Introduced on September 12, 2017, the iPhone 8 and the iPhone 8 Plus represented a "huge step forward for the iPhone," according to Apple CEO Tim Cook. The two devices "improve on everything we love about iPhone" with overhauled internals and a tweaked design, but the changes introduced were not as dramatic as the changes brought to the iPhone X, launched alongside the iPhone 8 and iPhone 8 Plus.

The iPhone 8 and iPhone 8 Plus mix a little bit of the iPhone X with a little bit of the previous-generation iPhone 7 and iPhone 7 Plus. The overall design is the same as previous-generation devices, but the iPhone 8 and the iPhone 8 Plus adopted glass bodies sandwiched in a a matching aluminum frame. Unlike the iPhone X, the iPhone 8 continued to include Touch ID Home button and thick bezels at the top and bottom of the display.

Presently available in three colors, Silver, Space Gray, and Gold, the iPhone 8 and the iPhone 8 Plus featured the most durable glass ever in a smartphone in a reinforced steel and aluminum structure that is IP67 water and dust resistant. The stereo speaker setup in the device was updated to be 25 percent louder with deeper bass.

The iPhone 8 includes a 4.7-inch display, while the iPhone 8 Plus features a larger 5.5-inch display. Both displays were upgraded with True Tone support, designed to adapt color temperature and intensity to the ambient light in a room for a more natural, paper-like viewing experience. 3D Touch and P3 wide color support for a greater range of colors continue to be available.

Apple chose glass for the body of the iPhone 8 and the iPhone 8 Plus to enable a Qi-based inductive wireless charging feature, which allows the two devices to be charged when placed atop any Qi-certified inductive charger.

Inside the iPhone 8 and iPhone 8 Plus, there's a six-core A11 Bionic chip, which Apple at launch said was the smartest, most powerful chip ever introduced in a smartphone. There are two performance cores that are 25 percent faster than the A10 Fusion chip in the iPhone 7, and four efficiency cores that are 70 percent faster.

With a second-generation performance controller, all six cores can be harnessed at the same time for much improved speeds when handling multi-threaded workloads. There's an Apple-designed 3-core GPU that's 30 percent faster than the previous-generation GPU, and two of the cores, the Neural Engine, make machine learning tasks faster than ever before.

Both the iPhone 8 and the iPhone 8 Plus feature improved cameras with better sensors that let 83 percent more light into the wide-angle camera compared to the previous generation. There's also a upgraded image signal processor built into the A11 that brings better low light performance, including faster autofocus, and there are new pixel processing techniques for sharpness pixel texture.

Apple also added hardware-enabled multi-band noise reduction, deeper pixels, and a new color filter for less noise, better color saturation, and a wider dynamic range of color.

The larger iPhone 8 Plus continues to offer a dual-lens camera setup with both an f/2.8 telephoto lens and a f/1.8 wide-angle lens, both of which have upgraded sensors. Optical image stabilization continues to be available for the iPhone 8 and the wide-angle lens in the iPhone 8 Plus.

Apple's Portrait Mode, limited to the iPhone 8 Plus's dual-lens camera system, has been updated with a Portrait Lighting effect to dynamically change the lighting in an image to mimic studio lighting techniques.

With the upgraded image signal processor and an Apple-designed video encoder that enables faster video frame rates and real-time image and motion analysis, video capture on the iPhone 8 and iPhone 8 Plus is better than ever. 4K video at 60 frames per second is supported, as is 1080p slow motion video.

Apple designed the iPhone 8 and the iPhone 8 Plus with augmented reality in mind. The cameras are calibrated for AR, there's an updated gyroscope and accelerometer to enable more accurate motion tracking, and the A11 Bionic offers world tracking and scenes while the GPU renders realistic graphics and the image signal processor offers real-time lighting estimation. iOS 11 introduced hundreds of new AR apps designed using ARKit, all of which can be experienced on iPhone 8 and 8 Plus.

The iPhone 8 was replaced by the iPhone XS, iPhone XS Max, and iPhone XR in September of 2018. Apple is now selling the iPhone 8 at a reduced starting price of $599 and the iPhone 8 Plus starting at $699