Will Resetting Android Remove the Root?

Performing a factory data reset on an Android-based mobile device does not automatically remove the installed root binaries. Therefore, the device should remain fully rooted following the reset, regardless of the specific root method used, such as systemless root strategies like Magisk or legacy system-wide methods such as KingRoot, iRoot, etc.

Why a Factory Data Reset Does Not Remove the Root

The effectiveness of a factory data reset in removing root access on an Android device depends on the type of exploit and methodology used to root the phone. Older methods of system-mode rooting, particularly those seen on devices running Android 5.1.1 and earlier, were not affected by a factory data reset as long as the Superuser (SU) daemon and corresponding binaries were correctly injected into the /system partition. In these scenarios, a factory data reset would only clear the /userdata and /cache directories, leaving the /system partition intact and thus preserving the root access.

Current Methods of Rooting and Their Impact on a Factory Data Reset

Since the release of Android 6.0 and Android 5.1, the situation has changed. With the implementation of security features like Verified Boot (dm-verity) and the advent of the A/B partition index in newer devices like the Google Pixel series, rooting methods have become more complex. A systemless rooting method was introduced to address this challenge, allowing for root access without altering the /system partition. This method, developed by XDA Senior Developer Chainfire, involves flashing a custom root script via a custom recovery environment. Here, the stock boot image is unpacked, patched, and repacked, with the patched image then flashed to the /boot partition. This ensures that the Android OS remains fully rooted without altering the /system partition.

However, the systemless rooting method is not foolproof. As mentioned, it typically will not survive a factory data reset or a manual update of the OS. Thus, after a factory data reset, the device will likely retain the root access, even if the root binaries are wiped. In some cases, the root access might be retained, especially when using certain methods like Magisk starting from versions 16.6 or above.

Methods to Remove Root Access

If you wish to completely remove the root access from your phone, there are a couple of methods you can try:

Unroot via Root Manager: Many root managers, such as SuperSU, offer a built-in unroot function. You can use this to completely remove root access. Flash Stock ROM: A more complex but thorough method is to flash the stock ROM. This involves connecting your device to your PC, opening the ADB (Android Debug Bridge) interface, and following the flashing instructions for the specific device model.

Keep in mind that unrooting the device through the factory data reset process can sometimes remove apps like SuperSU but not the root access itself. In some instances, updating the firmware might unroot the device by replacing all the necessary root binaries.

Conclusion

While a factory data reset on an Android-based device may not necessarily remove the root access, the specific outcome depends on the root method used, the Android version, and the security measures implemented by the device manufacturer. For systemless rooting methods, a factory data reset might wipe the root access, while for older or Magisk system rooting methods, the root access might remain intact or be lost depending on the version of Magisk used.