Note : No Root || Bootloader Unlock not required

Simple to Flash Guide

Download the Archive add to the download link

Extract and Locate the MSM download Tool

Step 2. Open “MsmDownloadTool V4.0.exe” program by double-clicking on it. Set target to “OP”

Step 3. Choose “other” and next.

Step 4. Open Device Manager on Windows.

Step 5. Power off your phone and connect a USB cable to your computer.

Step 6. Hold down Volume Up and Down until you hear Windows sound and see “Qualcomm EDL” show up in Device Manager under Ports(COM & LPT).

Step 7. Immediately hit the “Enum” button on the MSMDownloadTool.

Step 8. Select the “COM” of your device and hit Start.

Now, make sure you do the Steps 6 through 8 quickly as if you don’t, your phone may reboot.

Extra – This unbrick method will WORK ON ALL MODELS of OnePlus 8 or 8 Pro. If you need to change to a different firmware(such as European/Indian/Chinese), you can simply download the firmware on OnePlus website then flash using System->System update->Settings icon->Local upgrade. Make sure to put the firmware on the root directory of your storage.

Also, if you are reading this in the future, simply upgrade your OxygenOS through OTA after unbricking.

After unbricking, your OnePlus 8 or 8 Pro will be completely back to stock factory and your bootloader will be locked again. So if you want to root or install custom ROMs, simply unlock your bootloader again.