Looking to update Galaxy S4 I337 to Android 6 Marshmallow? OctOS custom firmware based on Android 6.0.1 Marshmallow is now available for the smatphone. Bringing tons of custom features and tweaks, this ROM is a weekly firmware, so there might be still be some bugs. While this is a weekly build, you might want to try the ROM as not many Marshmallow based ROMs have been released for Samsung Galaxy S4 I337. Following these steps you will be able to update Samsung Galaxy S4 model I337 to Android 6.0.1 Marshmallow.

- Some of the best Android 6 Marshmallow custom ROMs

Remember, this is NOT an official Android 6.0.1 Marshmallow release from AT&T. This means that flashing the custom firmware will void your device's warranty.

Before you update Galaxy S4 I337 to Android 6.0.1:

• Backup any important data from your Samsung Galaxy S4 SGH-i337 as a complete wipe will be required during the flashing process.
• Enable USB debugging option on your device: Settings > Development Options > USB debugging.
• Samsung Galaxy S4 I337 must be rooted, unlocked and installed with a recovery tool like TWRP or CWM.
• Your device must be charged to at least 60% of power.

Note: this tutorial is focused on AT&T Samsung Galaxy S4 I337; kindly do not try this guide on other Android & Samsung devices.

Update Galaxy S4 I337 to Android 6.0.1 OctOS:

Required files:

• Download the OctOS Android 6.0.1 Marshmallow for Galaxy S4

Once you download and save the zip file on your computer, here are the steps to proceed:

• Connect Galaxy S4 to your computer using a USB cable and copy the zip file to your phone’s SD card.
• Disconnect the USB cord and power off your Galaxy S4.

• Boot it into recovery mode by pressing and holding Volume Up + Home + Power buttons together.

• Wipe data task: from CWM recovery menu, select wipe data / factory reset and confirm the process.

• From recovery menu, select install zip from sdcard followed by choose zip from sdcard. Locate the OctOS Android 6.0.1 ROM and confirm the flashing process.
• Return back to main recovery menu and reboot your Galaxy S4 I337 into the new custom ROM. First boot takes a good 5 minutes so please be patient.
• Ta da!

Don't forget to comment if you are happy with this one-of-the-first Marshmallow based ROM for AT&T Galaxy S4.

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