Android 4.4 has no security patches for over a decade. Android 9.0 includes years of security updates.
Before attempting to upgrade your device, make sure you:
Select > Select the ROM zip file > Swipe to Confirm .
Check the XDA Developers forum for your specific device to see which ROMs are actively maintained and have the best compatibility.
Before upgrading your Android device, make sure you're prepared for the process. Here are some essential steps to take: