How to Downgrade Your Phone From Android 10 to Android 9
Android 10 is here – at least for Pixel devices. We generally recommend that everyone update their operating system to the latest and greatest version to take advantage of its features, security fixes, and bug fixes, but that doesn’t mean you are guaranteed a perfect new OS experience.
If you encounter any critical issues in Android 10 (including slowdowns) or are simply not familiar with Android 9, you can downgrade your device. While you’re probably better off deferring any fixes or backing up your information and factory resetting your phone to see if that solves any problems, the nuclear option still exists if you need it.
In this guide, we’ll walk you through the Android 10 to Android 9 downgrade process. We do it on the Pixel because that’s what we have (and what we have on Android 10). The process will be different for other Android devices – if you can downgrade at all – and we’ll cover them in a separate guide when Android 10 becomes more available.
Installing the Android SDK Platform-Tools
We will be using the ADB command line tool, short for Android Debug Bridge, to downgrade our Google Pixel 3 XL, which means we have to install the Android SDK Platform-Tools before we can do anything. Click this link, take the installer for Windows or Mac and unzip its contents to a folder of your choice.
Make sure your phone is fully up to date
This move sounds odd considering we’re trying to downgrade our Pixel device, but listen to me. Downgrading will not work if there are pending Pixel updates. So, to prevent this, go to Settings > System > Advanced > System Update and check if anything is available. If so, download the update, install it and restart your device.
Boot the old operating system image
For Google Pixel phones, the company provides a large list of operating system images to choose from. All I had to do was find my device (Pixel 3 XL) and get an image for Android 9.0. How simple it is. In my case, I used the most recent Android 9 image available: 9.0.0 (PQ3A.190801.002, Aug 2019)
Spoiler alert: This was actually an inappropriate file, which I’ll cover later in this article. Around this point, my first attempt to downgrade my device started to wane and I wanted to leave my initial thoughts here so you can get a complete idea of what to do and what not to do if you are following some downgrade routes that you first saw on Google.
Enable USB Debugging
For my computer to be able to talk to my phone via ADB, I also needed to enable USB debugging first. To do this, open Settings > About Phone , scroll down to find Build Number, and desperately click on it until you enable Developer Options on your device. Go back to Settings > System > Advanced and click Developer Options . Scroll down to the Debugging section and enable USB Debugging.
Spoiler alert: you’ll also want to enable “OEM unlocking” while you’re here, which I didn’t do until my second downgrade attempt. More on this later.
Connect your phone to your computer
Easy, right? When doing so, open an elevated command prompt (right-click and select “Run as administrator”) or “Terminal”. Navigate to where you unpacked the Android SDK Platform-Tools package.
Restart Android and start downgrading (try one)
Spoiler alert: At first I thought this was the right process. I was wrong. You can read why it doesn’t work in this section, or skip to the next section if you’re nervous and just want to downgrade your device without further education.
First, enter the following command to reboot your device into recovery mode. (You may have to first accept the USB debugging request on your device and then send the command again.)
adb reboot recovery
When I did that, I got a scary looking “No Command” screen on my device. To get to the main recovery menu, I just had to hold down the power button, press the “volume up” button and release the power button.
From there, I selected the “Apply update from ADB” option on my device using the volume buttons and confirmed this with the power button. My pixel then looked like this:
Back on my computer, I ran the following command to start downloading Android 9 back to my device:
adb sideload crosshatch-ota-pq3a.190801.002-13edb921.zip
Yes, that filename is the name of the Android 9 image that I downloaded from google. And, yes, it should be in the same folder as adb – don’t forget to move it there from your default downloads folder.
Not only could I see a small spike in activity on my device:
But I also have a small progress indicator (percentage counter) on my command line:
And then it all failed:
How to downgrade your device (successful attempt)
I suspect this method will allow you to update your device without any problems, but it actually takes a few more steps when you are trying to downgrade your device.
First, I had to restart my phone back to normal, go back to developer options in the Settings app, and enable an option I forgot about: OEM unlock .
Then I rebooted back to ADB by typing adb reboot bootloader at the command prompt. Then I had to install the Google USB Drivers by downloading them, unzipping them, opening the Windows Device Manager and manually updating the tagged Android device (by right clicking, choosing Update Driver and pointing to the directory where I had previously unzipped the Google USB Drivers).
I unplugged my phone and plugged it back in (I guess for luck) and I was able to confirm that my system was seeing it by typing fastboot devices at the command line.
Then I downloaded the Android 9 factory image from Google for my device – not the OTA image I extracted earlier – and placed it in the same folder as my ADB tool.
At this point, I felt quite ready. I unlocked my phone’s bootloader by typing fastboot flashing unlock at the command line. This prompted my device to issue a small frightening warning that I ignored; I used the volume buttons to select the new Unlock Bootloader option and confirmed with the power button.
While my phone’s bootloader was unlocked, I unzipped the factory image I previously downloaded straight into my ADB folder, so its contents floated among all the other files. (Do not unpack them into a new folder under the platform tools folder.)
Finally, I typed flash-all at the command line and crossed my fingers. And … that also failed because the image was said to be incompatible with my device. Sigh.
To work around this issue, I decided to try a full factory image refresh – the very first cross-hatch image available for my Pixel 3 XL, “9.0.0 (PD1A.180720.030, September 2018)”. I deleted the previous image from my platform tools folder, unzipped the contents of that image into the folder as before, and ran flash-all again. And everything seemed to work, since I was getting a lot more update processing data than before:
After about two minutes, the update finished and my device automatically rebooted. With a lot of fingers crossed – I think I was losing circulation by this point – I turned off my Pixel and manually rebooted it to Fastboot Mode while holding down the Power and Volume Down buttons. Then I entered fastboot flashing lock into the command line to lock the bootloader backup (which, again, required me to select the correct prompt on my phone).
Finally, I rebooted my device one last time by selecting the Start option from the fastboot screen (using the power button of course). And … Great Scott! – we went back to the past. This Pixel 3 XL is now on Android 9 with the old September 2018 security update:
A rundown of how to (actually) downgrade your device
I understand that this long twisty journey of downgrading my phone might be a little confusing, but I wanted to walk you through the process to show you the trial and error steps you might have to take when doing downgrade to an earlier version of your phone. device – whether it be Pixel, Samsung, or whatnot.
I’ve seen a lot of tutorials for downgrading Android, which tend to leave out one or two steps that are absolutely critical to the equation. Or worse, they leave you in limbo as you follow their steps and find that the process didn’t work for you. Watching me do this, hopefully you’ve upgraded your troubleshooting techniques if you find yourself stuck in the same way.
Here’s my final checklist for downgrading Pixel:
- Download and install the Android SDK Platform-Tools package.
- Download and install Google USB Drivers for your phone.
- Make sure your phone is fully up to date
- Enable developer options and enable USB debugging and OEM unlocking.
- Download the factory image for your device for whatever version of Android you want. (The most recent image may not be the optimal choice. Also, do not use an OTA image.)
- Use the command line or terminal to boot your device into fastboot mode and then unlock the bootloader.
- Use the “flash-all” command from the factory image to start downgrading.
- When finished, lock the bootloader of your device
In hindsight, it seems so simple, right?