Latest Android 5.1 can now be flashed on Samsung Galaxy S4 model number I9505 using the latest version of the CyanogenMod. CM12.1 Android 5.1 custom firmware brings new features while fixing earlier bugs and problems. Follow thesesteps to update Galaxy S4 I9505 to Android 5.1 CM12.1.

-Also, read: S6 Edge Craze Pushes Samsung to Produce Massive Quantities of Galaxy S7 Display

Prerequisites to update Galaxy S4 i9505 to Android 5.1CM12.1:

Backup any important datafrom your Samsung Galaxy S4 I9505 as a complete wipe will be required during the flashing process.Enable USB debugging option on your device:Settings>DevelopmentOptions>USB debugging.Samsung Galaxy S4 I9505 must berooted, unlocked and installed with a recovery tool likeTWRPorCWM.Your device must be charged to at least 60% of power.

Note:this tutorial is focused on Samsung Galaxy S4 LTE i9505; kindly do not try this guide on otherAndroid&Samsungdevices.

How to update Galaxy S4 i9505 to Android 5.1Lollipop:

Required files: downloadthe CM12.1 Android 5.1 Lollipop custom firmware for Galaxy S4 fromhereand save it on your computer. Do not extract the contents. Also download Google Apps Package.

Connect yourGalaxyS4 to your computer using a USB cable and copy the zip file to your phone’s SD card.Disconnect the USB cord andpower off your Galaxy S4.Boot it into recovery mode: switch the phone on while pressing and holding Volume Up + Home + Power buttonssimultaneously.Perform aNandroid backupof your current OS:Backup>backup and restoreon ClockworkMod recovery.Wipe data task: from CWM recovery menu, selectwipe data / factory resetand confirm the process.From recovery menu, selectinstall zip from sdcardfollowed bychoose zip from sdcard.Locate the CM12.1 Android 5.1 Lollipopcustom firmware and confirm the flashing process.Return back to main recovery menu and reboot yourGalaxyS4 I9505into the new custom ROM. First boot takes a good 5 minutes so please be patient.

Enjoy the latest Lollipop!