Apple Watch SE isn't as cheap as the Series 3. So how do you decide which to buy?

Apple's two latest smartwatches include the affordable $279 Apple Watch SE (£269, AU$429) and the flagship $399 Apple Watch Series 6 (£379, AU$599). Both wearables run WatchOS 7, but the Watch SE has fewer features than the Series 6, including a less advanced S5 chipset. (Check out our roundup of the best Apple Watch deals too, because prices are fluctuating.)

Despite its lower price, however, the Watch SE isn't the cheapest wearable you can buy new from Apple. Its own Apple Watch Series 3, which launched in 2017, currently goes for $199 (£199, AU$399).

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Because the Watch Series 3 is three years older, it obviously isn't as high-powered and robust as the Watch SE. But it still packs a lot of features and you may prefer it over the Watch SE if you take into account how much money you'll save. Read on to learn more about their differences and see which one is right for you.

Read more: Apple Watch Series 6 vs. SE: What's the difference between them anyway?

Apple Watch SE $279 at Apple

Apple Watch Series 6 $399 at Apple

Apple Watch Series 3 $199 at Apple

Design: Watch SE is bigger and sharper

From afar, the Watch SE and Watch Series 3 look similar. They each come in two different sizes, are made of aluminum and are water resistant. But the former has a screen that's sharper and 30% bigger, or by a little less than a tenth of an inch (2mm) in both of its size variants. Apple's two new watchbands, the Solo and Braided loops, accommodate the larger sizes, so they won't fit the Series 3. The Watch SE's digital crown provides haptic feedback as well, and it comes in one more gold color option in addition to the standard silver and gray.

Note that neither watches have an always-on display. Originally introduced in the Watch Series 5 last year, it means that the screen is constantly on and you don't need to raise your wrist or tap the screen to look at the time or check for notifications. Of Apple's new watches, only the Watch Series 6 has this feature.

Hardware: Watch SE is twice as fast

When it first launched, Apple sold a model of the Watch Series 3 that had cellular connectivity. But the company doesn't sell those variants anymore and if you want one, you'll have to get it refurbished and from a third-party seller. As the newer device, Apple stocks both versions of the Watch SE. Cellular models are more expensive than the base Wi-Fi only watches, but having LTE allows you to use the device without tethering to a phone or a Wi-Fi network. This is useful when you want to leave your handset behind during a workout, but don't want to lose key functions like making calls (including international emergency calls) or connecting to apps.

The Watch SE is faster too. Apple said its S5 dual-core processor is twice as fast than the Watch Series 3's S3 chipset. For wirelessly connecting to devices, like the iPhone, the Watch SE uses the newer W3 chip and Bluetooth 5.0. The Series 3, on the other hand, uses the preceding W2 chip and Bluetooth 4.2. That means connecting to other phones on the Watch SE should be smoother and more stable. 

Both phones have altimeters, which measure your altitude and elevation. Because the Watch SE's altimeter is always on, however, its elevation readings are done in real-time. The newer watch also has a compass and four times more memory (32GB compared to the Watch Series 3's 8GB).

As for the battery, we weren't able to test the Watch SE's battery life yet. But back when we were reviewing the Watch Series 3, battery life was unimpressive. Because Apple said that both devices have the same battery life -- about 18 hours -- we expect more of the same underwhelming performance. But again, we'll have to get our hands on the watch to know for sure.

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Software features: Watch SE monitors for falls and loud noises

The Watch SE runs WatchOS 7, Apple's latest smartwatch software, right out of the box. Though the Watch Series 3 can download the update, not all of Watch OS 7's features will be available on the older wearable. That includes Family Setup, which lets you pair your iPhone to someone else's Apple Watch, be it a family member like a young child or an elderly adult. You can then apply controls, like limiting contacts and app downloads, or automatic location tracking.

The Watch SE also has other features that aren't new to Watch OS 7, but were available after the launch of the Watch Series 3. That includes fall detection and noise level monitoring, so if those are important to you, go with the Watch SE.

Lastly, if you're a runner, Apple will sell a Nike version of the Watch SE, which has the Nike Run Club app preloaded and comes with customizable watch complications to gather, analyze and share data from your runs.

The Apple Watch Series 3, dunked, sweated and tested

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