The 2013 MacBook Air 13-inch looks exactly the same as last year's model. It features the same super-slim, lightweight design and if you are looking for a slim, lightweight laptop the MacBook Air is still the best around, although obviously it's smaller sibling is even lighter.

If you are trying to decide whether to go for an 11-inch and 13-inch MacBook it will all come down to how much screen you are willing to sacrifice for weight. Both feature the same full-size, backlit keyboard, and both have a large multi-touch trackpad. Both feature two USB 3.0 slots and one Thunderbolt. The 13-inch model is the only MacBook Air with an SDXC card slot, making it a better choice for photographers. There’s no DVD drive on either model, so you may want to invest in a separate Apple USB SuperDrive for £65.

There are four different machines available, but aside from screen size, the specs are pretty similar. In fact in our tests just one Speedmark point separated the 13-inch and 11-inch models in our tests and performance was practically identical. You can read our Sister title MacWorld's advice about Which MacBook Air to buy here.

This review focuses on the 13-inch MacBook Air.

Apple's 13-inch MacBook Air measures 32.5cm wide and 22.7cm deep and weighs 1.55kg. The screen's diameter is actually slightly larger than 13in at 13.3in from corner to corner.

There is one tiny external difference that may be useful to know if you want to make sure you are buying the newest model (some stores will be discounting the older model now so don't be taken in by marketing that looks like they have cut prices on the current model). The 2013 MacBook Air sports two tiny holes near the audio port. These tiny holes are microphones and the second mic is new to the 2013 MacBook Air. Having dual mics helps with noise cancellation, improving audio quality recorded using the new model.

The real changes between the 2012 and 2013 MacBook Air are under the hood, however. On the inside the 2013 MacBook Air features the new Intel Core Haswell processor, rather than the Ivy Bridge chip of last year.

Haswell processor benefits

The new Haswell processor requires less power than the Ivy Bridge processor found in last year's MacBook Air, as a result Apple has been able boost the battery life in the new model (more on battery life below).

The Haswell processors in the new MacBook Airs actually run at a slower clock speed than the Ivy Bridge processors found in the 2012 models. As a result, Macworld's tests show that the 2012 13-inch, 1.8GHz Ivy Bridge MacBook Air was faster than the 2013 13-inch, 1.3GHz Haswell MacBook Air in 8 of 14 tests. The 2012 model beat the 2013 model in the following tests: folder compression, iMovie, iPhoto, Photoshop, Aperture and MathematicaMark 7.

However, the faster graphics and faster flash storage in the newer MacBook Air was enough to result in the two generations earning identical Speedmark 8 scores.

Note that the difference between the 2012 and 2013 11-inch model is more marked than the difference between the 13-inch models, with the 11-inch MacBook Air jumping 9 percent in its Speedmark score.

Some may suggest that the fact that the new 1.3GHz Haswell chip matches the old 1.8GHz Ivy Bridge proves the enhancement in the new processor.

If you want a faster processor you can configure your perfect machine at the point of sale (it can't be updated after you have bought it). For an extra £130, Apple will swap out the dual-core 1.3GHz Core i5 processor for a dual-core 1.7GHz Core i7 with Hyper Threading and with Turbo Boost speeds of up to 3.3GHz. We are yet to test this build to order model but it sounds like it might be worth the money to upgrade.

MacBook Air all-day battery

The big news is the longer battery life that the Haswell processor makes possible, and for many longer battery life will be at the top of their wish list. 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.

With the new MacBook Air Apple has aimed its sights on this problem.

Apple claims that the 13-inch MacBook Air offers battery life that will last a full working day. That's 12-hours for the new MacBook Air compared to seven hours for last year's machine. Does the MacBook Air match Apple's battery life claims?

The testing in the Macworld Lab didn't quite replicate Apple's battery life claims, but we run slightly different tests to assess battery life. Macworld Lab ran two tests to compare this year's new models with last year’s MacBook Air models and a 2013 13-inch Retina MacBook Pro. Based on our tests we can confidently say that the new MacBook Air’s battery life is much, much better than before.

In our tests the new 13-inch standard configuration MacBook Air lasted 8 hours and 18 minutes, that's 36 percent longer than the new 11-inch MacBook Air, and 65 percent longer than last year’s 13-inch MacBook Air.

Compared to the 2013 13-inch Retina MacBook Pro, the 13-inch MacBook Air lasted 75 percent longer. Read Macworld.com's article for fuller battery-test results.

Our sister title PC Advisor's battery tests found that the new MacBook Air models had battery life that was even better than that claimed by Apple. According to PCA's MobileMark 2007 Productivity Test the MacBook Air ran for 13 hours and 57 minutes.

Is there enough storage in the MacBook Air?

The MacBook Air is available with a choice of 128GB or 256GB Flash Storage. Some people will have no problem fitting their necessary onboard data within the 128GB capacity of the two lower-end models. Others will be concerned that even 256GB isn't enough storage for their needs. All is not lost, however: It is possible to configure a 512GB Flash Storage option when you buy the MacBook Air for an additional £240. The MacBook Air cannot be updated at a later date so you need to decide whether to fork out the extra for the additional storage when you buy the machine.

However this isn't your only option for extra storage, you may be happy to plug your MacBook Air into an external drive - you could get a pretty decent NAS drive for the extra £240 you would be paying the extra 256GB of Flash Storage Apple would build into your system. Of course a 1TB hard drive will not be as speedy as your on-board Flash Storage. Alternatively you could back your files up to the cloud, which is a handy option if you want to be able to access them from anywhere. 

Fast Flash storage

Concerns about whether there is enough storage for your needs may fade into obscurity once you realise the benefits of Flash Storage – also referred to as SSD.

The 2013 MacBook Air models offer much faster flash storage than any other Mac. Apple claims this next-generation PCIe flash storage is up to 9x faster than a traditional 5400-rpm notebook hard drive and up to 45 per cent faster than the flash storage in the previous-generation MacBook Air.

Our tests showed that the flash storage inside the new MacBook Air makes it possible for the new models to achieve better or identical speedmark 8 results despite the new Haswell processor running at a slower clock speed.

The 2013 13-inch MacBook Air transferred 6GB of files and folders 25 percent faster than last years model did.

The faster flash also helps to reduce startup times. The new 13-inch Air took around 14 seconds to start up, versus 18 seconds for last year’s model.

When it comes to waking from sleep, Apple says that the MacBook Air will wake up in one second.

Not enough RAM

One sure fire way to speed up a computer is to give it more RAM and one area where many will find the MacBook Air lacking is RAM. There is just 4GB of 1600MHz LPDDR memory as standard on all models and for some this will not be adequate for their needs. Luckily you can boost this to 8GB for an extra £80. If you can afford to we strongly recommend that you purchase the extra RAM as you won't be able to add it later and a few years down the road your are bound to be wishing you had.

Note that Apple’s other non-upgradable Macs, like the Retina MacBook Pro and 21.5-inch iMacs have 8GB of RAM as standard so in some areas it's already considered the norm.