The Nexus 5 was the first Android device to ship with Android 4.4 "KitKat", which had a refreshed interface, improved performance, improved
NFC support (such as the ability to emulate a
smart card), a new "
HDR+" camera shooting mode, native
printing functionality, a
screen recording utility, and other new and improved functionality. The device also shipped with Google Now Launcher, a redesigned home screen which allows users to quickly access
Google Now on a dedicated page, and allows voice search to be activated on the home screen with a voice command. Unlike the stock home screen, Google Now Launcher is not a component of Android itself; it is implemented as part of the
Google Search application. Until February 26, 2014, when it was released on Google Play Store for selected Android 4.4 devices, Google Now Launcher was exclusively shipped by default on the Nexus 5, and was not enabled in Android 4.4 updates for any other Nexus device. While an update to the Google Search application containing Google Now Launcher (which itself was tweaked to improve compatibility with other devices as well) was publicly released shortly after the Nexus 5's release, the launcher itself could not at the time be enabled without installing a second
shim application.
Hangouts, which now supports
text messaging, is used as the default text messaging application. In December 2013, the Nexus 5 began receiving the Android 4.4.1 update, which introduced HDR+, fixed issues with auto focus, white balance, and other camera issues. HDR+ takes a burst of shots with short exposures, selectively aligning the sharpest shots and averaging them using
computational photography techniques. Short exposures avoid blur, blowing out highlights, and averaging multiple shots reduces noise. HDR+ is similar to
lucky imaging used in
astrophotography. HDR+ is processed on the
Qualcomm Hexagon DSP. It also fixes low speaker volume output in certain applications. Android 4.4.2 update followed in a few days, providing further bugfixes and security improvements. In early June 2014, the Nexus 5 received Android 4.4.3 update that included dozens of bug fixes, while another mid-June 2014 Android 4.4.4 update included a fix for an OpenSSL
man-in-the-middle vulnerability. A developer preview of the Android 5.0 "
Lollipop" system image was released for the Nexus 5 after the annual
Google I/O conference held on June 26, 2014. The release version of Android 5.0 "Lollipop" was made available on November 12, 2014, in form of factory operating system images. On December 15, 2014, Android 5.0.1 "Lollipop" update began rolling out to Nexus 5 with build number LRX22C, the update was listed as being "miscellaneous Android updates." In March 2015, the Nexus 5 began receiving the Android 5.1 "Lollipop" update, which addresses performance issues and other user interface tweaks; however, it is known to introduce certain camera issues. In June 2015, Google made the Android 5.1.1 "Lollipop" update available for Nexus 5 aiming to fix the bugs that were not fixed by Android 5.1 update. In May 2015, a developer preview of
Android Marshmallow was made available for the Nexus 5. In November 2015, Nexus 5 started receiving
Android 6.0 "Marshmallow" update across the world. Following which Nexus 5 became one of the first devices to get an Android 6.0.1 Marshmallow update in December 2015. In August 2016, Google confirmed that the Nexus 5 will not receive an official Android 7.0 Nougat update, meaning that Android 6.0.1 Marshmallow is the last officially supported Android version for the device. The Nexus 5's
Snapdragon 800 has sufficient processing power to run Android 7.0 Nougat, as shown by successful tests with the Android N Developer Preview program (indeed the Snapdragon 800 is more powerful than the Snapdragon 410 which does support Nougat), and unofficial custom Nougat ROMs have been created for the Nexus 5. The Nexus 5 can also run other mobile operating systems such as
Ubuntu Touch. ==Reception==