Sony Xperia Z3 Marshmallow ROM available for download, experimental build at best

Sony Xperia Z3 users ready to jump to gun for Marshmallow update may like the idea of an AOSP ROM that boots and run fine, but because it doesn’t have cellular connectivity yet (thus calls, messages, etc don’t work), it’s not a good ROM for you if you are looking to use it as daily driver.

But if bragging is what you want, then you can give this Xperia Z3 Marshmallow ROM a try.

We have our eyes set on Further development of the project, and once a good build comes out, we will be sure to share that with you guys right here. Be sure to check this page often.


As of Oct 16, 2015:

  • SIM not working so no mobile data, calls or sms
  • Auto rotation
  • Minor Graphic glitches
  • Some force closes in apps
  • Sound
  • Camera
  • Others


Supported devices

  • Xperia Z3
  • Don’t try this on any other device than the one specified above.

Use the Droid Info app, to determine the codename of your Xperia Z3. If it is the one specified above, then it should be compatible with the 6.0 custom ROM we have here.


Warranty may be void of your device if you follow the procedures given on this page. You only are responsible for your device. We won’t be liable if any damage occurs to your device and/or its components.


Backup important files stored on your device before proceeding with the steps below, so that in case something goes wrong you’ll have backup of all your important files.

How to Install

Required: You Make sure your device’s bootloader is unlocked. For help, see this page. Also, make sure that you have TWRP recovery installed, because it will be needed to install Google Apps (Gapps), that aren’t included in 6.0 ROM by default. No need of TWRP for installing 6.0 ROM, btw.

Step 1. Download the Marshmallow ROM files from above. That is, system.img, userdata.img and boot.img. And also the Gapps file, to install Google Apps after installing the ROM.

Step 2. Create a folder called z3update and transfer the system.img, boot.img and userdata.img to this folder.

Step 3. Connect your Xperia Z3 to PC. Transfer the Gapps file to it. Remember the file’s location. And disconnect the device from PC now.

Step 4. Boot your Xperia Z3 into bootloader mode. If you are rooted, you can use Quick Boot app from play store. To manually boot into bootloader mode, do this:

  • Power off the device. Wait for 4-5 seconds after screen goes off.
  • Press and hold Volume Up button and then connect the device to PC using USB cable. You will enter fastboot mode. Screen won’t show fastboot written on it, btw.

Step 5. Now, open command window in the z3update folder, in which you have the system.img file with other two files. For this:

  1. Open that z3update folder and then left click on empty white space in the folder.
  2. Now, while holding shift key, right click on empty white space to get a pop-up as shown below.
  3. Now choose Open command window here option from that.

open command windows here
You will see a command window open up, with location directed to z3update folder.

Step 6. Run the following commands to install the Marshmallow update on Xperia Z3.

fastboot flash boot boot.img
fastboot flash system system.img
fastboot flash userdata userdata.img
fastboot reboot

Wait for Xperia Z3 to finish booting up, it may take some time. Once it does, check the Settings > About device. You should have Marshmallow under Android version. Congos!

→ Btw, if you face force close on apps a lot, or device lagging too much, then do a factory reset using TWRP recovery to solve that problem.

Step 7. You don’t have Google Apps right now. You need to flash the Gapps file from recovery mode. Make sure you have TWRP installed, and have transferred the Gapps file to your Xperia Z3 too.

  1. Boot your Xperia Z3 into recovery mode. If you are rooted, you can use Quick Boot app from play store.
  2. [Optional] Once in TWRP, create a backup of your device. Tap on Backup, and then select all the partitions for back. Now do the swipe action at bottom to start creating a backup for emergency cases. This backup is really a lifesaver!
  3. Now, install the Gapps file. On TWRP’s homescreen, tap on Install, and then locate the Gapps file and tap on it. Then do the Swipe action at bottom to begin flashing the update.
  4. When it’s done, tap on Reboot system button to restart the device.

That’s it.

Let us know if you need any help with this, via comments below.

Via CedArctic

Posted by
Kapil Malani

A die-hard Liverpool FC fan, Kapil is a big fan of Batman, Android and street Cricket. In that order, probably. Email: [email protected]