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Apple A-Z » Mac

21.5-inch iMac

21.5-inch iMac

⚠️ This content has been preserved for historical or organizational purposes, but is no longer being maintained. It is unlikely to be updated further and may contain duplicate or outdated information.

The 21.5-inch iMac 4K was launched in 2015. It shared all the same design elements as the larger iMac 5K and used the classic unibody all-in-one design. This iMac was priced to be education-friendly with decent specs through the lineup. It was replaced by the 24-inch iMac in 2021.

No longer sold by Apple. See 24-inch iMac

● 21.5-inch 4K Retina Display
● 500 nits and P3 color gamut
● up to 6 core i7
● up to 32 GB RAM
● up to Radeon Pro Vega 20
● up to 1TB SSD
● Find great iMac deals
● Discounted prices start at $999

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Starting at $1,099, the 21.5-inch iMac is what you would expect from an entry-level Apple desktop Mac with Intel. Middling specs, a beautiful display, and modern processors made this a solid buy for many casual users. It is no longer sold by Apple but is supported by the latest version of macOS.

The baseline iMac was equipped with a 3.6GHz quad-core 8th generation Intel Core i3 processor. Other processor options included a 3.0GHz 6-core 8th generation Intel Core i5, and 3.2GHz 6-core 8th generation Intel Core i7 processors.

Information found below was written before the release of Apple's 24-inch iMac with M1 processor.

21.5-inch iMac features


Since the last significant design upgrade in 2014, Apple has changed almost nothing about the iMac's outward appearance. It has used the same 21.5-inch screen, 4K resolution, P3 color gamut, and 500 nit brightness through every incremental upgrade.

The unibody design hasn't changed, either. The frame tapers at 5mm up to a large hump in the rear to house the internal components. There is a sizable chin under the screen. Cooled from an internal fan and vented below the screen, some Apple watchers worry that this design will reach its thermal limits in the coming generations.

The iMac hides its exhaust vents underneath the screenThe iMac 4K hides its exhaust vents underneath the screen.


The 21.5-inch iMac with a 4K display comes with 8th generation Intel Core i3 or i5 chipsets by default. Users can also configure it at the time of purchase to include an i7.

For graphics, customers can select between the Radeon Pro 560X with 4GB of GDDR5 memory, or go all out with a Radeon Pro Vega 20 with 4GB of HBM2 memory. However, users needing more power who are willing to spend that much will likely be better off with the 27-inch iMac or the iMac Pro.

Upgrade Path

Unlike its 5K counterpart, there is no rear door to access the RAM, but the RAM is upgradeable if the machine is disassembled. The smaller iMac has the same ports as the 27-inch iMac: two Thunderbolt 3 and four USB-A, an SD card reader, a headphone jack, and a gigabit Ethernet port. 

The ports on an iMacThe iMac 4K comes with the same ports as its larger 5K counterpart

If users need more graphics capabilities, Thunderbolt 3 allows users to attach powerful external GPUs, such as those from Black Magic. This means users can purchase a new external GPU instead of replacing the entire iMac when requiring newer specs.

Useres can also use the Thunderbolt 3 ports to attach external monitors. The iMac 4K can drive a single 5K display or two 4K displays. Apple had recently partnered with LG to produce official monitors for Macs, like the LG 23.7-inch 4K UltraFine Display.

History of the 21.5-inch iMac


The iMac line was updated on August 4 to be up-to-spec with other Macs released in 2020. The naming scheme shifted to address the display size, not the resolution, to be more standardized.

While Apple didn't make any substantial updates to the 21.5-inch iMac, users can now configure it with SSD storage by default. All other specs remain the same.

Many Apple observers expect the 2020 updates to be the last for the current design of iMac models. The next update should arrive in 2021 with a larger display and running Apple Silicon. Rumors show a 24-inch iMac is likely to hit the market first.


When Apple updated the lineup in 2019, it gave the modern iMac 4K some decent speed boosts, new intel chipsets, better GPU options, and better memory. The biggest issue was that the baseline hard drive is still the same slow 1TB HDD drive that users may wish to upgrade.

Everything else remained the same, with the same design and screen.

Geekbench scores show obvious upgrade path for usersGeekbench scores show an obvious upgrade path for users


2017 brought several updates to the iMac, with new Kaby Lake Intel processors, discrete Radeon Pro GPUs, and Thunderbolt 3 all arriving that year. This meant speed improvements across the board, making the base iMac 4K a much better value than before.

Despite the other speed improvements, the entry-level machine still had a slow HDD that needed upgrading.


Apple announced the iMac 4K in fall 2015 to no one's surprise. After the 27-inch iMac 5K released the year prior, it was only a matter of time before the smaller 21.5-inch iMac received similar treatment. It released with a new feature to the iMac line: support for P3 color gamut.

Alongside the 4K model, Apple updated the iMac 5K with the same new features and launched upgraded peripherals. Shipped in-box with the new iMacs, the new Magic Mouse, Magic Trackpad, and Magic keyboard featured a modified design and rechargeable batteries.

21.5-inch iMac Pricing

The 21.5-inch iMac with 4K display ships with a base configuration of 3.6GHz quad-core i3, 8GB DDR4 RAM, 256GB SSD, and Radeon Pro 555X graphics for $1,299. This can be configured with faster Intel processors up to the intel core i7, an SSD or Fusion Drive of up to 1TB, RAM going up to 32GB, and improved graphics with a Radeon Pro Vega 20.

Maxing this machine out would cost $3,049. For those wanting the best balance of specs and price, AppleInsider recommends the middle-tier 21.5-inch iMac for $1,499.

Top 21.5-inch iMac deals button with piggy bankUnlock Insider 21.5-inch iMac Prices button

Common 21.5-inch iMac Questions

Is the 21.5-inch iMac good for gaming?

The more expensive configurations should handle gaming fairly well. However, since macOS isn't nearly the gaming platform that Windows is, you'd need to use Bootcamp to get the best gaming experience.

Is the 21.5-inch iMac upgradeable?

No, the 21.5-inch iMac does not have user-installable RAM or other components.

What comes in the box of the 21.5-inch iMac?

Apple includes the following in the box:

  • iMac
  • Magic Mouse 2
  • Magic Keyboard
  • Power cord
  • Lightning to USB Cable

How much does the 21.5-inch iMac cost?

21.5-inch iMac pricing starts at $1,299. This base configuration includes a 3.6GHz quad-core i3 processor, 8GB DDR4 RAM, 256GB SSD, and Radeon Pro 555X graphics.