How to install Android 6.0.1 Marshmallow on Galaxy S3 i9300 via SlimROM

If you are a Galaxy S3 GT-i9300 owner and looking for a perfect Android 6.0.1 Marshmallow ROM? Then you are at the right place, we are here at to provide you the best custom ROMs for your device. In this guide we have brought Android 6.0.1 Marshmallow ROM for old Galaxy S3 i9300 to give it a younger look with latest features. The supported modern devices are already getting stock Marshmallow firmware even latest Nexus flagships are on Android N but in this situation the Galaxy S3 i9300 is a bit old to taste the latest firmware.

But now it’s possible to install Android 6.0.1 Marshmallow on Galaxy S3, credit goes to SlimROM, If you think you are good enough to perform such operation with your device then what are you waiting for? Just go ahead and follow the below description. In the previous articles we have mentioned the similar procedure for other devices now in this guide following the same process we will install Android 6.0.1 Marshmallow on Galaxy S3 i9300 via SlimROM.

How to install Android 6.0.1 Marshmallow on Galaxy S3 i9300 via SlimROM

Disclaimer: This guide includes flashing custom ROM on your device, it is not an official firmware but will flash the custom firmware. The writer is not responsible for any damage happens to your device during the whole operation neither we are forcing you to perform such operation.

Before you begin:

Installing custom ROM on your device needs some early preparations to be made and these preparations include;

A custom recovery is the most necessary element while installing custom ROMs or any .zip file in your device so a custom recovery like ClockworkMod or TWRP must be installed on your device. Visit our custom recovery section to download custom recovery for your device.

Keep your battery charged or at least your device should contain at least 80% charge before the flashing operation.

Android USB drivers for your device should be installed on your PC, or you can download USB drivers for Samsung

If the PC is unable to unable to detect your device after even after installing Android USB drivers for your device, then you need to perform one more step, Enable USB debugging.

To enable USB debugging in your device go to Setting >> Developer options >> USB debugging.

Sometimes “Developer options” are not visible in device settings menu, so what you need to do is, go to Settings >> About device >> Software information and there you will see an option build number. Tap it 7 times until a pop up arises with a message that you are now a developer, that’s it now go back and the Developers option is visible in the settings menu.

Create a Backup of your complete Android device

Backup is the most necessary part for your device you need to create a Nandroid backup of your device through custom recovery. We prefer Nandroid backup over other many apps because you don’t need to download multiple backup apps for specific purpose, the Nandroid backup will let you create backup of your device including; Messages, call log, settings and calendar including whole Android OS. Click the below link to create a Nandroid backup.

How to create a Nandroid backup/restore of your Android device

You can easily restore your backup when ever you wish to do so, this is good in aspect if your device accidentally met some issue during the flashing process.

Once you done with the above preparations now it’s time to flash Android 6.0 Marshmallow on your Galaxy S3 i9300. Just go ahead and follow the steps in sequence to avoid any issue while flashing Android 6.0 Marshmallow on Galaxy S3 i9300.

Process to install Android 6.0.1 Marshmallow on Galaxy S3 i9300 with SlimROM


Once you successfully downloaded the Android 6.0.1 Marshmallow SlimROM zip and gapps on PC, Now connect your device to PC and move the downloaded files on the internal storage of your device. [If you downloaded it via phone then skip this step]

Its time to reboot your device into recovery Mode, to do so you can search for it or use hardware buttons combination. (If your device is rooted then its super easy, just visit Google Play and download any third party reboot app for this purpose)

Once your device successfully boots into recovery mode, select the downloaded Android 6.0.1 file and confirm it by swiping the slider for (TWRP) or yes for (CWM).

Now repeat the above step for the installation of Google Apps.

Once successfully done with the installation procedure simply reboot your device, please note the first boot up may take 5 to 7 minutes so be patient as things needs to be settled up for boot.


Download Android 6.0.1 SlimROM Marshmallow ROM for Galaxy S3 i9300

Download Google Apps [Gapps]

That’s it! Congratulation you have successfully installed Android 6.0.1 Marshmallow via SlimROM on Galaxy S3 i9300. Follow us on Facebook/Twitter/Google+.

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