Only the differences are shown. 24 specs stay the same.
+3you gain
−2you give up
iMac (21.5-inch, 2017) came out in June 2017. iMac (Retina 4K, 21.5-inch, 2019) came out in March 2019, almost 2 years later. iMac (21.5-inch, 2017) stopped getting new macOS versions at macOS Ventura 13. iMac (Retina 4K, 21.5-inch, 2019) stopped getting new macOS versions at macOS Sequoia 15.
Note on iMac (21.5-inch, 2017): Not listed as vintage or obsolete on Apple's page when checked. Base storage is a 1TB hard drive (5400 rpm); a 1TB Fusion Drive or 256GB SSD could be ordered instead.
Note on iMac (Retina 4K, 21.5-inch, 2019): Most storage you can order is a 1TB Fusion Drive. Price from Apple Newsroom (March 2019).
Updates & AI
macOS Ventura 13 → macOS Sequoia 15
Vintage: limited repairs
Chip & memory
2.3GHz dual-core Intel Core i5 → 3.6GHz quad-core Intel Core i3
4 CPU cores, 32 GB max memory, 256 GB storage
Screen
LED-backlit → Retina 4K
4096x2304
Price check
iMac (Retina 4K, 21.5-inch, 2019) launched at $1,299
Not currently sold refurbished by Apple.
All 12 differences
Updates & AI1 gain · 1 loss
Latest macOS
macOS Ventura 13›macOS Sequoia 15
What does this mean?
macOS is the software that runs the Mac: the desktop, Finder, the built-in apps, the settings and the security protection. Apple releases a new version every autumn.
A Mac on the newest macOS gets new features and regular security fixes. A Mac stuck on an older version keeps working, but over time apps start requiring a newer macOS, and security fixes stop. Apple has said macOS Tahoe 26 is the last version for Macs with Intel processors.
Matters most if: You use work, school or banking apps that need a recent macOS.
Apple repair support
Repaired by Apple›Vintage: limited repairs
What does this mean?
Apple counts from when it stopped selling the model, not from its release date. Vintage: Apple stopped selling it 5 to 7 years ago; repairs only while parts last. Obsolete: over 7 years ago; Apple no longer repairs it.
Checked against Apple's vintage and obsolete products list on 2026-10-11. Mac laptops may still get battery-only repairs for up to 10 years after Apple stopped selling them, if parts are available.
Apple Intelligence
No (same on both)
What does this mean?
Apple Intelligence is Apple's set of AI features: writing help that rewrites or proofreads your text, summaries of long emails and notifications, Clean Up in Photos, and the new Siri AI.
On Mac it needs Apple silicon, the M1 chip or later. Macs with Intel processors cannot get it. Which features you see also depends on your country and language.
Price1 change
Price check
iMac (Retina 4K, 21.5-inch, 2019) — launched at $1,299
- Used on eBay
- Refurbished on Back Market
- Apple does not currently sell this model refurbished
What your iMac (21.5-inch, 2017) sells for
- Apple Trade In estimate
- Sold listings on eBay
eBay may ask you to sign in to see sold prices.
Links open in a new tab. Prices are set by each seller and change daily.
Launch price (US)
$1,099›$1,299+$200
What does this mean?
The price Apple charged in the US on launch day for the lowest configuration, before tax.
This is not what the Mac costs today. More memory, storage or a faster chip cost extra. Older models drop in price over time, so check the used and refurbished links for current prices.
Chip & memory2 gains · 1 loss · 1 change
Chip options: iMac (21.5-inch, 2017)
- 2.3GHz dual-core Intel Core i5
Chip options: iMac (Retina 4K, 21.5-inch, 2019)
- 3.6GHz quad-core Intel Core i3
- 3.0GHz 6-core Intel Core i5
- 3.2GHz 6-core Intel Core i7
Chip
2.3GHz dual-core Intel Core i5›3.6GHz quad-core Intel Core i3
What does this mean?
The chip is the Mac's brain. Since late 2020 Apple uses its own chips (Apple silicon: M1, M2 and later). Before that, MacBooks used Intel processors.
Apple silicon Macs run cooler and much longer on battery than Intel MacBooks, and can run many iPhone and iPad apps. Intel Macs can run Windows directly with Boot Camp; Apple silicon Macs cannot.
Matters most if: You need Windows, or you want the longest battery life.
CPU cores
2›4
What does this mean?
The CPU is the part of the chip that runs your apps. More cores means it can work on more things at the same time.
More cores help most when exporting video, compiling code or running many apps at once. For browsing and email, the difference is small. Cores are only comparable within the same family: one Apple silicon core and one Intel core do not do the same amount of work.
Memory (most you can order)
16 GB›32 GB
What does this mean?
The most memory you could order from Apple for this model.
Only matters if you plan to buy a high-end configuration, for example for large video projects or software development.
Storage (base)
1 TB›256 GB
What does this mean?
Storage is where your files, photos and apps are kept. This is the amount in the cheapest configuration. 1 TB (terabyte) is 1,024 GB. Some older iMacs came with a hard drive or Fusion Drive instead of an SSD; the notes say when.
A desktop Mac can keep an external drive plugged in all the time, which makes a smaller internal drive easier to live with. Photo libraries and video fill storage fastest.
GPU cores
Not published by Apple (same on both)
What does this mean?
The GPU handles graphics: what you see on screen, games, and video and photo effects. Apple lists GPU cores for its own chips.
More GPU cores make games, 3D work and video editing smoother. "Not published by Apple" means the Mac uses Intel or AMD graphics, which Apple does not describe in cores.
Neural Engine cores
None (Intel) (same on both)
What does this mean?
The Neural Engine is a part of Apple silicon built for machine learning tasks, such as recognizing faces and text in photos.
It speeds up features like Live Text, photo search, voice dictation and Apple Intelligence, while using little battery. Intel Macs do not have one.
Memory type
DDR4 (same on both)
What does this mean?
Memory (RAM) is the working space for open apps and files. Apple silicon uses unified memory: one pool shared by the CPU, GPU and Neural Engine. Intel Macs list a memory type such as DDR4.
Unified memory is part of the chip, so it cannot be added later. Apple's spec pages list user-accessible memory slots only for the 27-inch Intel iMac and the 2019 Mac Pro.
Memory (base)
8 GB (same on both)
What does this mean?
How much memory (RAM) the cheapest configuration comes with, in gigabytes (GB).
More memory lets you keep more apps and browser tabs open without slowing down. 8 GB is enough for browsing and documents; 16 GB or more helps with photo editing, video and many apps at once. On Apple silicon Macs memory cannot be added later.
Matters most if: You keep many apps or tabs open, or edit photos and video.
Storage (most you can order)
1 TB (same on both)
What does this mean?
The most storage you could order from Apple for this model.
Only matters if you need to keep very large files on the Mac itself rather than on an external drive.
Screen2 changes · 2 unconfirmed
Resolution
1920x1080›4096x2304
What does this mean?
How many dots (pixels) make up the screen, across by down.
More pixels on the same size of screen make text and photos look sharper. macOS scales everything so text stays a comfortable size.
Display
LED-backlit›Retina 4K
What does this mean?
Apple's name for the screen. Retina means sharp enough that you cannot see the dots at a normal distance. Liquid Retina is Apple's name for its newer LCD screens with rounded corners. Liquid Retina XDR uses mini-LED lighting for much higher brightness and contrast.
XDR screens show HDR video and photos far brighter and with deeper blacks than Retina and Liquid Retina screens.
Screen type
LCD›Not published by Apple
What does this mean?
LCD screens use one light behind the whole screen. Mini-LED screens use thousands of tiny lights behind the screen, each lighting a small area that can dim on its own.
Mini-LED shows deeper blacks and much brighter highlights, which you notice most in HDR films and photo editing. For documents and browsing, both look good.
Brightness (SDR)
Not published by Apple›500 nits
What does this mean?
Nits measure brightness. This is the brightness Apple lists for everyday (SDR) content such as documents and websites, not the higher peak for HDR video.
A brighter screen is easier to read near a window or outdoors. 500 nits works well indoors. "Not published by Apple" means Apple's spec page for that model does not give a figure.
Screen size
21.5 in (same on both)
What does this mean?
Screen size measured corner to corner, in inches. One inch is 2.54 cm. Only iMac has a built-in screen; Mac mini, Mac Studio and Mac Pro use a separate display. Apple lists the 24-inch iMac's actual diagonal as 23.5 inches.
A bigger screen fits more windows side by side, and on an iMac it also sets how much room it takes on your desk.
120 Hz ProMotion
No (same on both)
What does this mean?
Hz (hertz) means times per second. A standard MacBook screen redraws 60 times per second (60 Hz). ProMotion goes up to 120 times per second (120 Hz) and slows down when nothing moves, to save battery.
Scrolling through pages, moving windows and animations look noticeably smoother.
Nano-texture display option
No (same on both)
What does this mean?
Apple offers an optional nano-texture screen: the glass surface is etched with a pattern too small to see, which scatters reflected light.
Reflections from windows and lights are greatly reduced, while the picture stays clear. It costs extra, and the screen should be cleaned only with the special cloth Apple includes.
Matters most if: You work near windows, outdoors, or under bright office lights.
Design1 change
Weight
5.44 kg›5.48 kg
What does this mean?
Weight in kilograms. 1 kg is about 2.2 pounds.
For a desktop Mac, weight matters when you move it or take it between places.
Height
45 cm (same on both)
Width
52.8 cm (same on both)
Depth
17.5 cm (same on both)
Speakers
Stereo speakers (same on both)
What does this mean?
How Apple describes the Mac's speakers on its spec page. Apple's wording varies between models. We show it exactly as Apple lists it.
Apple lists a single built-in speaker for Mac mini, Mac Studio and Mac Pro, so for music and films you will want speakers or headphones. Systems with force-cancelling woofers give fuller sound with more bass.
What's new
RSS feedAdded Mac mini, iMac, Mac Studio and Mac Pro
33 desktop Macs from 2017 onward, checked against Apple's tech specs pages, in one Mac section with the laptops, so you can compare a Mac mini with a MacBook Air. Specs a model does not have, such as a screen on Mac mini, show as Not applicable.
Added MacBook, MacBook Air, MacBook Pro and MacBook Neo
45 Mac laptops from 2016 onward, checked against Apple's tech specs pages. Older models appear on the timeline and open for comparison once they are checked. Switch to Mac at the top of the home page.
Added every iPad since 2010
45 iPad, iPad mini, iPad Air and iPad Pro models, checked against Apple's tech specs pages. Switch between iPhone and iPad at the top of the home page.