Update Galaxy S3 I9300 to Android 5.1 Lollipop with CyanogenMod (CM12.1) ROM

Galaxy S3 has been great success and keeping this fact in mind, the developers are not giving up on this ex Samsung flagship. So the CyanogenMod team has decided to tweak their ROM to make it compatible with S3 and today they have released CM12.1 based on Android 5.1 Lollipop for Galaxy S3 I9300 phone.

Android 5.1 Lollipop S3 I9300

If you happen to own this phone and want to give it Lollipop taste, then this is the best time and ROM to use and if you have made your mind then start going through the tutorial we have put together just for your convenience. The tutorial will help you to smoothly install CM12.1 Android 5.1 Lollipop custom ROM on your Samsung Galaxy S3 I9300 phone, so keep and update.

This ROM is only for Galaxy S3 I9300  and practicing it on any other device can be fatal for that device. [Verify your phone model from Settings –> About Phone]

Safety Guidelines

  • Make sure your Galaxy S3 I9300 is at least 66% or charged.
  • Ensure that you have complete backup of all your important data.
  • Make sure USB debugging is enabled on your smartphone. [If not, enable from Setting –> Developer Options]
  • Download Samsung USB Drivers and install them on your computer.

Files Required

The CM12.1 ROM mentioned in this post belong to its respective developer. We are just covering tutorial to help you in its installation which is well-written and very easy to understand. However if you damage or brick your phone, AndroidsDNA.com cannot be held responsible.

How to Update Galaxy S3 I9300 to Android 5.1 Lollipop with CyanogenMod

Step 1: Download the custom ROM and GAPPS. For easy browsing, place both the downloaded zip files on desktop of your Computer.

Step 2: Connect your Galaxy S3 I9300 to your computer to transfer the download zip files to your phone SD card. [Make sure latest Samsung drivers are installed, otherwise your PC won’t recognize your phone]

Step 3: Turn Off your phone and boot it to recovery mode. [You can’t use touch in recovery mode, so use Volume Up and Down buttons for navigation and Power button for selection]

Step 4: In recovery mode, first tap on “wipe data factory reset” option to perform a factory reset. Once this is completed, go to advanced options and select “wipe the cache” followed by “dalvik cache” options to clear the cache.

Step 5: Go back to main recovery menu and select “Install zip from sd card” followed by “choose zip from SD card” and select the ROM zip file you have transferred to SD card in Step 1. Once ROM flashing is completed, repeat the same step for GAPPS.

Step 6: Repeat the above step for Google Apps (GAPPS) installation.

Step 7: Once the installation is completed, go back to main recovery menu by selecting “+++++Go Back+++++” option  and reboot your phone by choosing “reboot system now” option from main menu. For the first time, your phone might take little more time than it usually takes, so don’t be panic as it is normal and will be only for 1st time.

Let us know your journey of updating your Galaxy S3 to Lollipop via CM12.1 custom ROM.


  1. Aswin says

    Installed,but there is no in call interface in any of the updates..i am not able to answer the calls.(In CM 12)

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