This process will erase all data on your phone. Back up everything before starting.
Once complete, select "Wipe data/factory reset" , then "Wipe cache partition" , and finally "Reboot system now" . Method 2: ADB Sideload (For Older Zenfone 5 Models)
Visit the ASUS Download Center and search for your model (e.g., ZE620KL). Look for the specific "Downgrade to P" (Android Pie) image. Zenfone 5 Firmware Downgrade
Power off the phone, then hold Power + Volume Up to enter Fastboot/Droidboot mode. Command Execution: Connect the phone to your PC via USB. Open a command prompt in your ADB folder.
Copy the downloaded .zip file into the root directory (main folder) of a MicroSD card. Enter Recovery Mode: Power off the device. This process will erase all data on your phone
To prevent your phone from immediately updating back to the version you just left: Go to .
Ensure your phone is charged to at least 15% (ideally higher) to prevent shutdown during the process. Method 2: ADB Sideload (For Older Zenfone 5
This is the standard official method for ZenFone 5 (ZE620KL) users wanting to downgrade from Android 10 to Android 9.