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, and the question of whether that would be a good buy in comparison with the newer models.

An important aside: Apple may soon update the MacBook Air - 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.

Further complicating the MacBook Air purchase decision: there is less difference in price between the MacBook Air and the MacBook Pro with Retina display now, and just £150 difference between the 13in models, read more about the difference between the Air and Pro here. If you are on the market for a new laptop it may be worth paying a few pounds more and getting the MacBook Pro with Retina display.

When Apple launched its 2013 MacBook Air last June the decision of which model to buy become harder than ever. In the past it was a simple sacrifice or power and screen size for portability, but the 2013 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.  

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 also have a comparison review of the 13in MacBook Air versus the 13in MacBook Pro.

Which MacBook Air: specs comparison

The new MacBook Air models look identical to 2012’s models, but on the inside they’re very different to the 2012 MacBook Airs, boasting the latest Intel Haswell processor, new Intel HD Graphics and PCIe flash storage. 

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 2013 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). Both feature two USB 3.0 slots and one Thunderbolt. 

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

Which MacBook Air: 2012 versus 2013 models

In the case of previous generation MacBook Air specs the 11-inch model always required more of 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 not only faster than the 2012 model, it’s almost as fast as the 13-inch MacBook Air, according to our Speedmark tests. 

Somewhat surprising is the fact 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’s a good reason for this, the new 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. 

However, it’s key that despite the slower clock speed the new 1.3GHz Haswell chip matched the old 1.8GHz Ivy Bridge when it came to our speed tests. This is thanks to the new graphics and faster flash storage in the new MacBook Air, which Apple says is 9 times faster than a traditional 5400-rpm notebook hard drive, 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 11-inch compared to 2012’s model.  You can 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. 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 is the big difference between the two MacBook Air models, this is because Haswell is less power hungry making a longer battery life possible.

Battery life is as much as 12-hours in the case of the 13-inch model, according to Apple. Our battery tests suggested slightly less at 8 hours 18 minutes for the 13-inch, but that’s still 36 percent longer than 2012. 

Apple says that the 11-inch offers a nine hour battery - our tests suggest around 6 hours 6 minutes, which is almost 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 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, there is now only £150 price difference between the 13in Air and 13in Pro Retina.

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.

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.