The iMac "Core i5" 2.3 21.5-Inch Aluminum (Mid-2017/Kaby Lake) features a 14-nm "Kaby Lake" 2.3 GHz Intel "Core i5" processor (7360U) with two independent processor "cores" on a single chip, a 4 MB shared level 3 cache, 8 GB of 2133 MHz DDR4 SDRAM that is reportedly onboard -- but actually can be upgraded later -- a 1 TB (5400 RPM) hard drive (256 GB SSD standard with an optional 1 TB "Fusion" Drive, which combines a 32 GB SSD and a 1 TB HDD, for the same price starting on August 4, 2020), and an "integrated" Intel Iris Plus Graphics 640 graphics processor that shares system memory. It also has a built-in "FaceTime HD" webcam and stereo speakers.

This model has a 21.5" 1920x1080 LED-backlit 16:9 widescreen IPS display with a fully laminated glass cover and an anti-reflective coating. The rear of the case is aluminum and is thicker in the middle and tapers to a razor thin 5 mm at the edges.

Connectivity includes four USB 3.0 ports, dual Thunderbolt 3 (USB-C) ports, Gigabit Ethernet, 802.11ac Wi-Fi, and Bluetooth 4.2.

Compared to its predecessor, this model essentially has the same external enclosure, but it has a more advanced processor, architecture, and graphics as well as Thunderbolt 3 (USB-C) ports.

By default, the "Mid-2017" iMac models originally shipped with a compact aluminum Apple Magic Keyboard and the multi-touch "Magic Mouse 2". For an additional US$30, you could upgrade from the default keyboard to the "Magic Keyboard with Numeric Keypad" and for an additional US$50, you also could upgrade from the Magic Mouse 2 to the "Magic Trackpad 2," which provides multi-touch and pressure-sensitive "Force Touch" capabilities.