To make matters simple, we've compared the Apple Watch Series 5 to the Series 3 here so you can see exactly what the differences and similarities are, whether you're looking to upgrade or take the smartwatch plunge.
For the avoidance of doubt, the Series 5 is very similar to the now-gone Series 4 with a few new features.
Apple Watch Series 5 vs Series 3: Design and display
- Series 3: 11.4mm thick, 5ATM waterproof, OLED Retina display with Force Touch
- Series 5: 10.7mm thick, 5ATM waterproof, LTPO OLED Always-On Retina display with Force Touch
- All straps compatible across all models
The Apple Watch Series 3 features a solid rectangular body with the Digital Crown and separate button on the right, along with a speaker and microphone on the left. It's swim-proof up to 50-metres and it features Ion-X glass on top of the display. The GPS and Cellular model is differentiated with a red accent on the Digital Crown.
The heart rate monitor is positioned on the underside of the watch body, along with the release buttons for switching out the straps and the second-generation OLED Retina display sits on top, two times brighter than the Series 1 at 1000nits. The GPS model has a composite back, while the GPS and Cellular model has a ceramic and sapphire crystal back.
The Apple Watch Series 5 sticks with a familiar design and same strap mechanism as the Apple Watch models that have gone before them, but Apple made a couple of changes with this model (as it did with Series 4).
Firstly, the Digital Crown on the Series 5 model (and Series 4) has an electrical heart rate sensor built into it, which is in addition to the optical heart rate sensor on the underside of the watch cases.
The Series 5 also has a much larger display with rounded edges, making full use of the space available and resulting in a bolder design. The 40mm Series 5 offers a 759sqmm2 display area compared to the 563sqmm2 on the 38mm Series 3, while the 44mm Series 5 has a 977sqmm2 display area compared to the 740sqmm2 of the 42mm Series 3.
The larger display ratio makes the Series 5 (and Series 4) look quite different from the Series 3 despite a similar design overall. In addition to the display increase, the Apple Watch Series 5 also offers an Always-On Retina display, which is the main differentiating factor between it and the old Series 4.
The Always-On display means you don't have to raise your wrist to wake the display up, with the screen always visible. A raise of the wrist or a tap on the display will brighten the Series 5 display instead.
Apple Watch Series 5 vs Series 3: Models
- Series 3: Aluminium only options, two colours, Nike+ model
- Series 5: Aluminium and stainless steel options (three colours), Titanium options (two colours), Ceramic option (one colour) Nike+ models and Hermès models
- GPS and GPS and Cellular options for Series 3 and Series 5
- Size options: 38mm/42mm (Series 3), 40mm/44mm (Series 5)
When the original Apple Watch launched, its case was available in aluminium, stainless steel and special materials like solid gold, all of which came in two size options of 38mm and 42mm.
The Series 3 then introduced a ceramic model, but this was discontinued when the Series 4 arrived. Ceramic is back on the Series 5 though, along with a new titanium option.
The Series 3 is now only available with an aluminium case, either silver or space grey, with a Sport Band. You can of course buy separate straps, but you won't be able to get the Series 3 in stainless steel or any other material.
The Series 3 comes in 38mm and 42mm size options, as well as in a choice of GPS only or GPS and Cellular. There is also a Space Grey aluminium Nike+ model available with a Anthracite and Black Nike Sport Band. The Nike+ model is also available in GPS and GPS and Cellular options.
The Series 5 has a lot more options available than the Series 3 and it comes in 40mm and 44mm sizes. Firstly, there is the standard Apple Watch Series 5, which comes in choice of three aluminium colours and nine standard Sport Band options. There are then stainless steel case options, also available in three colours, as well as various strap options from Sport Loop bands to the Milanese Loop and the Leather Loop. The titanium models come in two colour options with various straps and the ceramic model comes in one colour option with various strap options.
Aluminium models come in GPS or GPS and Cellular models, while stainless steel, titanium, ceramic and Hermès models are all GPS and Cellular as standard.
It's also possible to use Apple's Apple Watch Studio to pair up the Series 5 model you choose with the strap you want. Previously, you had to buy additional straps separately if you wanted a different strap to what the model you picked came with.
There are also Series 5 Nike+ models available, all with aluminium casings, and Series 5 Hermès models available, all of which have stainless steel casings (two colour options) and special Hermès straps.
While all the standard Series 5 models and the Nike+ models come in both case sizes though, some of the Hermès models only come in either 40mm or 44mm, not both.
Apple Watch Series 5 vs Series 3: Hardware
- Series 3: S3 processor, W2 wireless chip, Bluetooth 4.2
- Series 5: S4 processor, W3 wireless chip, electrical heart sensor, fall detection, built-in compass, Bluetooth 5.0
- Series 3/5: Barometric altimeter, ambient light sensor, built-in GPS, optical heart sensor, accelerometer, gyroscope, 802.11b/g/n 2.4GHz Wi-Fi, 18-hour battery life
The Apple Watch Series 3 has a dual-core processor called the S3 under its hood, coupled with a wireless chip called the W2. The GPS only model has 8GB of memory, while the GPS and Cellular model has 16GB of memory, as well as LTE connectivity. The LTE connectivity means you can make and receive calls and text messages, as well as perform all the tasks you'd want to on your Watch without your iPhone in range.
Both the GPS and GPS and Cellular Series 3 models offer Siri directly from the watch rather than transferring it to your iPhone, as they do on the Series 5.
The Apple Watch Series 5 has an upgraded processor that is claimed to be two times faster than the S3, called the S4. They also have the next generation wireless chip called the W3.
Many of the hardware features are the same as Series 3, including the barometric altimeter, built-in GPS and the optical heart rate sensor, but the and Series 5 does add a few extras.
They improve the accelerometer from up to 16 G-forces to up to 32 G-forces and they also add an electrical heart rate sensor to the Digital Crown, as we mentioned, which will allow users to take an ECG themselves.
The Series 5 also offers a built-in compass too, as well as international emergency calling.
Apple Watch Series 5 vs Series 3: Software
- All run WatchOS 6
- Extra features on Series 5
The Series 1, Series 2, Series 3, Series 4 and Series 5 all run WatchOS 6. The original Apple Watch does not support WatchOS 5 and it doesn't support WatchOS 6 either.
All generations, except the original Apple Watch, therefore all offer a similar experience, even if there are a few extra features on the Watch Series 4 and Series 5, like fall detection and the ECG function (US/UK/Europe only for now), as well as the Always-On Display and built-in compass on the Series 5.
With WatchOS 6, Apple's smartwatch offers a dedicated App Store, female health tracking, enhanced Siri, Activity trends and more. You can read all about WatchOS 6 in our separate feature.
Apple Watch Series 5 vs Series 3: Price
- Series 3: From $199/£199
- Series 5: From $399/£399
The Apple Watch Series 3 is the cheapest way to get your hands on Apple's smartwatch through Apple itself, with a starting price of $199/£199 for the GPS only model. The GPS and Cellular model starts at $299/£299, which is $100/£100 cheaper than the starting price for the Series 5.
The Apple Watch Series 5 with GPS only starts at $399/£399 for both the standard model and the Nike+ model. The Apple Watch Series 5 with GPS and Cellular starts at $499/£499 for the standard model or Nike+ model, but this increases to $699/£699 if you want a stainless steel model.
The Apple Watch Edition models (titanium and ceramic options) start at $799/£799, with the ceramic model costing $1399/£1399. The Hermès models start at $1249/£1249.
Apple Watch Series 5 vs Series 3: Conclusion
If you didn't invest in the original and you've decided the Apple Watch is now something you want, buying the Series 3 over the new Series 5 model will save you £200, but you miss out on some key features and your finish options are more limited.
The Apple Watch Series 5 not only adds a more advanced processor, but it offers a much bigger display that makes better use of the case size, an improved accelerometer, fall detection, Bluetooth 5.0, an electrical heart sensor, which allows users to measure their own ECG (US/UK/Europe-only for now), as well as an Always-On display and a built-in compass.
All the other features might remain the same, but for some, the new display design, improved processor and ECG functionality, Always-On display and built-in compass could be the five features you needed to take the smartwatch plunge. For others, the Series 3 will more than suffice.
In terms of upgrades, those with the original Apple Watch, Series 1 or Series 2 will see some worthwhile differences by switching to the Series 5, especially with the new display. Those with the Series 3 will also likely see a decent difference in the new model, but it might also be worth waiting until the Series 6 to see if sleep tracking appears, or a change up in design.
If you already have the Series 4 and you're wondering whether to upgrade to the Series 5, you don't need to this time around unless you really want that Always-On display function or the built-in compass.