It was unveiled on October 31, 2013 and served as the launch device for Android 4.4 "KitKat", which introduced a refreshed interface, performance improvements, greater Google Now integration, and other changes.

The Nexus 5 received mostly positive reviews, praising the device's balance of overall performance and cost in comparison to other "flagship" phones, along with the quality of its display and some of the changes introduced by Android 4.4.

[15] The device was unveiled on October 31, 2013; it was made available for pre-order from Google Play Store the same day, sold in a black color with either 16 or 32 GB of internal storage.

[20] Google released two additional color options in February 2014, white and red, which had identical pricing and hardware.

[27][28] There are two variants of the Nexus 5, with varying support for cellular frequency bands; one is specific to North America (LG-D820), and the other is designed for the rest of the world (LG-D821).

Short exposures avoids blur, blowing out highlights and averaging multiple shots reduces noise.

[42] 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.

[43] The release version of Android 5.0 "Lollipop" was made available on November 12, 2014, in form of factory operating system images.

[54] The Nexus 5 received mostly positive reviews; critics felt that the device provided a notable balance between performance and pricing.

[55][56] Although noting nuances with its display, such as its color reproduction and low maximum brightness in comparison to competitors, CNET praised software features such as the new phone dialer interface and Google Now integration on the home screen, but did not believe KitKat provided many major changes over its predecessors.

Hangouts as the default text messaging app was criticized for its user interface and for attempting to force the use of a Google service, while the quality of photos taken with the device was described as being "great, but it didn't particularly blow me away."

In conclusion, Engadget argued that "whether or not it was the company's intent, Google is sending a message to smartphone makers that it's possible to make high-quality handsets without costing consumers the proverbial arm and leg.

"[55] Compared to the LG G2 which was released earlier and shares the same manufacturer and much of the same hardware, the Nexus 5 has a lower-quality rear camera and smaller battery to hit a cheaper price point.