While the new Series 3 Apple Watch looks nigh-identical to its older models, it packs a ton of added functionality into those 38mm and 42mm casings.

The 38mm and 42mm Series 3 feature the following:

  • OLED 1000-nit Retina display with Force Touch
  • An S3 dual-core processor for a 1.7x faster speed bump that puts the Series 2 to shame
  • built-in GPS and GLONASS
  • Barometric altimeter for tracking stair-climbing and elevation gains
  • Water resistance (up to 50 meters)
  • Siri voice response
  • Wi-Fi and Bluetooth 4.2
  • Apple's W2 wireless chip for easy pairing to your iPhone and wireless accessories
  • Up to 18 hours battery life, depending on tasks

But for all their similarities, the Series 3 watches come in two configurations: GPS, and GPS + Cellular. Here's how the two of them differ.

Phone compatibility

The GPS-only Series 3 will work with any iPhone made after the 5s, like the Series 0, 1, and 2; in contrast, the Series 3 requires an iPhone 6 or later (yes, iPhone SE fans, this includes you).


This is the big one: The GPS + Cellular Apple Watch comes with LTE connectivity, which allows you to piggyback off your current carrier plan (for an additional monthly fee, usually around $10) and get internet and phone connectivity even when your iPhone is far away.

How your cellular carrier is handling the Apple Watch Series 3

If you want to enable LTE, you will need to be on the same carrier as your iPhone (so as to use the same phone number), but it's currently unknown whether you'll have to do this as an add-on to that plan or a separate plan with the same carrier.

The Series 3's LTE coverage lets you do anything solo on the Apple Watch that you can do when tied to your iPhone's data. That includes placing calls, receiving messages, using Siri, navigating via Maps, playing with third-party apps, and just about anything else.

Some information we've received is that certain carriers will allow you to receive SMS messages on your Apple Watch Series 3 without your iPhone, but won't let you send them. We're looking into this.

Siri is particularly impressive, responding practically instantaneously during our hands-on tests, but if the freedom of moving about with your watch without an iPhone appeals to you, the Cellular option is a huge benefit.

Apple Music streaming

While it won't launch when the Series 3 ships, the GPS + Cellular watch will gain support for Apple Music streaming in October — and it looks like it will be the only watch in Apple's lineup that can do so. We have a query in to Apple to confirm that this is a Series 3 GPS + Cellular exclusive, but I suspect it might have to do with the next bullet point on this list: storage size.

Storage Size

The GPS + Cellular Series 3 has double the storage capacity: 16GB to the GPS-only's 8GB. While we don't have an official answer from Apple as to why, I'm guessing it has to do with the watch's impending Apple Music streaming feature: Apple Music needs a certain amount of cached storage to stream, and if the company additionally plans to allow users to locally download playlists from the streaming catalog, the extra space is necessary.

Front Casings and Style

Like the gap between Series 1 and Series 2, the GPS-only Series 3 is limited to just aluminum Sport and Nike+ casings (silver, gold, or space grey) with their Ion-X glass screen. In contrast, the GPS + Cellular Watch retains the higher-end casings formerly present with the Series 2 in addition to the aluminum Sport and Nike+ casings. This includes options like stainless steel, white and grey ceramic, and Hermès steel.

The pricing on these has risen $50 over their Series 2 counterparts: $599 for steel, $1149 for Hermès, and $1299 for ceramic. I know a lot of folks are disappointed not to have steel as an option — especially those who can't yet get the Cellular Apple Watch in their country — but Apple likely doesn't want to sell their higher-end watches at a discount or with subpar features.

Also worth noting when it comes to style: All Series 3 GPS + Cellular watches have a red dot on the Digital Crown. Why? Well, there's always my theory…

Rear Casing

This is a big change from Series 2, and one that honestly leaves me a bit befuddled: The Series 3 GPS + Cellular watch is once again the only watch to receive a ceramic back cover, with the GPS-only watch using a composite back. Apple's original Series 0 Apple Watch only offered ceramic back covers for its steel and Edition watches, but the Series 2 moved so that all models — aluminum, steel, and ceramic — used ceramic backs.

Now, with the Series 3, there's a distinct division: All GPS + Cellular models (aluminum, steel, or ceramic) will receive a ceramic back, but the Series 3 GPS-only aluminum watches are reduced to a composite covering — much like the Series 1, which also sports a composite back.

It's a weird move for a device that's otherwise very similar, but it may help Apple keep prices low: The GPS-only Series 3's starting price is $329, a $20 discount off the $349 starting price of the Series 2.

Battery Life

This is a question I've received multiple times on Twitter, and it's a good one: Will the Series 3 GPS + Cellular have worse battery life than the Series 3 GPS-only Apple Watch?

The answer is: Yeah, probably — but only if you're using GPS + Cellular. Apple's own battery tests peg both watches at an 18-hour average, with specifics highlighted below:

All-day battery life is based on 18 hours with the following use: 90 time checks, 90 notifications, 45 minutes of app use, and a 30-minute workout with music playback from Apple Watch via Bluetooth, over the course of 18 hours.

Apple Watch Series 3 (GPS) usage includes connection to iPhone via Bluetooth during the entire 18-hour test. Apple Watch Series 3 (GPS + Cellular) usage includes a total of 4 hours of LTE connection and 14 hours of connection to iPhone via Bluetooth over the course of 18 hours.

While Apple doesn't note which watch configuration it used for these tests (38mm or 42mm), it did peg the Cellular watch at 18 hours' with 4 hours of LTE and 14 hours of iPhone connectivity — about what the average person might use in a given day.

Specific battery tests, however, are far less forgiving. Here's how the Series 3 fared in Apple's single-task tests:

  • Talk: 3 hours connected to iPhone, 1 hour w/ Cellular
  • Audio: 10 hours w/ Bluetooth (Apple Music streaming not tested)
  • Workout: 10 hours w/ iPhone, 5 hours using just GPS, 4 hours using GPS + Cellular

And herein lies the downside of a GPS + Cellular-enabled watch: In choosing to pursue connectivity over battery life, Apple still doesn't quite have the battery numbers to make long-distance runners (like ultra-marathoners) happy if they're using GPS, let alone GPS + Cellular.

We'll be doing extensive battery testing for our Series 3 review to try and confirm and expound on these numbers, so stay tuned.


Both watches will be available for pre-order on the 15th and shipping on the 22nd, but the GPS + Cellular watch (and its various casing permutations) will only ship to 10 countries at launch.

This includes:

  • The U.S.: AT&T, Sprint, T-Mobile, and Verizon
  • The U.K.: EE
  • Canada: Bell (Telus later in 2017)
  • Puerto Rico: AT&T, Sprint, and T-Mobile
  • Australia: Optus and Telstra (Vodafone later in 2017)
  • France: Orange
  • Germany: Telekom
  • Japan: NTT DOCOMO, au, SoftBank
  • China: China Unicom only for Guangdong, Henan, Hunan, Shanghai, and Tianjin (China Mobile and China Telecom later this year)
  • Switzerland: None at launch (Sunrise and Swisscom both later in 2017)

Because you can't use a watch on a different carrier than what you currently use for your iPhone, this will drastically limit the number of GPS + Cellular buyers at launch to these countries and carriers.

We're currently looking into whether you can buy a Apple Watch Series 3 GPS + Cellular in one of these countries and use it in your home country until your network offers service, and will report back when we know more.


The final metric that separates these two devices is price: The GPS-only Series 3 starts at $329 for a 38mm aluminum casing, while the GPS + Cellular Series 3 starts at $399, a $70 upcharge. If you want cellular service, the nicer casings, storage, and Apple Music, that price might well be worth it. If you can't, you might want to skip out this year.

Which watch is worth it?

What do you think, iMore? Will you be picking up a GPS + Cellular Series 3 next week, or just GPS? Or no Series 3 at all? Let us know below.