The first iPod Nano was released in September 2005 in version with 2 GB or 4 GB to replace the iPod Mini. Although the models were just available in black and white colors, it had a color screen to view pictures. It weighted 1.5 oz (42.5 g), measured 3.5” x 1.6” x 0.27” (8.9 x 4 x 0.7 cm) and had a poor battery life: with just 14 hours of music playback when fully charged.

This “problem” was solved later, with the second generation, launched in September 2006. The battery life, from then till now, has increased to up to 24 hours of music playback. Even with video playback, battery life hasn’t changed in the next two generations. Nowadays, we can play up to 4 hours of video playback and we can’t wait for a more durable battery. Second generation was available in 2 GB, 4 GB and 8 GB in six different colors. 

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Figure 5:  the old Nano (left) and the new Nano.

Third generation was released in September 2007 with a “short and fat” design, measuring 2.75” x  2.06” x 0.26” (7 x 5.2 x 0.7 cm). It was also the heaviest Nano, with 1.74 oz (49 g) of weight. The screen became larger and with better resolution, to play videos for the first time. It was available in six colors and in 4 GB or 8 GB models.

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Figure 6: Both models side by side.

Now, in the fourth generation, Apple has brought back the “tall and slim” design, with some improvements: it is a little bit taller and considerably thinner than the second generation model, measuring 3.6” x 1.5” x 0.24” (9.1 x 3.8 x 0.6 cm) and with 1.3 oz (36.8 g) of weight. It feels a bit flimsy in the palm of your hand. The screen has the same size of the one of the third generation (320 x 240 / 204 ppi).