The official Android 4.4 KitKat update is available to some Google 4 users already, thanks to Over-the-Air notifications. Google released a bug-fix update to Nexus devices as well. The official Android 4.4 KitKat bears the build no. KRT16S and weighs 238 MB.

Before the user installs the official 4.4 KitKat update, the Nexus 4 should have at least 20 percent battery first. A reliable WiFi connection is also advisable for an efficient official Android 4.4 KitKat update installation.

The official firmware is released in stages, in different regions but you can expect the download link for the KitKat firmware has already emerged online, alongside a step-by-step guide on how to install Android 4.4 KitKat via a manual process. Those who are too excited and cannot wait for the OTA notification any longer can follow the manual installation process instead to update their Nexus 4 Android 4.4 KitKat update. The file below can be used by Nexus 4 devices that currently run stock JWR66Y.

Download Link

To flash, the owner can use the "adb sideload" command via adb and the Android SDK instructions. If stock with root and recovery, flash the .zip file through recovery. Oftentimes this works.

The KRT16S firmware is also compatible with other Nexus devices such as the Nexus 7 Mobile, Nexus 7 WiFi, Nexus 7 2013 WiFi, Nexus 7 2013 Mobile and Nexus 10.

The KitKat update brings pretty minor tweaks, including a backup service improvement, updated APNs for various carriers, and code that handles rare issues with the 3G Nexus 7 (2012) radio. There's also an emergency fix for a bug that could result in loss of access to encrypted disks on a device upgrading from 4.3 Jelly Bean to 4.4 KitKat.

A security improvement called Scypt is a new Key Derivation Function that makes brute force attacks more complex and expensive, ensuring full-disk encryption. However, if a user enters an incorrect passphrase, the upgrade could scramble the cryptographic keys and make the owner's data inaccessible.

Other Android 4.4 KitKat upgrade changes include: backup service with registration occurring dynamically, tilapia (2012 GSM Nexus 7) radio issues resolved and updated WLAN driver.