Update Galaxy S3 to Android 5.0 Lollipop CM 12. After Android 5.0 Lollipop OS was out, different custom ROMs based on this OS were developed for various smartphones and tablets. These ROMs can’t be used on a daily basis as they are not stable. But if you are interested in trying the latest features and looks included in this latest OS then you should definitely try flashing them. Custom ROMs are mostly useful especially for those devices who will never get this Lollipop update ever.

Due to great efforts of some recognized developers like JustArchi and Arter97, Android 5.0 Lollipop which is the latest flavor of Google’s operating system can now be easily installed on your Samsung Galaxy S3 i9300 Smart phone. The Galaxy S3 i9300 launched in 2012 was undoubtedly considered as the best phone Samsung has ever created. Although its specs and features are nothing compared to today’s smartphones, still it was one of the fastest smartphones back when it was launched. This phone was purchased by millions of users in a single month. Because of this, Galaxy S3 has a huge fan base with millions of people still using the phone. Some of its specs include Quad-core 1.4 GHz Cortex-A9 processor, Super AMOLED capacitive touchscreen with 720 x 1280 pixels resolution, Exynos 4412 Quad chipset, 8 megapixel camera, 1.9 megapixel front facing camera and 1 GB RAM. It was launched with Android 4.0.4 Ice cream sandwich which can be further upgraded to Android 4.3 Jelly Bean.

Galaxy S3 i9300 Android 5.0 CM 12 ROM screenshot 1

Due to such good specs the latest Android Lollipop can be easily compatible with it. Today in this guide we’ll be discussing the detailed step by step procedure on how to install Android 5.0 Lollipop based Cyanogenmod 12 custom ROM on your Samsung Galaxy S3 i9300. Cyanogenmod is one of the most popular ROMs out there and if you want to feel and experience the latest Lollipop flavor on your Galaxy S3 then CM 12 is the only ROM for you. It is stable, fast and even improves the overall performance and the battery life. Also if you find any sort of bugs or issues no worries as Cyanogenmod ROMs gets updated often. All the working features are listed below. Have a look.

Galaxy S3 i9300 Android 5.0 CM 12 ROM screenshot 2

Working List:
  • Updater-script (flashing)
  • Bluetooth
  • HW Composer and MALI R4P0 drivers
  • Rotation
  • All sensors
  • Internal and External SD Card
  • Camera
  • Vibration
  • Booting kernel
  • GPS
  • NFC (Android Beam)
  • WiFi
  • MALI blobs (GPU rendering)
  • Open GL (CPU rendering)

Note that this build of CM 12 is in its early stage hence not much stable and may contain few bugs or issues. Still if you want to experience the latest Android 5.0 Lollipop OS on your Samsung Galaxy S3 then follow the further given steps properly.


Try this at your own risk. Neither we nor the developers are responsible for any of the damage caused to your device after following this procedure. Don’t even think if you’re not familiar with this stuff. Although it is very rare that your Galaxy S3 will get bricked or damaged but still we strongly recommend you to follow all the instructions properly as they are mentioned below.


This Android 5.0 Lollipop based Cyanogenmod 12 custom ROM is compatible only and only with Samsung Galaxy S3 with model number GT-i9300. So do not try to flash it if you’re having another device except the one mentioned as it may brick or damage your phone permanently. You must check your device’s model number in Menu->Settings –> About Phone.

  • Make sure that your device is charged at least up to 80% so that it won’t get turn off during the flashing process.
  • Also we highly recommend you to backup all your phone data and settings including contacts, SMS/MMS and call logs etc. to external memory card since it gets wiped in the last step of procedure.
  • Backup EFS present in your phones system directory. This folder contains all your phones specific information such as the IMEI, wireless devices MAC addresses, product code, and much more. So a backup of this folder is essential. There is always a risk that this EFS folder might get corrupted. If so happened, your device will be completely useless & will no longer be recognized by your carrier. Refer our article to backup and restore EFS/IMEI data:
  1. How to backup and restore EFS/IMEI on Android Phones.
  • Make sure you have installed mobile specific drivers on your PC. This is recommended so as to recognize your Galaxy S2 i9100G when connected via USB cable. You can install them by installing Samsung Kies or manually install them from the link given below:
  1. Download latest Samsung USB Drivers.
  • Also ensure that your Galaxy S3 i9300 is rooted.
  • A custom recovery like Clockworkmod (CWM) or TWRP must be installed before proceeding further. If you haven’t installed yet, don’t worry just follow these steps given below:

Step 1: Firstly download this CWM recovery on your PC.

Step 2: Also download this Odin 3-v3.o9 software on your PC and launch it.

Step 3: Now boot the phone into downloading mode. For doing so, firstly switch off your Galaxy s3 completely. Now press and hold ‘Home Button (middle button) + Volume down key + Power Button’ simultaneously until a warning message appears. Now leave all the three keys and just press Volume up button to enter download mode.

Step 4: Using USB cable connect your Galaxy S3 i9300 to PC.

Step 5: As soon as you connect it, the ID:COM section in ODIN will turn blue. Also an Added message will appear in the message window. This will confirm that your device has been successfully connected to the PC.

Galaxy s3 i9300 CWM Odin Screenshot 1

Step 6: Next tick the Auto Reboot option and F.Reset option located on the Odin window. Do not tick or un-tick any other option.

Galaxy s3 i9300 CWM Odin Screenshot 2

Step 7: Then tick against ‘AP’ button and navigate to the CWM recovery package & select it.

Galaxy s3 i9300 CWM Odin Screenshot 3

Step 8: Initiate the process by pressing on the Start button located on the Odin window.

Galaxy s3 i9300 CWM Odin Screenshot 4

Step 9: Be patient until the process completes fully. As soon as it completes successfully, you’ll see that the ID:COM section on the Odin window is turned green with the message ‘Pass’ below it. This will confirm that you have properly flashed the CWM recovery on your Galaxy S3 i9300. To confirm this switch off your phone and then press ‘Home Button (middle button) + Volume up key + Power Button’ simultaneously until you land into CWM recovery.

Now lets proceed to the actual Android Lollipop flashing process.

Galaxy S3 i9300 Android 5.0 CM 12 ROM

Procedure to install Android 5.0 Lollipop on Galaxy S3 i9300 [CM 12]:


  1. Download Cyanogenmod 12 Custom ROM for Samsung Galaxy S3 i9300.
  1. Download arter97 kernel.
  1. Download Google Apps (Android 5.0 Lollipop).


Step 1: Download all the zip package files in a specific folder on your PC. Remember not to extract them.

Step 2: Use USB cable and connect your Galaxy S3 i9300 to your PC. Enable USB debugging mode and copy the downloaded files on your phones SD card.

Step 3: After copying, safely disconnect your phone from PC & switch it off completely. Now boot your phone into CWM recovery mode now. To do so, press and hold Volume up + Home button (middle button) + Power button together till you enter recovery mode.

Note: Touch won’t work in recovery mode. So use Volume keys for navigating up and down and use Home button for selection.

After you land into recovery mode, make a complete backup of the ROM which you are currently using. Such a backup is also called as Nandroid backup. So basically the nandroid backup is the backup of your phones entire operating system & is always helpful during the failure while flashing process or during any problem with the ROM, then you can easily restore your saved previous ROM.

Refer our detailed article for taking Nandroid backup:

  1. How to take Nandroid Backup of any Android Phone with 8 simple methods.

Step 4: For taking a complete nandroid backup of your current ROM, use Volume keys and navigate to the ‘backup & restore’ option on the recovery mode itself and on the next screen select ‘backup’ option using Home button. This will make a complete nandroid backup of your current ROM. It will be saved on your SD card. Refer screenshots.

Nandroid backup screenshot 1Nandroid backup screenshot 2

Step 5: Next you need to wipe the data and cache partitions from your phones internal memory. For doing so, use Volume keys and navigate to the ‘wipe data/factory reset’ option present on the recovery mode. Select it using Home button. On the next screen press Yes option to start the wiping process. Similarly navigate to the ‘wipe cache partition’ option on the recovery mode and select it to wipe the caches. Note that this step will clear all the data & caches from your phone thus a complete backup of everything must be done before attempting this step (Refer Pre-requisites section).

CWM wipe data cache screenshot

Step 6: After wiping everything, select the Advanced option located on the recovery mode itself. On the next page select Reboot Recovery  option.

reboot recovery screenshot

Wait until you boot again into recovery.

Let’s move to the actual Android 5.0 Lollipop based CM 12 ROM flashing process.

Step 7: On the main screen of the recovery you’ll find the ‘install zip from SD card’ option. Select it using Home button. Then on the next screen select ‘choose zip from SD card’ option. This will show all the files and folders present on your external SD card. Just select the Android 5.0 Lollipop based Cyanogenmod 12 ROM which you’ve just copied earlier and select it using Home button. On the next page select ‘Yes’ option to initiate the actual Android 5.0 Lollipop ROM flashing process. Wait for some time to complete it successfully.

CWM recovery Screenshot

Step 8: Similarly flash the arter97 kernel file.

Step 9: After the process completes, press back button to return to the main menu. Again select ‘wipe data/factory reset’ option and ‘wipe cache partition’ option as you did before to clear all your phones data & cache. This step is essential to solve the boot loop issue.

Step 10: Similarly flash the Google Apps (GApps) as you’ve flashed this Cyanogenmod 12 custom ROM. Just remember not to wipe data/cache after flashing them.

Step 11: You may now restart your Galaxy S3 i9300 by selecting ‘reboot system now’ option from the recovery mode. This first boot will take more time to start than usual. But don’t panic after a couple of boots it’ll be normal.

reboot system screenshot

Note: If you want to restore back your previous Rom, then you can do that by going back to the recovery mode by pressing & holding Home Button (middle button) +  Power Button simultaneously and select ‘Backup and Restore’ option and then on next page select ‘Restore’ option. Select the ROM you want to restore.

If you face any 2G/3G network related issues from this CM 12 ROM then just flash this ril.zip file from the recovery.


Yoyo! The latest Android 5.0 Lollipop based Cyanogenmod 12 Custom ROM has been successfully flashed on your Samsung Galaxy S3 GT-i9300 smartphone. Go to Menu->Settings->About Phone and confirm it. Enjoy the all new features and customization on your device after flashing this ROM. Also don’t forget to share your experience of this ROM with us. If you face any kind of difficulty while going through the procedure or have any issue after flashing this ROM then feel free to text us through the comments section below. I’ll try to provide you with an exact solution. Enjoy! 🙂

Also Read: How to Fix Google Play Store Errors in any Android phone.

Also Read: How to Increase Internal Memory of any Android Smart Phone.

Also Read: How to Crack Unlock Pattern/Password/Pin lock of any Android Smart Phone.