AT&T HTC One Android smartphone can be updated to Android 4.3 Slim Beam custom ROM. You can update your AT&T HTC One Android Smartphone to Android 4.3 custom which is developed by Slim Beam. Slim Beam Beta 1 Firmware for Android 4.3 Jelly Bean costume ROM is now available for download. In this post I guide you how to update your AT&T HTC One Smartphone to Android 4.3 Guide ROM easily. Just follow the step by step guide give below. This is not a Official ROM, it is a custom ROM which require a custom recovery like Clockworkmod.



The process is simple to follow, but you may end up as zero or negative results as well. So follow it at your own risk. We shall not be responsible for any damage that this tutorial may cause to your AT&T HTC One.


  • · Charge the battery to at least 60 percent mark. The only step into the process.
  • · Take the backup of entire data. This would prove helpful if your data gets wiped out because due to the process.
  • · Download and install the drivers for your AT&T HTC One to your PC.
  • · Enable USB Debugging Mode in your smartphone. Proceed as Settings > Applications > Development > USB debugging.
  • · This guide is only for AT&T HTC One It will not work on any other variant of AT&T HTC One. So better proceed ahead only if you have this particular variant.

Process to Update AT&T HTC One to Slim Beam Android 4.3 ROM Jellybean Custom Firmware

  • First of all, download the Slim Beam Android 4.3 Jellybean custom firmware for your AT&T HTC One from here.
  • You can download the pack of Google Apps from here.
  • Transfer these zip files to the internal SD of your AT&T HTC One.
  • Now we need to start the device in Recovery Mode. For this, first of all, start your AT&T HTC One by pressing the Volume Up, Menu and Power buttons together.
  • While in the Recovery Mode, look for the option reading Flash zip from SD cardTap on it and then on Choose zip from SD card.
  • Here you need to locate the firmware zip file. Do it!
  • Confirm your selection so as to start the installation of this new custom firmware.
  • The installation will be done in few minutes.
  • Install the Google Apps now. Yeah, follow the same procedure. Simple!
  • When you are done with the installation of both the firmware and Google Apps, just tap on Go BackThen tap on Reboot System Now.
  • Your AT&T HTC One will now restart.

That’s it. You have successfully updated your AT&T HTC One to Slim Beam Android 4.3 Custom ROM Firmware. Have fun