How to Unlock Bootloader on Asus Zenfone 4 Pro ZS551KL – UNLOCK APK

In this article, I will demonstrate how to unlock the bootloader on Asus Zenfone 4 Pro ZS551KL smartphone. So, the company will launch this mid-range smartphone and we are one of the early websites to demonstrate this. Now, let us directly jump to step by step guide on how to unlock the bootloader.


About Asus Zenfone 4 Pro

Here are some of the key features and specifications of the newly launched Asus Zenfone 4 Pro smartphone.

  • Firstly, it has 5.5 inches AMOLED display with a resolution of 1080 by 1920 pixels. A total of 401 pixels per inch.
  • And Asus Zenfone 4 Pro also comes with Android 7.1.1 Nougat.
  • And under the hood, Asus Zenfone 4 Pro has a Snapdragon 845 chipset.
  • The Phone also comes with 6GB Ram and 128GB/64GB Storage. 
  • Furthermore, the camera sensor on Asus Zenfone 4 Pro- 12MP + 16MP dual rear camera and 8MP front shooter.
  • Finally, the battery on Asus Zenfone 4 Pro is a non-removable 3600 mAh.

Also, Read – Various Issues on the phone & How to Fix Them. Tips & Tricks

What is Unlock Bootloader? Unlocking bootloader on Asus Zenfone 4 Pro?

Unlocking Bootloader on the Asus Zenfone 4 Pro smartphone means accessing the way for installing custom recoveries such as TWRP or CWM recovery. Also, rooting your device and installing custom ROMS. Many manufacturers provide smartphones with a locked bootloader and as a result, one need to unlock it before proceeding.  So, Unlocking bootloader is the first step before one can further customize their smartphone.


What are the Pro’s or Advantages of Unlocking Bootloader on Asus Zenfone 4 Pro?

Here are some benefits of unlocking the bootloader on the Asus Zenfone 4 Pro:

  • Firstly, one can root the smartphone after unlocking the bootloader.
  • And you can install TWRP or CWM Recovery on the phone.
  • Also, you will be able to install various custom Roms on the phone.
  • Finally, if you unlock the bootloader on your Asus Zenfone 4 Pro smartphone, the warranty will be void.

Related Article. Root this phone.

How to Unlock Bootloader on Asus Zenfone 4 Pro?

Let’s unlock the bootloader on the Asus Zenfone 4 Pro:

Unlock Bootloader Asus Zenfone 4 Pro

  • First of all, charge the phone fully.
  • Next, enable USB Debugging on Asus Zenfone 4 Pro by going to Setting>About>Software>Build Number and Tap on build number repeatedly so that the Developer mode will turn on.
  • And then go back and click on Developer options.
  • In the developer options, there is OEM unlock option then enable that option.
  • And then back up your current data, unlocking bootloader will wipe all your phone data.
  • Also, allow Installation from unknown sources. And to do that go to Asus Zenfone 4 Pro setting > Security > Device Administrators > Enable Unknown Sources.
  • Now download the unlock tool. To download Asus Zenfone 4 Pro unlock tool, go to Google Search and Type “Asus Zenfone Drivers and Tools”. Direct LINK
  • And click on the first link from ASUS official website. Scroll down & Select OS > Android. 
  • Also, you will find various drivers and software on the page. Look for Unlock Tool and download it on your PC. 
  • And now transfer the APK file to the Asus Zenfone 4 Pro via USB cable. 
  • Next, go to file manager and tap on download folder, look for the APK file and install the Unlock app.
  • Now open the app and agree to the warning popup. 
  • Finally, tap on “Press To Unlock Your Device”.
  • And now the phone will reboot wiping all your mobile data.  
  • Finally, you have successfully unlocked the bootloader on the Asus Zenfone 4 Pro.

Related. Install Custom ROM on this phone. 

In conclusion, Android versions later than lollipop come with an option of OEM Unlock in the developer options. So, its quite easy to unlock the bootloader on any latest smartphone devices. And Still, some of the smartphones may not come with this option. Hence, in order to unlock the bootloader, you need to manually do it via PC.

Related article. Unroot this phone and go back to stock ROM.

If you are encountering any issues regarding bootloader unlocking on Asus Zenfone 4 Pro then do let me know in the comment section below. Furthermore, I will be happy to assist you 😀