The first-generation model was introduced on September 7, 2005, as a replacement for the iPod Mini,[2] using flash memory for storage.

On November 11, 2011, Apple announced a recall on this model of iPod nano due to a battery overheat issue.

The second-generation Nano featured a 40% brighter, "more vibrant" display,[11] a battery life upgrade (from 14 to 24 hours), and storage sizes of 2, 4, and 8 GB.

The third-generation Nano featured a 2-inch (51 mm) QVGA (320 x 240) screen and a shorter, wider, heavier design, with new colors.

New features include browsing via Cover Flow, a new user interface, video playback, and support for new iPod games.

On October 6, 2007, Apple released a firmware update (1.0.2) via iTunes that they said would improve Cover Flow and yield faster menu navigation.

At the Apple Let's Rock Event on September 9, 2008, the iPod Nano Fourth Generation was officially announced.

It was touted as "the most environmentally friendly iPod Apple has ever made", containing arsenic-free glass and a BFR-, mercury-, and PVC-free design.

"[19] At Apple's September 9, 2009 event, a fifth generation iPod Nano was unveiled with reduced prices on the larger models (at the time of release, the 8 GB was priced at $149 and the 16 GB at $179), a larger, 56.3-millimetre (2.22 in) diagonal screen (up from 50.8 millimetres (2.00 in) in third and fourth generation iPod Nanos), which is also wider,[20] integrated video camera with 16 special effects, microphone, FM radio with iTunes tagging (via RDS) and supporting multiple radio regions including Americas, Asia, Australia, Europe, and Japan.

As well as continuing to offer picture viewing and video playback, it also includes Live Pause, a built-in pedometer, Nike+iPod Support and a speaker.

[22] The fifth generation iPod Nano has nine finishes: Silver, Black, Purple, Blue, Yellow, Orange, Product Red, Green, and Pink.

At a media event on September 1, 2010, Apple announced the sixth generation iPod Nano, which, among many new features, is designed around a high-resolution square touch-screen.

On October 4, 2011, the iPod Nano 1.2 update was unveiled at the Apple "Let's Talk iPhone" event at the Town Hall, 4 Infinite Loop.

The (maximum) internal storage capacity was not increased compared with the previous model but a single, 16 GB version of the seventh generation iPod Nano was announced at the product launch.

It retains the Nike+iPod fitness option as well as an FM radio tuner which works when connected to headphones or a stereo jack.

On 15 July 2015, Apple refreshed the iPod Nano, offering five more subdued colors (gold, silver, blue, pink and space grey) compared to the original seven jewel tones, in addition to the (Product) Red model.

[44] The Nano sold its first million units in 17 days, helping Apple Inc. to a record billion-dollar profit in 2005.

In October 2005 a class action lawsuit was filed against Apple, with the plaintiffs seeking reimbursement for the device, legal fees, and "unlawful or illegal profits" from sales of the iPod Nano.

Lawyers for the plaintiffs claimed that the devices "scratch excessively during normal usage, rendering the screen on the Nanos unreadable, and violating state consumer protection statutes".

[50] In early 2009, Apple was in the process of settling a court case over the scratched iPod Nano screens.

Hesseldahl dismissed them as "stupid" and suggested that they benefitted "no one but the trial lawyers," but also suggested that Apple could have avoided litigation by offering "full refunds on unwanted Nanos" instead of charging a re-stocking fee and lengthening the return period from 14 days (when purchased through Apple retail or online) to 30 or 60 days.

[53][54] In another incident, a man's iPod Nano set his pants on fire while he was working at Hartsfield-Jackson Atlanta International Airport.

[59][60] Since 2010, users have been reporting the 6th generation iPod Nano's sleep/wake button remains stuck after months of use, making it impossible to activate the device without the help of a computer or a dock accessory.

[61] According to a technical inspection, the device uses double-sided tape to hold the button in place, indicating a possible design fault.

[62] On November 11, 2011, Apple announced the iPod Nano (1st generation) Replacement Program, intended to address concerns over overheating batteries.

[65] Because using the iPod nano 6th generation with a Mac computer requires iTunes 10 or higher, which in turn requires Mac OS X Leopard system software, Apple will upgrade the system software of participants running earlier versions of macOS, on request[citation needed] but this leaves users that do not have access to iTunes without a working device (because Apple changed the hashing of the music database which prevented the 6th generation iPod Nano from being used with open source software via libgpod).