If you are thinking of buying a MacBook Air there are various things to consider. You may be wondering which model to buy: the 11in or 13in version? You may be considering whether to add extra storage or RAM to your MacBook Air. Or you may be confronted with a cut price MacBook Air from 2012 or one of the models from 2013, and the question of whether that would be a good buy in comparison with the newer models.

An important aside: Apple updated the MacBook Air on 29 April, reducing the price of the MacBook Air and making a minor tweek to the processor. Despite this recent update, Apple may  introduce a Retina version of the MacBook Air later this year. Rumours point towards an update that could introduce a 12in model with a Retina display, for example - read more in our MacBook Air with Retina display rumour round up.

Read our Best Mac buyers guide | New MacBook Air (2015, 11-inch) preview

We had anticipated this price change on the basis of the minor difference in pricing between the 2013 MacBook Air and the MacBook Pro with Retina display. There was just £150 difference between the 2013 13in models [read more about the difference between the Air and Pro here]. Our advice last year was that if you are on the market for a new laptop it may have been worth paying a few pounds more and getting the MacBook Pro with Retina display. Now the price between the 13-inch models is £250, which is enough of a difference to make the question more of a challenge, so we have updated this article accordingly.

When Apple launched its 2013 MacBook Air last June the decision of which model to buy become harder than ever and this hasn't really changed with the introduction of the 2014 models. In the past it was a simple sacrifice or power and screen size for portability, but the 2013 and 2014 models are so similar in spec that it all boils down to weight, size and battery life. There really is no other differentiator. In this article we will help you decide which MacBook Air will best suit your needs.  

Apple has now launched a low-cost iMac that offers comparable specs and a comparable price. We compare the new entry-level iMac and the MacBook Air here.

You can read our review of the 11-inch 2013 MacBook Air here and the review of the 13-inch 2013 MacBook Air here. We have a preview of the new 2014 MacBook Air here. We also have a comparison review of the 13in MacBook Air versus the 13in MacBook Pro.

We also share our 5 reasons to buy a MacBook Air and 5 reasons NOT to buy a MacBook Air. Read our 11in MacBook Air benchmarks

Watch our video where we compare the 2013 MacBook Air models:

Which MacBook Air: specs comparison

The new MacBook Air models look identical to the 2013 models, and indeed, the same as the 2012 MacBook Air models. On the inside the 2014 MacBook Air is only slightly different to the 2013 model, but both the 2013 and 2014 MacBook Air models are very different to the 2012 MacBook Airs - both offer Intel Haswell processors, Intel HD Graphics and PCIe flash storage. 

As with last year's model, aside from the screen size, the specs for the four MacBook Air machines are pretty similar - all four share the same processor running at the same clock speed and all feature the same graphics. The only choice other than size is how much storage you want: 128GB or 256GB with both options available for each laptop. 

In addition both the 11-inch and 13-inch versions of the 2014 MacBook Air laptops feature the same full-size, backlit keyboard, and both have a multi-touch trackpad (the one on the 13-inch is slightly larger) as the previous generations. Both feature two USB 3.0 slots and one Thunderbolt as they did previously. 

As before, only the 13-inch model has an SDXC card slot so if you are an avid photographer that may make the decision for you.

[Wondering whether to buy a MacBook or a Mac desktop? Find out if you should buy a Mac laptop or Mac desktop here.]

Which MacBook Air: 2012 versus 2013 versus 2014 MacBook Air models

In the case of 2012 generation MacBook Air specs the 11-inch model required a trade in. The 2012 entry-level model offered just 64GB storage for example and both 11in models had slower processors. The fact that the specs are now the same is great news for fans of the 11-inch MacBook Air because that model is as good as the 13-inch model. Indeed, the 2013 model was not only faster than the 2012 model, it was almost as fast as the 13-inch MacBook Air, according to our Speedmark tests. We expect that the new 2014 MacBook Air will prove even faster due to the slighlty faster processor in the new model.

In 2013 we were somewhat surprised that we found the 13-inch MacBook Air to be no faster than 2012's model - scoring the same Speedmark score. In fact in some of our tests the 2012 model actually beat the 13-inch 2013 model. There was a good reason for this, the Haswell processors are running at a slower clock speed than the previous machines - 1.3GHz compared to 2012's year’s 1.8GHz Ivy Bridge model. The new 1.4GHz processor in the 2014 MacBook Air should give the new MacBook Air a boost that should set it apart from the 2012 model.

Given that despite the slower clock speed the 2013 1.3GHz Haswell chip matched the old 1.8GHz Ivy Bridge when it came to our speed tests we expect that the new MacBook Air will prove even faster than the old 1.8GHz model. The reason for last year's boost was the new graphics and faster flash storage in the 2013 MacBook Air, compared to the previous generation. Apple said that the flash storage was 9 times faster than a traditional 5400-rpm notebook hard drive, and it still makes this claim with the 2014 model. Last year we found that a 6GB file transfer on the 13-inch model was 25 percent faster than 2012 year and on the 11-inch MacBook Air it was 50 percent faster than 2012's equivalent. 

We also found that the new Intel graphics sped things up 24 percent on the 2013 11-inch compared to 2012’s model.  You could also expect to see 8 percent higher frame rates in games like Portal 2.

Which MacBook Air: best storage and RAM options

As you can see, there is little difference when it comes to the speed and power of the 2013 versions of the 11-inch and 13-inch MacBook Airs and we expect the same to be true of the 2014 models. The differentiating option, other than the obvious (size), is storage. Choose between 128GB and 256GB on each model as standard, or pay an additional £240 for 512GB as a build to order option. We’d recommend that you save your money and spend it on external storage. You’ll get more for your money that way. 

The other decision will be over RAM. All the machines come with 4GB as standard but we’d recommend you boost that to 8GB for an additional £80 at time of purchase. Since these machines aren’t upgradable you may regret it in a few years time if you don’t max out your RAM now.  

Which MacBook Air: battery-life comparisons

Battery life was the big difference between the 2012 and 2013 MacBook Air models, this was because Haswell is less power hungry making a longer battery life possible. Apple claims that while battery life is still rated the same as on the 2013 MacBook Air, iTunes movie playback times now increase to 12 hours on the 2014 13-inch laptop and 9 hours on the 11-inch MacBook, adding up to two hours of playback time to the updated 2014 MacBook Air, according to the company's tests.

In 2013 our battery tests suggested slightly less than Apple's claimed 12 hours for the 13-inch, at 8 hours 18 minutes for the 13-inch, but that’s still 36 percent longer than 2012. 

Similarly last year Apple's 11-inch claimed a nine hour battery - while our tests suggest around 6 hours 6 minutes, but that was still double that of 2012’s. 

For many longer battery life will be at the top of their wish list when choosing a new laptop. Most of the laptop owners we know complain that they don’t get enough battery life out of their portable, and the popularity of the iPad with its 10-hour battery has lead many to start to expect the same of their laptop. 

If you want a laptop you can take on a long-haul flight with a battery to match then the 13-inch MacBook Air will be a great choice. If you have a slightly shorter flight and you’d prefer lighter hand-luggage then the 11-inch will be more than sufficient. 

Which MacBook Air: screen size versus weight

Battery life aside, the choice between the two identically speced models really is just a matter of screen size verses weight. Either you’re prepared to carry 270g of extra weight for a slightly larger screen, or you aren’t. We’ve been using the smaller MacBook Air for a week now and we’ll admit that the 11-inch screen wasn’t nearly as cramped as we expected and was a worthy tradeoff for being able to throw the laptop in a bag and carry it around without feeling weighed down. 

Alternatively the 13-inch may be the model for you. You may be swayed by the SD memory stick slot for example. At the end of the day it still only costs £100 more to upgrade to the bigger screen and that extra screen space may make all the difference. That said, you could always spend some of that £100 on an external monitor and plug your 11-inch MacBook Air into that. 

For some the decision may be between the 13-inch MacBook Air and the MacBook Pro with Retina display. The 13-inch Air has a native 1,440-x-900 screen resolution compared to the 2,560-by-1,600 resolution on the 13in MacBook Pro with Retina. As we discuss in this article about the difference between the MacBook Pro with Retina display and the MacBook Air, in 2013 there was only £150 price difference between the 13in Air and 13in Pro Retina. Now in 2014 the difference between the two models is £250 - which for some will be a significant reason to opt for the MacBook Air - afterall, you could add a separate screen to your purchase and be no worse off (although the screen wouldn't be Retina it woudl be bigger than 13-inches).

It's a matter of personal taste as to whether the 13in or 11in screen is best, we'd advise a visit to an Apple Store to try both out. Unfortunately you won't be able to put one in your backpack in order to judge how heavy it is.

MacBook Air and MacBook Pro compared

Which MacBook Air: iPad versus 11in iPad Air

Where in the case of the 13-inch MacBook Air there may be a decision to be made between choosing the Retina or Pro 13-inch versions, in the case of the 11-inch model there is no real equivalent in terms of laptop. Perhaps the only competition to the 11in MacBook Air, from Apple’s offering at least, is the iPad. You can buy a 128GB iPad Air for £739 (saving £110) and that has cellular connectivity so you can always be online.

Read all our news, reviews, features about the MacBook Air here.