We don’t know if Samsung will release Android 5.1.1 Lollipop for the Samsung Galaxy S4 devices or not. We also just don’t care because we have this unofficial CM 12.1 custom ROM for Galaxy S4 to taste the sweetness of Android 5.1.1 Lollipop on our Galaxy S4 devices. The CM 12.1 custom ROM for Galaxy S4 LTE GT-I9506 will give you the stock look of Android 5.1.1 Lollipop on your device. Get ready to install it on your phone but first check out the precaution section.

You need a PC with an internet connection because the ROM zip file is big and will take a lot of data to download from the internet so better use a broadband to download it. Also you need a USB cable to connect your phone to your PC and transfer some files. Your phone with custom recovery installed on it.

CyanogenMod Ninja Turtles


  • You should backup all of your important data stored on your phone to your PC or somewhere else where it will be safe.
  • Sync your contacts to your Google account which will keep them safe from any damage.
  • Charge your phone to 70% battery before installing this ROM on your phone.
  • This installation is only for Samsung galaxy S4 LTE A GT I9506 only, do not try it on other devices.


Steps to install CM 12.1 custom ROM to Samsung galaxy S4  GT-I9506:

  1. First download CM 12.1 custom ROM zip file to your PC and save it on desktop so we can easily find it later.
  2. Download Google apps for CM 12.1 custom ROMs from this page and save it to desktop.
  3. Connect your phone to your PC using USB cable and transfer these zip files to your phone and unplug it when it’s done.
  4. Now turn your phone off completely and turn it on by pressing and holding the Power key and Volume Up key for some time till you see Recovery Mode.
  5. In Recovery, first tap on “backup” and confirm to take a backup of earlier ROM, this is important so if anything goes wrong during the installation process, then you will be able to go back to the previous ROM using this backup file.
  6. Now tap on “wipe” and confirm to wipe the internal memory of the device and reset it to factory settings.
  7. Now tap on the “install” option and you will see a window with all the directory of your device. Select the CM 12.1 ROM zip file and confirm to install it on your phone.
  8. After the installation, tap again on the “Install” button and this time select the GApps zip file to install.
  9. Now to come back to OS mode just tap on Reboot then System.

Wait for some time, don’t worry first boot will take some time, this is not unusual. Now when you see welcome screen just fill the details and use your phone as before.