Apple 21.5in iMac (3.6GHz, 4-core, 2019) vs Apple MacBook Air (2019) full review

The MacBook Air has always been one of Apple’s most popular Macs, but when Apple failed to update it for over three years everyone thought that the Air had breathed its last. When in October 2018 Apple updated the MacBook Air there were celebrations aplenty. The new MacBook Air has all-new, smaller and thinner design, new colour options, and a Retina display. And best of all, in July 2019 Apple reduced the price of the MacBook Air so it now starts at £1,099/$1,099.

There's an iMac that's priced similarly at £1,049. Does this mean that the two machines are comparable? Most definately not, as you will see if you read on. But that doesn't mean it's not worth paying a little more to get a better speced iMac rather than a MacBook Air, we'll look at the options.

Here we will compare both models of MacBook Air with the various 21.5in iMac units.

MacBook Air


Before the MacBook Air was updated in 2018 there were rumours that Apple would be pricing it at under £1,000/$1,000. This didn’t happen - aside from Apple keeping the older model on for £949/$999 for just under a year (as of July 2019 the older-style MacBook Air is no longer available).

The 2018 MacBook Air - which was updated in July 2019 to add True Tone to the screen, but with no other changes to the specs - now costs £1,099/$1,099. £100/$100 less than it did at launch in October 2018.

For that you get:

  • 1.6GHz dual-core 8th-gen Intel Core i5 processor with 3.6GHz Turbo Boost
  • 128GB SSD storage
  • Intel UHD Graphics 617 
  • 2560x1600 Retina display (now with True Tone)
  • For: £1,099/$1,099

There’s a second MacBook Air available for £1,299/$1,299 (also £100 less than it was). The only difference is that it offers 256GB storage.

  • 1.6GHz dual-core 8th-gen Intel Core i5 processor with 3.6GHz Turbo Boost
  • 256GB SSD storage
  • Intel UHD Graphics 617 
  • 2560x1600 Retina display (now with True Tone)
  • For: £1,299/$1,299

You can buy a MacBook Air from Apple here.

MacBook Air

As we said above, there is a iMac that costs a few pounds less than the MacBook Air: £1,049/$1,099. However there are a number of reasons why it's not a good deal, as we will discuss.

Here's what you get:

  • 2.3GHz dual-core 7th-gen Intel Core i5 processor with 3.6GHz Turbo Boost
  • 1TB hard drive
  • Intel Iris Plus Graphics 640
  • 8GB 2133 MHz RAM
  • 1920x1080 non-Retina display
  • For: £1,049/$1,099

The older generation processor means that this Mac won't perform as well as the MacBook Air. Another thing holding it back is the hard drive: 1TB might sound promising, but PCs with hard drives are far slower than those with SSDs. Plus, the lack of Retina display is a disadvantage. It's hard to recommend this machine at over £1,000. If Apple was selling it for £700 we might be more approving of it.

But there are other iMacs on offer. The rest of the iMac range were updated in March 2019 and include the following 21.5in models (there are also 27in iMacs but we won't discuss them here as they definately aren't comparable to a MacBook Air!)

  • 3.6GHz quad-core 8th-gen Intel Core i3 processor
  • 1TB hard drive
  • Radeon Pro 555X graphics 
  • 8GB 2400MHz RAM
  • 4K 4096x2304 Retina display
  • For: £1,249/$1,299

The top-of-the range 21.5in iMac actually has a similar spec to the entry-level 27in model.

  • 3.0GHz 6-core 8th-gen Intel Core i5 processor with 4.1GHz Turbo Boost
  • 1TB Fusion drive
  • Radeon Pro 560X graphics 
  • 8GB 2666MHz RAM
  • 4K 4096x2304 Retina display
  • For: £1,449/$1,499

You can buy an iMac from Apple here.

iMac 2019

Before Apple cut the price of the MacBook Air by £100/$100 in July 2019 there was only a jump of £100/$100 between the MacBook Air and the 2019 Retina iMac. Since the price change that difference is now £200/$200.

What do you get for spending £200/$200 more? We'll discuss the differences in more detail below but its clear that you get more for your money if you choose an iMac, with faster processors, better RAM, better graphics and more storage, for just £200 more. 

But now that the MacBook Air costs £200 less than the 2019 Retina iMac, it certainly looks a lot more attractive, and the power it offers and the now lower price is impressive.

Before we discuss how the specs compare though, we'll quickly discuss the other more obvious difference: design. 


The iMac has had the same design for more than a decade. It’s a nice design, but, as we mention in our reviews of the 2019 21.5in iMac and 27in iMac, the iMac would benefit from a few changes to the design. We’d like to see smaller bezels around the screen so that the screen could be larger without the dimensions having to change much. We’d also like the screen to be more adjustable so that you can position it on your desk in an ergonomically friendly way. 

Massive bezels on iMac

The MacBook Air had a complete redesign in 2018, although it’s still got the trademark wedge shape that tapers to a smaller point, thereby keeping the laptop light and giving the impression that it is thinner than it is. As laptops go, it’s one of the most attractive laptops you can buy, and comes in Gold, Silver and Space Grey.

MacBook Air

What it all comes down to is whether you need to be able to carry the computer around with you or if it will always be located in the same place. If you don’t need to be able to move it the iMac will be a good option, but if you will be carrying it to and from work or university then it has to be a laptop.


Both the iMac and the MacBook Air have Retina displays (with the exception of the £1,049/$1,099 iMac.

The iMac display is superior predominantly because it is bigger, but there is more to it than that.

The MacBook Air screen measures 13.3in. The display is LED-backlit and uses IPS technology. It has a 2560x1600 native resolution at 227 pixels per inch. And it supports millions of colours. In July it gained True Tone, which is a technology that can adjust the brightness and colour to ensure that colours look correct depending on the light in your surroundings.

The iMac screen measures 21.5in. It offers 4,096x2,304 resolution (4K) and supports 1 billion colours. This is the most vibrant Retina display you can get on a Mac. It lacks True Tone though. Perhaps the feature is less necessary when the Mac tends to remain in one position.

You may find the screen on the MacBook Air cramped for working on if you often have a lot of windows open. We have a 13in MacBook Pro to work on and always use it plugged into an external monitor. You could also plug your MacBook Air into an external monitor but note that it has only two USB Type C ports, one of which is required for charging.

MacBook Air

The iMac screen, at 21.5in is probably a better size for working on, it would also be great for watching films and slide-shows on.

Features & Specs

There are various differences between the iMac and the MacBook Air in addition to the obvious fact that one is a laptop and the other a desktop. Here we'll look in more detail at the components, explaining why one is a better choice than the other.


The iMac we are looking at here has a 3.6GHz 8th-generation Intel Core i3 quad-core processor. That's four cores on the iMac rather than two for the MacBook Air. Because the iMac has a i3 processor it doesn't have Turbo Boost, but that probably won't matter to you as it's pretty fast already.

The MacBook Air has a 1.6GHz dual-core Intel Core i5 eighth-generation processor. This sounds worse than the one in the iMac, and it is. There are two processors here compared to the four in the quad-core iMac. However, the MacBook can Turbo Boost up to 3.6GHz, while the iMac, due to it using an i3 chip, can’t Turbo Boost to get extra power when needed.

The quad-core processor in the iMac is always going to beat the MacBook Air though.


The MacBook Air comes with 8GB of 2133MHz LPDDR3 RAM as standard, and can be configured to take 16GB.

Like the Air, the iMac comes with 8GB of RAM, but in this case it is 2400MHz DDR4 memory, which is faster. There are also iMacs available with even faster 2666MHz memory. The 21.5in iMac is configurable to 16GB or 32GB RAM (the 27in can go to 64GB).

If you think you are going to want to update the RAM in your Mac in the future the best option for you would be the 27in iMac, which costs a lot more than the 21in version, but has a hatch on the back that can be opened so that you can add more RAM (as seen in the image below). If you want to add more RAM to the 21.5in iMac it can only be done via an Apple authorised service provider. It's impossible to add more RAM to the MacBook Air.

iMac RAM hatch


If you were thinking the 1TB of storage in the iMac is an advantage you are wrong.

It might look good on paper that the iMac comes with a 1TB hard drive but that’s a 5400-rpm drive that will slow the Mac down considerably. Our advice here would be to switch from the hard drive to a Fusion Drive, a build-to-order option that costs an extra £90. That will give you the same 1TB storage, but you will also have a small SSD that can store things so that they can be accessed quickly. This will speed up operation.

Alternatively an even better solution is to opt for a 256GB SSD inside your iMac - a £180 build-to-order option - and get an external hard drive or pay for iCloud if you really think you need the extra storage. 2TB iCloud storage costs £6.99/$9.99. Here’s how much iCloud costs.

The MacBook Air on the other hand offers a 128GB PCIe-based SSD with options to configure it to 256GB, 512GB or 1.5TB SSD. While 128GB storage might not sound a lot, it has an advantage simply because it’s an SSD.

With a SSD you will get better performance and faster boot-up time. A hard drive will give you more GB of space for your money but there are many disadvantages, including the fact that because there are moving parts they can be noisy, they fail more often than SSDs, magnets can erase the data, and they require more power.

The most obvious difference: with an SSD or Fusion Drive your Mac will start up almost instantaneously. With a hard drive you might as well go and make a cup of tea while you wait for it to start up.


The MacBook Air comes with an Intel UHD Graphics 617. That’s a graphics card that is integrated onto the processor and shares memory with the system.

The entry-level iMac also has an integrated card, but we are ignoring that machine. The rest of the iMac range have discrete graphics cards with their own memory. So you will have a better experience with games and any graphic intensive apps if you choose one.

iMac 21.5in screen

But do you need a discrete graphics card like the one inside the iMac? If you are going to be playing games on your Mac then the iMac’s a better bet - but you might actually want to consider spending a bit more to get a superior iMac with an even better graphics card.

Alternatively, if you really needed better graphics for your MacBook Air you could plug in an external GPU, but at around £600/$600 we doubt that is a feasible solution for many.

But if you are just going to be using your Mac to surf the web, edit your photos and make the odd home movie, write an essay, or input data in a spreadsheet, then a discrete graphics card isn't going to be essential.

Ports & Peripherals

When it comes to ports the Air is limited with just two Thunderbolt 3 (USB‑C) ports, one of which needs to be used for charging.

Air ports

The iMac, on-the-other-hand, has two Thunderbolt 3 (USB‑C) ports, four USB 3 ports, one SDXD card slot and Gigabit Ethernet.

Thanks to the Thunderbolt 3 ports the MacBook Air can support one external display with 5120x2880 resolution at up to 60Hz, or up to two external displays with 4096x2304 resolution at up to 60Hz.

The iMac can go one better though, offering support for one 5120x2880 (5K) external display at 60Hz with 1 billion colours, or two 3840x2160 (4K UHD) external displays at 60Hz with 1 billion colours, or two 4096x2304 (4K) external displays at 60Hz with millions of colours.

Back of iMac

Both the MacBook Air and the iMac have a 720p FaceTime HD camera. Don’t expect this camera to be as good as the one on the front of your iPhone though.

Finally, both the Air and the iMac support 802.11ac Wi‑Fi wireless networking; IEEE 802.11a/b/g/n compatible, Bluetooth 4.2 wireless technology.


The MacBook Air has the advantage of being a lightweight laptop that you can carry around, and it comes with an SSD, so you don’t have to spend extra upgrading it so as not to be lumbered with a slow hard drive.

But, if what you want is the most powerful Mac you can get for your money then the iMac is a good option. The £1,249 iMac (or £1,339 iMac if you add the Fusion Drive, or an SSD, as we recommend) is significantly more powerful than the MacBook Air. It also offers more ports, better graphics, superior RAM, and a faster, quad-core processor.

However, there’s one other option to consider if you are looking for a powerful Mac and you are happy to choose a desktop. The Mac mini, which we compare to the iMac here, costs £799/$799 for an identical 3.6GHz quad-core 8th-generation Intel Core i3 to the one in the iMac. The mini benefits from a 128GB SSD, but lacks the discrete graphics of the iMac, and doesn’t come with a display. Despite that, at £450/$450 less than the iMac you may well want to consider it.

Find the best price

Best prices today

Retailer Price Delivery  

Price comparison from over 24,000 stores worldwide