Here is a new firmware update that’s been rolling out for the OnePlus One which will take the device to build version YOG4PAS2QL based on Cyanogen OS 12.1. This isn’t a big update, but an incremental release consisting of some crucial updates. The update weighs 18MB and as per the update description in the Cyanogen Update Tracker, it’s a maintenance release that provides some bug fixes and critical security updates.

According to one of the users on the OnePlus Forums, the incremental update brings significant improvements in battery drain. The update is rolling out regionally and may take a while to reach your device. For those who cannot wait for the update any longer, can manually install the latest Cyanogen OS build from the download section. The full ROM and fastboot update files will be available soon on the provided links. So stay tuned.

We have listed manual method to install the OTA on stock firmware. For those who have rooted their device, may proceed with the second method that involves TWRP recovery.

Download Section


OnePlus One Cyanogen OS 12.1 fastboot file:

How to Update Cyanogen OS 12.1 with Stock Recovery

  1. Make sure you already have YOG4PAS1N0 update on Cyanogen OS 12.1.
  2. Download the latest Cyanogen OS 12.1 OTA zip file from the Download Section.
  3. Transfer the OTA zip file in your phone’s internal storage.
  4. Now, you need to boot your OnePlus 2 into Recovery Mode. To know more on how to boot into Recovery, refer Step 3 in the method below or get to this link.
  5. Once your phone boots into Recovery Mode, Select Apply Updates and navigate to the OTA file you just saved on your phone. Select storage 0 if prompted.
  6. The installation process will start on your OnePlus 2 and take a few minutes.
  7. Once the installation is successful, it will automatically reboot. Otherwise, go back and reboot system

If you have a rooted OnePlus One, then you can flash the full ROM through TWRP. However, this process may remove all your previous apps, data and system except for the internal storage. So a backup or nandroid backup is highly recommended.

Install Cyanogen OS 12.1 Full ROM with TWRP Recovery

  1. Download the required ROM (full ROM) file for your device from the download section.
  2. Now transfer the ROM into your device’s internal storage. Place the file where you can easily locate it.
  3. Now reboot into TWRP. To boot into TWRP, power off your phone and press and hold volume down button and power button at the same time.
  4. It is highly recommended that you perform a nandroid backup. To backup your ROM, tap on the backup option and select the following elements: System, Data, Boot, Recovery, EFS and swipe the confirmation action to backup.
  5. You can skip this step, but if after the installation system doesn’t boot, try this step. After performing the ROM backup, return to the TWRP main menu and tap the Wipe button and select Advanced Wipe. Then wipe Dalvik Cache, System, and Cache. (If after the complete process system does not boot, try wiping the Data as well. But its will remove all your data)
  6. Go back to the TWRP main menu again and tap on Install option. Navigate to the ROM file and select it.
  7. Swipe the confirmation button to proceed with the installation. The ROM will be installed.
  8. Once installed, reboot to system.

Once you boot into the system, you can now enjoy the latest Cyanogen OS on your OnePlus One device. If the system does not boot, you can restore the backup ROM from TWRP.

To see how to install OTA using fastboot method, refer to Method 2 this page. Alternatively, you can get the OTA update and install it using the Cyanogen Update Tracker Android app. However, the update is running slow and not all have received the update. You can check and download the OTA update with the app given below.

Cyanogen Update Tracker Price: Free

Also See:

How to Install Oxygen OS 2.1.1 on OnePlus 2

For queries, comment down below. If we have helped you, then like and share us on social platforms. If you need help with other devices, let us know.


  1. Hi Sarang, i am unable to flash the Incremental Update Zip that you mentioned above using TWRP . Moreover , using the Bacon Root Toolkit , i booted phone into Temporary Stock Recovery and flashing the zip failed there too.

    I want to know whether you flashed the Incremental Zip (18 MB) while you had Custom Recovery or Stock Recovery.

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