Great news to all ASUS ZenFone 4, 5 & 6 owners! The software update from KitKat to Lollipop has began rolling out to all via OTA. You may check your phone software update now and performance the update.
Bare in mind, this is a major update thus the download size are huge. Recommended to download with WiFi connection present.
If you didn’t get the update and impatient to wait, you can update it manually by downloading the ROM and sideload it.