Asus Zenfone 2 ZE551ML Firmware Flash File | Stock ROM Guide

Asus smartphones are quite impressive in terms of the performance and camera department when it comes to the budget segment. However, the company isn’t that active in pushing the latest software updates apart from the security patch updates. That means most of the Asus devices are eligible to receive a maximum of two years of Android OS updates that don’t even stand out consistently. Therefore, plenty of Asus device users either shift to a third-party custom firmware or are stuck with the older generation stock firmware. Now, in both scenarios, users need to flash the stock firmware again to improve the device performance, etc. If you’re an Asus Zenfone 2 ZE551ML device user and want to install the Firmware Flash File | Stock ROM then check out this guide completely.

Due to Android’s open-source project, most of the third-party firmware brings a lot of improvements and features but those aren’t stable enough like the official stock firmware. So, users start getting multiple bugs, app compatibility issues, battery draining, slow charging, OTA update issues, reduced performance, and more. Sometimes unlocking the device bootloader, rooting the system, or installing any module can also cause several issues with your device as a daily driver. Whereas even if you’re using the official stock firmware and there is no software update for your model over the years that means your device will gradually starts lagging, overheating, app crashes, slow performance, etc. That’s why installing the Stock ROM again will help you to fix most of the issues with your older device.

Asus Zenfone 2 ZE551ML Firmware Flash File | Stock ROM Guide

Asus Zenfone 2 ZE551ML Specifications

The Asus Zenfone 2 ZE551ML has a 5.5-inches IPS LCD Full-HD+ display that includes 1080×1920 pixels resolution quality, a 16:9 aspect ratio screen, Corning Gorilla Glass 3 support, etc. It came with Android 5.0 Lollipop out of the box and upgraded to Android 6.0 Marshmallow officially. The handset is equipped with a quad-core Intel Atom Z3580 SoC (4GB RAM model), Intel Atom Z3560 SoC (2GB RAM model), PowerVR G6430 graphics. While it’s paired with a 2GB/16GB, 2GB/32GB, and 4GB/64GB storage variant that also supports a dedicated MicroSD card slot for storage expansion.

The device sports a single 13MP rear camera that offers AF, Dual-LED dual-tone flash, Panorama, HDR mode, etc. There is a 5MP selfie camera (f/2.0) as well. Talking about the connectivity options, it has a 3.5mm audio jack, Wi-Fi 802.11 a/b/g/n/ac, Wi-Fi Direct, Bluetooth 4.0, GPS, A-GPS, GLONASS, NFC, FM Radio, MicroUSB 2.0 port, USB OTG, etc. It has an ambient light sensor, an accelerometer, gyroscope, proximity, compass sensor, etc. The Asus Zenfone 2 ZE551ML is backed by a 3,000mAh battery that supports 18W fast charging.

Advantages of Stock Firmware

  • A Stock ROM can Unbrick the Asus Zenfone 2 ZE551ML
  • Fix the Bootloop issue
  • Upgrade or Downgrade the Android version
  • Remove Root access or modules
  • Fix lags or stutters
  • Fix OTA update issues
  • Gain the device warranty (if available)

Steps to Install Asus Zenfone 2 ZE551ML Firmware Flash File | Stock ROM Guide

Here we’ve shared the firmware download link and other requirements that you should follow before jumping into the firmware installation process.


  • The mentioned stock firmware file is only compatible with the Asus Zenfone 2 ZE551ML.
  • Make sure to charge your device battery at least 50% to avoid occasional shutdowns.
  • A PC/Laptop and a USB cable are required for the firmware flashing.
  • Ensure to take a full device data backup (No Root) before installing the firmware.
  • Grab the latest ASUS USB Drivers for your computer.
  • You’ll require to download ADB Fastboot Drivers (Second Method).

Download Firmware:

  • Download
  • WW- (2017/07/17) – Download [Android 5.0 Lollipop]
  • Download
  • WW- (2017/07/17) – Download [Android 6.0 Marshmallow]

Warning: Keep in mind that taking a full data backup is highly recommended. GetDroidTips won’t be held responsible if anything goes wrong by following this guide. Do it at your own risk.

Method 1 – Install via Recovery:

  1. Download the zip file from the above link and rename the file to and move to device internal storage (/downloads folder).
  2. Now, Switch Off your device and reboot into recovery mode by pressing the Power button + Volume UP button together for a few seconds.
  3. After booting into recovery mode, select apply update from sd card.
  4. Now, choose the file which you have downloaded earlier.
  5. Wait until the installation process completes.
  6. Once the installation process is completed, you can reboot your Zenfone 2 ZE551ML.
  7. Done. you have upgraded your smartphone.

Method 2 – Install via ADB Sideload:

  • First, you need to download the ADB and Fastboot tool for Windows and Mac and extract it on your PC.
  • Now, move the downloaded OTA zip file to the installed ADB Folder.
  • You need to enable USB Debugging on your handset.
  • Go to your PC/Laptop and open the extracted ADB Folder and open Command Prompt by pressing Shift Key + Right Mouse Click.
  • Now, reboot your phone to recovery mode by pressing the Volume UP + Power button together for a few seconds.
  • Connect your mobile to the PC via a USB Cable.
  • Now, enter the following command in the command prompt and hit enter:
adb devices
  • This command will show if any fastboot device is connected. If it doesn’t show, then please check the drivers are installed properly and try again.
  • If your device is listed, then type the command given below and press enter:
adb sideload
  • Wait until the installation process completes.
  • Once the installation process is complete, restart your device.
  • Done. You have successfully upgraded the Asus Zenfone 2 ZE551ML.

We hope that you have successfully installed the Stock ROM on your Asus Zenfone 2 ZE551ML device. Feel free to comment down below for further queries.


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