Android 13 was just released for Google's Pixel smartphones, and you can install it right away by going to your phone's settings and checking for an update. However, if you have a Google Pixel 6, Google Pixel 6 Pro, or a Google Pixel 6a, then be warned: trying to roll back to Android 12 after updating will trip your phone's anti-rollback protection. This means that the update to Android 13 is essentially permanent.

We spotted the warning on the Android 13 factory images page, where it says the following:

"The Android 13 update for Pixel 6, Pixel 6 Pro, and the Pixel 6a contains a bootloader update that increments the anti-roll back version. After flashing an Android 13 build on these devices you will not be able to flash older Android 12 builds."

This anti-rollback protection is not unlike mechanisms that some companies, such as Xiaomi, have employed in the past. For context, Xiaomi implemented anti-rollback protection by surprise on the Redmi Note 5 through a software update. When users went to downgrade they then bricked their smartphones, as they did not know they needed to be careful.

If you use your phone normally and don't flash between different system images, then you have nothing to worry about. However, if you're the kind of person that likes to jump between different versions, maybe hold off for a little bit. It's not clear if you'll actually brick your phone by downgrading after updating to Android 13, but it's better to be safe than sorry and to wait and see what happens. You also don't need to worry about it if you're using an older Google Pixel phone.

As for why this only affects the latest Pixel phones, it's not clear. However, all three of these devices are powered by Google Tensor, meaning that it might be something unique to Tensor, and might be why Google is implementing it. Anti-rollback protection is implemented through Verified Boot, and will ensure that a security vulnerability cannot be used by a malicious actor to install an older version of the Android system.

Source: Android factory images page