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Which Apple Watch should you buy?

By Christina Woodger

Confused by the number of Apple Watch versions available? We explain the differences and reveal which came out on top in our tests.

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Apple is the leading name in the smartwatches market. An Apple Watch puts your phone’s screen on your wrist, so you can receive texts, calls, emails and calendar alerts with your phone firmly in your pocket. Or even, as with the Apple Watch Series 4 and Apple Watch Series 3 LTE, while your iPhone is safely at home. While all models look very similar, we’ve found that they aren’t all created quite the same.

Processor, price and features – these are just some of the differences between Apple Watch devices. In the table below, we take a look at the latest smartwatches from Apple, from the Series 1 through to the Series 4. We’ve found models that track steps without error, but we’ve also found one Apple Watch version that overstated calorie-burn by almost 50%. If you just want to read the full reviews, head over to our Apple Watch reviews.

We compare the notification and messaging features of every Apple Watch, as well as how quickly it completes tasks, to help you pick the right one for you. To check the accuracy of the fitness tracking, our test participants walk on a calibrated treadmill at 4.8km/h for 10 minutes and run at 9-10km/h for 10 minutes. They also complete a routine of daily tasks, such as loading and unloading the dishwasher, and carrying the shopping. To find out more about the challenges all wearables face in our labs, see how we test smartwatches.

Only logged-in Which? members can view the full Apple Watch results in the table below. If you’re not yet a member, join Which? to get instant access.

Apple smartwatches


Newer models have since been launched, bringing with them some big new features. You won’t be disappointed with this one, though: it’s still our joint-best smartwatch, and it’s packed with great smart and fitness features. It’s a tiny bit cheaper now, too.


The joint best of the Apple Watches, and of all the smartwatches we’ve tested. It has all the smart, fitness and health features you’d expect from an Apple – plus some unexpected ones, such as the ability to detect falls and take ECG (electrocardiogram) readings.


There’s a lot to love about this watch, including its excellent display, sophisticated heart-rate monitor and comprehensive range of features. It’s one of our highest rated Best Buys in fact, and well worth a look.

Not found the product for you? Browse all of our smartwatch reviews.

How much will an Apple Watch cost? 

The price you pay will depend on which Apple Watch options you choose, including the size of the screen, and the material of the band and casing. Apple has also partnered with other brands, such as Nike, and designers to offer additional options.

The current range includes the Apple Watch Series 1, Series 3 GPS, Series 3 GPS + Cellular and Series 4. They range in price from just under £250 for a 38mm Series 1 with an aluminium case and rubber sports band, right up to £1,500-plus for a designer Hermès version. 

The Apple Watch Series 4 with GPS starts at £399. The Apple Watch Series 4 with cellular (restricted to EE and Vodaphone in the UK) starts at £499. Apple also dropped the price of its Series 3 when the Series 4 was announced, so it now starts at £279 for the 38mm option. 

The original Apple Watch and Apple Watch Sport aren’t available to buy via Apple, but you may be able to pick up a second-hand one on the cheap. You might also see the Series 2 in some retailers, although this was officially discontinued by Apple in September 2017. 

Choosing the best Apple Watch

All of the models in the Apple Watch range are compatible with iOS devices, such as your iPhone and iPad, and offer similar features. The current range includes the Apple Watch Series 1, Series 3 GPS, Series 3 GPS + Cellular and Series 4. So what sets them apart, and what should you look for?


All Apple Watches run watchOS, Apple's operating system. This is designed to work exclusively with iOS devices and so can’t be used with Android or Windows. Check out our smartwatch reviews for devices that are compatible with other operating systems. 

WatchOS is a touch-based interface that offers the gamut of smart features. You can read and respond to texts and emails, answer and make phone calls, and get social media notifications. You can also use the watch to craft social media posts, such as tweets, from scratch, and make contactless payments via Apple Pay. You can use the voice-command feature courtesy of Siri.

In September 2018, Apple released the next version of the operating system – watchOS 5. The Series 4 will have this pre-installed. Older models – apart from the original Apple Watch – can be updated with the latest OS version, too. 

Interesting new features of watchOS 5 include:

  • new watch faces, including moving fire, water and vapour watch faces and a rainbow-coloured Pride watch face. It still doesn't support third-party watch faces. 
  • the ability to view basic web content from your watch face - opening links that people send you, for example - via WebKit
  • a retro-sounding Walkie Talkie feature for quickly contacting friends and family without making a full phone call
  • automatic workout tracking when the watch thinks you're stopping or starting an activity
  • fitness tracking modes for yoga and hiking, in addition to the existing fitness modes
  • improvements to the running mode, including cadence tracking
  • Apple podcasts, for listening to your favourite shows while out and about
  • raise-to-speak functions for Siri, meaning you don't need to say 'Hey Siri' anymore before giving instructions (although you can leave this setting toggled on if you want to)
  • a competition mode for challenging Apple-using friends to week-long fitness competitions (pictured below).


All Apple Watches look similar, with a rectangular face, touchscreen display and circular button on the side for scrolling through menus and notifications. With the Series 4, however, Apple has stretched out the screen to the edge of the watch, making it 30% bigger than on the Series 3 and giving you more information at a glance. There's still no always-on screen option, though. 

The Apple Watch 4 will be available in 40mm and 44mm. Previous versions came in 38mm and 42mm. The Series 4 also departs from the norm in that the digital crown now gives haptic feedback (small vibrations) for what Apple calls a more 'precise, mechanical feel'.

The Series 1 comes with an Ion-X glass screen, while you can pick from Ion-X or the even more hard-wearing Sapphire Crystal for the Series 3. For the casing, you can choose from aluminium or stainless steel. There’s also a pricey ceramic option available for the Series 3 GPS + Cellular, which costs more than £1,200. This seems to have been dropped for the Series 4, which is available in stainless steel or aluminium. The aluminium models come in silver, gold and grey, and the stainless steel options come in space black, gold and 'polished'. The Series 4 does have a black ceramic and sapphire crystal back, designed to allow radio waves to pass through the front and back more easily for better cellular service. 

The Series 1 can only be bought with a rubber strap, which is good if you plan to exercise wearing your smartwatch as it will be easy to keep clean. The Series 3 comes with a variety of strap options, including rubber, leather or stainless steel link. For the Series 4, you can also choose from a range of new looks and colours, and even match your band to your iPhone case if you're so inclined. Again, there are special edition bands from Nike (with reflective yarn for running when it’s dark) and Hermès. Or you can keep using your existing bands, so they won't go to waste. 


All Apple Watches use an on-board processor. The original models have an S1 chip, while the Series 1 models have an updated S1P dual-core processor. The Series 3 is equipped with an S3 processor, which is more powerful and includes on-chip GPS functionality. The Series 4 has a new dual core 64-bit processor for (Apple claims) double the performance. 

Built-in GPS

Built-in GPS lets you track your routes without relying on your smartphone, so you can leave your mobile at home when heading out for a run. It’s available on the Series 3 and Series 4 models. 


The, now discontinued, Watch Series 2 was the first range of smartwatches from Apple to be made water-resistant, with a rating of 5ATM. The Apple Watch Series 3 and Series 4 have followed suit. This means they're fine to wear while showering or swimming, even in open water, but won’t be suitable for watersports or diving.

It’s currently impossible to seal a speaker, because it needs air to produce sound, but Apple has got round this by creating a speaker that lets water in and then uses sound vibrations to eject it back out. We checked the waterproofing claims for the Series 3 in our labs – find out if it passed, and if it’s a good option for keen swimmers, by diving into our full review. We've taken a first look at the Series 4, and we'll come back with more detail when we've put it through our full testing. 

What else is new with the Apple Watch Series 4?

Other exciting new features of the Series 4 include three new FDA-approved heart monitors. The Series 4 can:

  •  notify you if your heart rate is too low (the Series 3 notified you if it was too high)
  •  detect atrial fibrillation – irregular heart rhythms. Apple is being careful not to say that it definitely will detect this, mind you - but it could do. 
  • take ECG (electrocardiogram) readings which you can share with your doctor. Unfortunately this isn't available in the UK yet - we'll update you when we know more about when it will be. 

The Series 4 can also detect if you've fallen over and call 999 on your behalf if you've been immobile for a minute. The cellular version will do this even if you're not near your phone. 

And the Series 4 comes with a redesigned speaker, so your phone calls should be clearer and your Siri requests more accurate.

One thing that hasn't improved with the Series 4 is battery life - that's still 18 hours. Granted, it's a hard-working little device that's going to eat a lot of battery. But it's still a pain to keep having to charge it so often. 


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