blog post here: http://insitusec.blogspot.com/2013/01/leaking-android-hardware-serial-number.html where I discuss what other files are available for info.

Answer 2

I know this question is old but it can be done in one line of code

String deviceID = Build.SERIAL;

Answer 3

String deviceId = Settings.System.getString(getContentResolver(),
                                Settings.System.ANDROID_ID);

Although, it is not guaranteed that the Android ID will be an unique identifier.

Answer 4

There are problems with all the above approaches. At Google i/o Reto Meier released a robust answer to how to approach this which should meet most developers needs to track users across installations.

This approach will give you an anonymous, secure user ID which will be persistent for the user across different devices (including tablets, based on primary Google account) and across installs on the same device. The basic approach is to generate a random user ID and to store this in the apps shared preferences. You then use Google's backup agent to store the shared preferences linked to the Google account in the cloud.

Lets go through the full approach. First we need to create a backup for our SharedPreferences using the Android Backup Service. Start by registering your app via this link: http://developer.android.com/google/backup/signup.html

Google will give you a backup service key which you need to add to the manifest. You also need to tell the application to use the BackupAgent as follows:

<application android:label="MyApplication"
         android:backupAgent="MyBackupAgent">
    ...
    <meta-data android:name="com.google.android.backup.api_key"
        android:value="your_backup_service_key" />
</application>

Then you need to create the backup agent and tell it to use the helper agent for sharedpreferences:

public class MyBackupAgent extends BackupAgentHelper {
    // The name of the SharedPreferences file
    static final String PREFS = "user_preferences";

    // A key to uniquely identify the set of backup data
    static final String PREFS_BACKUP_KEY = "prefs";

    // Allocate a helper and add it to the backup agent
    @Override
    public void onCreate() {
        SharedPreferencesBackupHelper helper = new SharedPreferencesBackupHelper(this,          PREFS);
        addHelper(PREFS_BACKUP_KEY, helper);
    }
}

To complete the backup you need to create an instance of BackupManager in your main Activity:

BackupManager backupManager = new BackupManager(context);

Finally create a user ID, if it doesn't already exist, and store it in the SharedPreferences:

  public static String getUserID(Context context) {
            private static String uniqueID = null;
        private static final String PREF_UNIQUE_ID = "PREF_UNIQUE_ID";
    if (uniqueID == null) {
        SharedPreferences sharedPrefs = context.getSharedPreferences(
                MyBackupAgent.PREFS, Context.MODE_PRIVATE);
        uniqueID = sharedPrefs.getString(PREF_UNIQUE_ID, null);
        if (uniqueID == null) {
            uniqueID = UUID.randomUUID().toString();
            Editor editor = sharedPrefs.edit();
            editor.putString(PREF_UNIQUE_ID, uniqueID);
            editor.commit();

            //backup the changes
            BackupManager mBackupManager = new BackupManager(context);
            mBackupManager.dataChanged();
        }
    }

    return uniqueID;
}

This User_ID will now be persistent across installations, even if the user switches devices.

For more information on this approach see Reto's talk here http://www.google.com/events/io/2011/sessions/android-protips-advanced-topics-for-expert-android-app-developers.html

And for full details of how to implement the backup agent see the developer site here: http://developer.android.com/guide/topics/data/backup.html I particularly recommend the section at the bottom on testing as the backup does not happen instantaneously and so to test you have to force the backup.

Answer 5

I found the example class posted by @emmby above to be a great starting point. But it has a couple of flaws, as mentioned by other posters. The major one is that it persists the UUID to an XML file unnecessarily and thereafter always retrieves it from this file. This lays the class open to an easy hack: anyone with a rooted phone can edit the XML file to give themselves a new UUID.

I've updated the code so that it only persists to XML if absolutely necessary (i.e. when using a randomly generated UUID) and re-factored the logic as per @Brill Pappin's answer:

import android.content.Context;
import android.content.SharedPreferences;
import android.provider.Settings.Secure;
import android.telephony.TelephonyManager;

import java.io.UnsupportedEncodingException;
import java.util.UUID;

public class DeviceUuidFactory {
    protected static final String PREFS_FILE = "device_id.xml";
    protected static final String PREFS_DEVICE_ID = "device_id";

    protected static UUID uuid;

    public DeviceUuidFactory(Context context) {

        if( uuid ==null ) {
            synchronized (DeviceUuidFactory.class) {
                if( uuid == null) {
                    final SharedPreferences prefs = context.getSharedPreferences( PREFS_FILE, 0);
                    final String id = prefs.getString(PREFS_DEVICE_ID, null );

                    if (id != null) {
                        // Use the ids previously computed and stored in the prefs file
                        uuid = UUID.fromString(id);

                    } else {

                        final String androidId = Secure.getString(context.getContentResolver(), Secure.ANDROID_ID);

                        // Use the Android ID unless it's broken, in which case fallback on deviceId,
                        // unless it's not available, then fallback on a random number which we store
                        // to a prefs file
                        try {
                             if ( "9774d56d682e549c".equals(androidId) || (androidId == null) ) {
                                final String deviceId = ((TelephonyManager) context.getSystemService( Context.TELEPHONY_SERVICE )).getDeviceId();

                                if (deviceId != null)
                                {
                                    uuid = UUID.nameUUIDFromBytes(deviceId.getBytes("utf8"));
                                }
                                else
                                {
                                    uuid = UUID.randomUUID();

                                    // Write the value out to the prefs file so it persists
                                    prefs.edit().putString(PREFS_DEVICE_ID, uuid.toString() ).commit();
                                }
                            }
                            else
                            {
                                uuid = UUID.nameUUIDFromBytes(androidId.getBytes("utf8"));
                            } 
                        } catch (UnsupportedEncodingException e) {
                            throw new RuntimeException(e);
                        }



                    }

                }
            }
        }

    }


    /**
     * Returns a unique UUID for the current android device.  As with all UUIDs, this unique ID is "very highly likely"
     * to be unique across all Android devices.  Much more so than ANDROID_ID is.
     *
     * The UUID is generated by using ANDROID_ID as the base key if appropriate, falling back on
     * TelephonyManager.getDeviceID() if ANDROID_ID is known to be incorrect, and finally falling back
     * on a random UUID that's persisted to SharedPreferences if getDeviceID() does not return a
     * usable value.
     *
     * In some rare circumstances, this ID may change.  In particular, if the device is factory reset a new device ID
     * may be generated.  In addition, if a user upgrades their phone from certain buggy implementations of Android 2.2
     * to a newer, non-buggy version of Android, the device ID may change.  Or, if a user uninstalls your app on
     * a device that has neither a proper Android ID nor a Device ID, this ID may change on reinstallation.
     *
     * Note that if the code falls back on using TelephonyManager.getDeviceId(), the resulting ID will NOT
     * change after a factory reset.  Something to be aware of.
     *
     * Works around a bug in Android 2.2 for many devices when using ANDROID_ID directly.
     *
     * @see http://code.google.com/p/android/issues/detail?id=10603
     *
     * @return a UUID that may be used to uniquely identify your device for most purposes.
     */
    public UUID getDeviceUuid() {
        return uuid;
    }

Answer 6

Unique device ID of Android OS Device as String.

String deviceId;
    final TelephonyManager mTelephony = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        if (mTelephony.getDeviceId() != null){
            deviceId = mTelephony.getDeviceId(); 
         }
        else{
            deviceId = Secure.getString(getApplicationContext().getContentResolver(),   Secure.ANDROID_ID); 
         }

but I strngly recommend this method suggested by Google::

Identifying App Installations