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1 October 2020

Which Apple Watch should you buy?

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

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 5, 4 and 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. We take a look at the latest smartwatches from Apple, from the Series 1 through to the Series 5. 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%. Our guide to the most accurate fitness trackers and smartwatches reveals how each model scores on steps, distance and heart-rate.

You can also see how Apple fares in our reviews of the best smartwatches.

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.

Which Apple watch is best?

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Best Buy

This smartwatch packs in a tremendous range of smart, fitness and health features, yet it’s slimmer than its predecessors. The only thing we didn’t like about this watch was the short battery life, which effectively ties you in to charging it each day.

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Best Buy

This impressive smartwatch is available in two screen sizes, so you can pick the one to fit the size of your wrist. You get 16GB of storage to help you manage your music, photos and apps. It really shines when it comes to health and fitness, capable of tracking activities including rowing, running, cycling, hiking and even yoga.

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Best Buy

It’s available in two screen sizes, 38mm and 42mm, so you can pick the one to fit the size of your wrist. It’s available with an aluminium bezel and range of colours. In terms of smart features and notifications, there isn't much this watch can't do, and there’s a heart-rate tracker and GPS.

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Best Buy

This Apple Watch is a proven Best Buy. It has an always-on OLED touchscreen and plenty of smart features, including the ability to make and receive phone calls and get calendar alerts. A refreshed App Store lets you download watch apps straight to your wrist.

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Best Buy

Designed to give you greater freedom from your smartphone, this smartwatch is packed with fitness and smart features, including 4G connectivity and built-in GPS. It's available in two screen sizes - 38mm and 42mm - so you can pick the size to suit your wrist. This isn't the most accurate wearable we've tested, but it's still good at tracking fitness metrics precisely.

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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 3 GPS, Series 3 GPS + Cellular, Series 5 and Series 5 + Cellular. 

Apple Watches range in price from just under £200 for a Series 3 with an aluminium case and a sports band, right up to £1,500 for a designer Hermès version of the Series 5. 

The Apple Watch Series 5 with GPS starts at £399. The Apple Watch Series 5 with cellular (restricted to EE, O2 and Vodaphone in the UK) starts at £499. 

The original Apple Watch, Apple Watch Sport, Series 1, Series 2 and Series 4 aren’t available to buy from Apple anymore - the Series 4 was discontinued when the Series 5 was launched. But you may be able to pick up a second-hand one on the cheap. 

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. Find out what sets them apart in our tough tests, or read on to see the different benefits each version of the Apple Watch has to offer.


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 2019, Apple released a new version of its operating system – watchOS 6. This comes pre-installed on the Apple Watch 5. 

In October 2019, Apple released an update, watchOS 6.1. It's compatible with the Apple Watch 4, 3, 2 and 1, but not the original Apple Watch. 

Interesting new features of watchOS 6 include:

  • Access to the App Store on the watch itself - in the past, you had to download apps to your iPhone for use on your watch, but now you can do so from the watch itself, using Scribble or Siri.
  • New apps - including Apple Books, for listening to audiobooks through your Bluetooth headphones, Voice Memos, for note-making, and an official Apple calculator app (third party calculator apps were available before). You'll be able to delete any of these apps if you don't find them useful; in the past, only third-party apps could be deleted.
  • Noise notifications to protect your hearing health - your watch will alert you if the sound level over three minutes reaches a chosen decibel threshold. Of course, data privacy is a huge concern here, but Apple says that this feature, although it uses the microphone, doesn't record any sounds. This feature is only available with Series 4 and 5. 
  • New watch faces - the Series 4 already introduced some cool new watch faces, including moving fire, water and vapour watch faces and a rainbow-coloured Pride watch face. The new watchOS introduces a couple more - the 'Modular Compact', 'Solar Dial', 'California', 'Gradient' and 'Numerals' faces.


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, Apple 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. 

The Series 5 has the same larger display area as the Series 4. Whereas there was no always-on screen option with the Series 4, there is with the Series 5. 

The Apple Watch 5, like the Apple Watch 4, is available in two sizes: 40mm and 44mm. Previous versions of the watch came in 38mm and 42mm sizes. The Series 5 and the Series 4 also departs from the norm in that the digital crown gives haptic feedback (small vibrations) for what Apple calls a more 'precise, mechanical feel'.

For the Series 5, you can choose from a wider range of case materials (aluminium, titanium, stainless steel and ceramic) and also finishes (grey, black, silver, white, titanium and gold) than previous versions. Like the Series 4, it comes in 40mm and 44mm case sizes, and, if you already own an Apple Watch band, you'll be able to use that with it. 

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 was dropped for the Series 4, which was 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 3, 4 and 5 come with a variety of strap options, including rubber, leather or stainless steel link. The Series 1 can only be bought with a rubber strap.


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 had a new dual core 64-bit processor for (Apple claims) double the performance, and this has been updated again for the Series 5. 

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, Series 4 and Series 5 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 (so water resistant to up to 50 metres in depth for 10 minutes). The Apple Watch Series 3, Series 4 and Series 5 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

What's new with the Series 4 and Series 5 Apple Watches?

The Series 4 was a much bigger step forwards than the Series 5. Exciting new features for the Series 4 included three new FDA-approved heart monitors. The Series 4 and Series 5 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.

The Series 4 and 5 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 came with a redesigned speaker, so your phone calls should be clearer and your Siri requests more accurate. Other updates for the Series 4 included:

  • 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 above).

One thing that hasn't improved with the Series 4 or Series 5 is battery life - that's still 18 hours. Granted, the Apple Watch is 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. 

We've taken a first look at the Series 5, and we'll come back with more detail when we've put it through our full testing. Read our Apple Watch Series 5 first look review to find out what we thought of it - and whether it's worth upgrading if you already own a Series 4. 

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