Download Sony Xperia 1 II XQ-AT51 Firmware Flash File (Stock ROM)

On this page, we will guide you on how to install the official firmware file on Sony Xperia 1 II XQ-AT51 based on Android 10. The device is powered by Qualcomm...

Abd Razaaq

Last updated on November 24, 2025

Abd Razaaq

Author

I'm a Tech Content Writer and Full-Time blogger. Since I love Android and Google's device, I started my career in writing for Android OS and their features. This led me to start "GetDroidTips". I have completed Master of Business Administration at Mangalore University, Karnataka.

Why We Need Stock Firmware?

A Stock ROM or Firmware is official software crafted and developed by the official manufacturer for a particular device. It will be stable and almost bug-free as well. The Stock ROM comes with necessary system files and applications which provides a better user experience than a custom ROM.

Though a Custom ROM offers customizations and tweaks, it has some security issues possibly. You can’t really rely on a Custom ROM as compared to the Stock ROM. Whereas, you can also fix some of the device issues as well.

Advantages of Stock ROM:

Here are the answers to why you need to download and save the Sony Xperia 1 II Stock ROM flash file on your computer.

If your device is dead, you can unbrick using the Stock ROM file
You can fix or repair the IMEI on your device using DB files from Stock ROM
Remove any malware or Adwares from Sony Xperia 1 II
You can fix the boot loop issue on Sony Xperia 1 II
Fix Unfortunately, the app has stopped error on Sony Xperia 1 II
Fix Network related issue
Patch Boot image to Root using Magisk
You can unroot Sony Xperia 1 II
To Reset or Remove FRP on your device
Restore Sony Xperia 1 II back to Factory State

Firmware Details:

Device Name: Sony Xperia 1 II XQ-AT51
ROM Type: Firmware
Gapps File: Included
Tool Supported: Xperia Flash Tool
Processor: Qualcomm Snapdragon 865 5G
Android Version: Android 11

How to Flash Sony Xperia 1 II XQ-AT51 Firmware File

Before installing the Stock ROM on your Sony Xperia 1 II XQ-AT51, you should download the firmware flash file. Then download and install the USB Drivers and flash tool on the PC as well. Once you’re done with these, you can proceed to the steps below. But let’s take a quick look at the Stock Firmware importance and firmware details below.

Pre-Requirements:

Before following this guide, make sure that you have enough battery backup on your device (at least 50% or higher)
To begin with, you will have to enable OEM Unlocking. For that, head over to Settings > About Phone > Tap on Build Number 7 times > Go back to Settings > System > Advanced > Developer Options and Enable OEM Unlocking.
Next up, download and install the XperiFirm Tool on your PC.
Also, download and install the NewFlasher Tool on your PC.
We would recommend you take a complete device backup and make sure that it is sufficiently charged as well.
Finally, download and install the Sony USB Drivers on your PC.

That’s it. These were all the required files. You may now proceed with the steps to flash the Sony Xperia 1 II XQ-AT51 firmware file.

Download Flash Files

Software Details	Download Link
Flash File Name: 58.1.A.5.280 File Size: 2.4 GB Android Version: 11.0	Download XperiFirm Tool

STEP 1: Download Firmware

To begin with, you will have to download the firmware for your XQ-AT51 with the desired region. For that, launch the XperiFirm software on your PC
Next, select your device (Sony Xperia 1 II) from the left-hand menu bar and select the model number XQ-AT51.
Go through the firmware information section and select the region.
Then on the right side, click on the latest available firmware that it displays. It should be present just beneath the Available Firmware section.
A popup dialog box will then appear, click on the Download button.

The downloading process will now begin and once that is done, you will get an Unpacked Successful message. Click on OK. You could also go through our guide on how to install stock firmware on Sony Xperia using Xperifirm and Flashtool to gain more knowledge about this tool.

If you have flashed the firmware using this guide, then you don’t have to follow the second and the third step. If not, you can flash the firmware using the Newflasher tool command.

STEP 2: Boot your Sony Device to Flash Mode

You will now have to boot the device to Flash mode. To do so, power off your device. Then press and hold the Volume Down key and connect your device to the PC via the USB cable.
As soon as the Notification LED light turns green (while the device is in a switched-off state), it indicates that the device has been successfully booted to Flash Mode.

STEP 3: Flash Sony Xperia 1 II XQ-AT51 Firmware Files

First of all, extract the Newflasher inside the same folder where the firmware files are present (that you got from the XpeirFirm tool in STEP 1).
Now launch the NewFlasher application on your PC.
Type in n and hit Enter. Then again type n and hit Enter. You should now be taken to the flashing stage.
Make sure to connect your device to start the upgrading process.
Now press Y and again Y to reply in the affirmative. The conversion process will then begin and once that is done, the tool will notify you that is now safe to disconnect your device.
Hence, disconnect it from the PC and then press and hold the Power key to boot it to the converted firmware.

That’s it, guys. We hope that you’ve installed the Stock Firmware on your Sony Xperia 1 II device successfully. Feel free to ask in the comments below for any queries.