The Samsung Galaxy S3 is one of the most popular devices to root and because of that it’s also going to be one of the most popular to unroot. Here you can find the guide to unroot Samsung Galaxy S3 GT-I9300 smartphones by flashing the stock ROM. Here’s all you need to do to unroot Samsung Galaxy S3 devices with the model number I9300.

REQUIREMENTS

• The following guide is only made to unroot Samsung Galaxy S3 smartphones with the model number GT-I9300. You can check your model number by navigating to the Menu > Settings > About Device > look at the model number. If you do not see the same model number (I9300), you cannot follow this guide or else you will brick the device.

BEFORE WE BEGIN

• Download the Samsung USB Drivers for mobile phones from our USB Drivers page here. Alternatively, you can head directly to the Samsung website and find it available on the Samsung Developers page.
• Make sure you have the USB Debugging Mode enabled on your device. You can do that by navigating to the Menu > Settings > Developer Options > USB Debugging Mode. Once you have that enabled you are then able to connect your device to the computer and get the job done.
• Flashing the Android stock ROM on your device will unroot the device and restore the warranty. The only exception for that is if your device has Samsung’s Knox security. However, Knox was not out yet when the Samsung Galaxy S3 came out and therefore you will restore the warranty if you have any time left on the warranty agreements.

HOW TO UNROOT SAMSUNG GALAXY S3 GT-I9300

• Download the Samsung Galaxy S3 stock ROM from the Sam Mobile page here.
• Download the latest Odin flashing tool from here.
• Down load both of the files above to the desktop of the computer and extract them.
• Extract the files by right-clicking over the files and choosing the “extract here” option.
• Long-press the Power button until your device turns completely off.
• Reboot the Samsung Galaxy S3 in download mode: Volume Down + Home + Power buttons at the same time.
• Release the three buttons and just press the Volume Up button when your screen tells you to do press it.
• Connect the device to the computer using the USB cable.
• Wait until the ID: COM port changes in the Odin app on the computer and it gives the “added!” message in the message box.
• Click the PDA/AP button and browse the desktop for the stock ROM that unroots your Galaxy S3 smartphone.

Wait until that stock ROM completes installing before unplugging from the computer. You’ll know it’s done when you see the pass message on the display and your device reboots automatically.