After successful beta testing, finally Asus starts rolling out Android 8.0 Oreo to ZenFone 3 ZE520KL and ZE552KL variants. The incremental OTA (over the air) update with build number 15.0410.1712.31 starts getting on devices. You can download and install the ZenFone 3 WW_15.0410.1712.31_0 OTA to update or full firmware manually as given below. Before jump into the manual installation guide, let us see what is new in this update.
This update will bring all new features of Oreo, like PIP (Picture in Picture), notification dots, Smart text selection, Auto-fill, faster startup, app sign-in, Google Play Protect, alongside revamped settings menu and ZenUI launcher. Note that some existing apps, such as Mini Movie, Photo Collage, Do It Later, etc. excluded in this update, but you can install them from Play store, if needed.
It seems that Asus ZenFone 3 will not get Project Treble support with this Oreo update, while ZenFone 4 got it via the Oreo update.
If you have not received the OTA update notification on your device yet, check it by going to Phone Settings > About > System Update > update manually. Alternatively, follow the below manual installation guide.
Keep in mind that, to install the Oreo 15.0410.1712.31 OTA update, your ZenFone 3 (ZE520KL/ZE552KL) should be on stock recovery and runs on build number WW-14.2020.1712.85.
Important: This guide is for Zenfone 3 ZE520KL/ZE552KL and SKU WW. Do not install the firmware on other SKU (CN, TW, etc.). Check it by going to Settings > About > software information > Build number and see the software version for WW, CN, JP, etc.
How to Install ZenFone 3 Oreo Update Manually
Disclaimer: Follow the instruction at your own risk. We will not be liable if any damage occurs to your device and/or its components.
1. Download the firmware for Zenfone 3 (link above) and rename the file to ‘update.zip’ and save it on your phone.
2. Boot your phone into recovery mode (Switch off the phone and turn on by pressing Power + Volume Up buttons together).
3. In recovery, choose Apply update from sd card and then select the update.zip file.
4. After completing the installation, reboot your phone.
You have now successfully installed Android Oreo update on Asus Zenfone 3. Enjoy! Any question? Leave it in the comment section below. (Source)