Pixel 4a - downgrade CalyxOS (A13) to eOS 1.9


Can I fastboot install eOS recovery and v1.9 (A12) on a pixel 4a currently running CalyxOS 4.7 (A13)?


Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

if the phone is locked rollback protection will be enacted and you won’t be able to downgrade. The state is recorded in the vbmeta partition.

If the phone is unlocked it should accept the downgrade, but then re-locking, a vbmeta expecting a higher version could be a problem (I never tried, this is theory to me). So you should reset the vbmeta partition while unlocked.

I never had to do this myself, just read it in passing. Check those out:


Hello, I would not do this in any case, because the CalyxOS (A13) boot image does not correspond to that of /e/OS ‘S’ (A12) and there will be serious problems.

The safest way to install first the last firmware stock Android 12 (downgrading). Before flashing the stock factory images, you should delete the custom Android Verified boot key with fastboot erase avb_custom_key not to trust it. Only now is the system ready to be imaged with /e/OS ‘S’.


Without taking away from anything said by @anon29344687 Pixel devices are slightly easier to downgrade Android version than devices of some other manufacturers.

Android Flash Tool is available. Some users’ experience of Android Flash Tool is found on the forum Search results for 'Android Flash Tool' - /e/OS community.


Thank you @anon29344687 and @aibd for the info.

The device-flasher from Calyx can also be used to flash Google Pixel Android factory image (sunfish*factory.zip) . This type of installation is much more privacy friendly.