Display
21.5-inch (diagonal) LED‑backlit display
1920x1080 resolution with support for millions of colours
Retina 4K display
21.5-inch (diagonal) Retina 4K display
4096x2304 resolution with support for 1 billion colours
500 nits brightness
Wide colour (P3)
Processor
2.3GHz
2.3GHz dual‑core Intel Core i5 (Turbo Boost up to 3.6GHz)
3.6GHz
3.6GHz quad‑core Intel Core i3
3.0GHz
3.0GHz 6-core Intel Core i5 (Turbo Boost up to 4.1GHz)
Memory
8GB of 2133MHz DDR4 memory
8GB of 2400MHz DDR4 memory
8GB of 2666MHz DDR4 memory
Storage
1TB
1TB (5400-rpm) hard drive
1TB
1TB (5400-rpm) hard drive
1TB
1TB Fusion Drive
Graphics
Intel Iris Plus Graphics 640
Radeon Pro 555X with 2GB of GDDR5 memory
Radeon Pro 560X with 4GB of GDDR5 memory
Video Support and Camera
FaceTime HD camera
Simultaneously supports full native resolution on the built-in display at millions of colours (21.5-inch) or 1 billion colours (21.5-inch 4K) and:
One 5120x2880 (5K) external display at 60Hz with support for 1 billion colours, or
Two 3840x2160 (4K UHD) external displays at 60Hz with support for 1 billion colours, or
Two 4096x2304 (4K) external displays at 60Hz with support for millions of colours
Thunderbolt 3 digital video output
Native DisplayPort output over USB-C
Thunderbolt 2, HDMI, DVI and VGA output supported using adapters (sold separately)
Audio
Stereo speakers
Microphone
3.5mm headphone jack
 
Support for Apple iPhone headset with microphone
 
Connections and Expansion
Headphone SDXC card slot USB 3 Thunderbolt 3 (USB-C) Gigabit Ethernet
3.5mm headphone jack
SDXC card slot
Four USB 3 ports (compatible with USB 2)
Two Thunderbolt 3 (USB-C) ports with support for:
 
DisplayPort
Thunderbolt (up to 40 Gbps)
USB 3.1 Gen 2 (up to 10 Gbps)
Thunderbolt 2, HDMI, DVI and VGA supported using adapters (sold separately)
 
10/100/1000BASE-T Gigabit Ethernet (RJ-45 connector)
Kensington lock slot
Input
Magic Keyboard
Magic Keyboard comes standard with your iMac. It’s wireless and rechargeable (so you won’t be replacing batteries), with an ultra-compact, edge-to-edge design that wastes no surface space. It has a stable scissor mechanism, optimised key travel and a low profile that provide control and comfort. And it pairs immediately with your iMac straight out of the box.
Magic Keyboard with Numeric Keypad
You get all the functionality of Magic Keyboard, with an extended layout that makes it even easier to work and play. Magic Keyboard with Numeric Keypad includes document navigation controls — page up, page down, home and end — and full-sized arrow keys that are perfect for navigating pro apps, moving through spreadsheets and playing games.
Magic Mouse 2
Magic Mouse 2 comes standard with your iMac. The design of Magic Mouse 2 lets it glide smoothly across your desk. And since it supports Multi-Touch, you can use simple gestures on its surface to do things such as swipe between web pages and scroll through documents.
Magic Trackpad 2
If you prefer using a trackpad, Magic Trackpad 2 gives you the full range of Multi‑Touch gestures and introduces Force Touch to the desktop. Sensors underneath the trackpad surface detect subtle differences in the amount of pressure you apply, bringing more functionality to your fingertips and enabling a deeper connection to your content. This design, along with a low profile, makes it extremely comfortable to use.
Wireless
Wi-Fi
802.11ac Wi-Fi wireless networking
IEEE 802.11a/b/g/n compatible
Bluetooth
Bluetooth 4.2 wireless technology
Size and Weight
52.8 cm
(20.8 inches) 45.0 cm
(17.7 inches)
21.5-inch iMac
Height: 45.0 cm (17.7 inches)
Width: 52.8 cm (20.8 inches)
Stand depth: 17.5 cm (6.9 inches)
Weight: 5.66 kg
(12.5 pounds)2
52.8 cm
(20.8 inches) 45.0 cm
(17.7 inches)
21.5-inch iMac with Retina 4K display
Height: 45.0 cm (17.7 inches)
Width: 52.8 cm (20.8 inches)
Stand depth: 17.5 cm (6.9 inches)
Weight: 5.60 kg
(12.3 pounds)2
Electrical and Operating Requirements
Line voltage: 100–240V AC
Frequency: 50Hz to 60Hz, single phase
Operating temperature: 10° to 35° C (50° to 95° F)
Relative humidity: 5% to 95% non-condensing
Operating altitude: tested up to 3,000 metres (10,000 feet)