Announced as "the biggest leap since the original iPhone," the iPhone 4 introduced an all-stainless steel body design. It featured a high-density 3.5-inch, 960x640 (326 ppi) IPS LED-backlit multi-touch "retina" display. The mobile and data antennas were integrated into the metal band around the sides. The device had a chemically hardened "aluminosilicate" glass front over a black frame and a matching glass back. A white version was announced on June 7, 2010, but did not ship until April 28, 2011. Both front and back surfaces on all models have an "oleophobic" oil-repellent coating.
It came equipped with dual cameras: a 5-megapixel rear camera capable of HD video (720p at 30 FPS) with a "backside illuminated sensor," 5X digital zoom, and an LED flash, plus a front-facing VGA-quality camera for FaceTime video calls over Wi-Fi. It also featured dual noise-canceling microphones.
The device was powered by an Apple A4 processor of unspecified speed, had 512 MB of RAM, and was available with 16 GB or 32 GB of internal storage. Network support included UMTS/HSDPA/HSUPA (850, 900, 1900, 2100 MHz) and GSM/EDGE (850, 900, 1800, 1900 MHz), along with 802.11g/n Wi-Fi and Bluetooth 2.1+EDR.
Like its predecessor, the iPhone 3GS, the iPhone 4 included a digital compass, A-GPS, and an accelerometer, but it added a 3-axis gyroscope to its sensor array, enabling more advanced 3D gaming experiences.
Apple's stated battery life for the iPhone 4 is up to 40 hours of audio playback, 14 hours of 2G talk time, 7 hours of 3G talk time, 6 hours of 3G internet use, 10 hours of Wi-Fi internet use, 10 hours of video playback, and 300 hours of standby.
In the US, the 16 GB and 32 GB models were initially priced at US$199 and US$299, respectively, for new or qualifying AT&T Wireless customers with a two-year contract. Starting June 14, 2011, Apple also offered an unlocked iPhone 4 in the US for US$649 (16 GB) and US$749 (32 GB), options which were discontinued on October 4, 2011.