HTC released the Android 4.4.3 about a month ago and the unlocked HTC One M8, Sprint’s variant and T-Mobile’s model of the HTC One M8 flagship, have already received it and now is the time for AT&T HTC One M8 to receive the Android 4.4.3 KitKat update.
So if you own an HTC One M8 device from AT&T you should soon receive an update message in the notification panel informing you about the availability of newer firmware update for your handset.
Although AT&T has not posted an official changelog for the Android 4.4.3 update, like for the other variants, the AT&T ‘s One M8 models will receive along with it camera enhancements, improved Wi-Fi and Bluetooth performance, mobile network fixes, and optimizations for HTC Sense 6 features as well as security fixes.
The firmware is the build number 2.23.502.3, and it is around 660 MB in size, so we recommend you to use a Wi-Fi connection in order to avoid data charges.
To check manually for the update on your device, go to Settings -> AT&T Software Update -> Check for updates.
The users of Verizon version of HTC One M8 will get the Android 4.4.3 in mid-September so that they will have to wait a little bit.