Apple Watch vs. Samsung Galaxy Watch: Which should you buy?

The Apple Watch Series 4 and Samsung Galaxy Watch are both excellent smartwatches that can do everything from fitness tracking to mirroring notifications on your phone. But which one should you buy?

We tested the Apple Watch Series 4 and Galaxy Watch side-by-side to see which one best fit our needs. For this test, we wore the smaller versions of each: 40mm and 42mm respectively. If you're looking for the latest Apple Watch 5 vs. Galaxy Watch Active 2 you can find our comparison here.

Design and durability

The obvious difference between these two watches is their shape: The Apple Watch has a square face, while the Galaxy Watch is round.

We like the eye-catching round screen of the Galaxy Watch because it more closely resembles an analog watch. There's also a rotating bezel around the screen to change settings or navigate through notifications. It has a really pleasing tactile sensation that "clicks" each time you turn it, unlike the digital crown on the Apple Watch that only has a limited amount of haptic feedback. The Galaxy Watch bezel feels like a more natural way to interact with the watch than the tiny crown.

But the Galaxy Watch is thicker than the Apple Watch, which means it's more prone to get caught on coat sleeves. The extra thickness and weight was most noticeable during workouts, as it didn't sit snugly on my wrist and was heavier, though those with larger wrists may not have the same experience.

The Galaxy Watch comes in a black or silver finish in both sizes, plus a rose gold option for the 42mm version. The Apple Watch has gold, space gray or silver options for all sizes.

If you like to change up your look by changing the straps, there are fewer official straps for the Galaxy Watch than the Apple Watch -- but many third-party straps are available for both.

Both screens are easy to see in outdoor situations. The Super AMOLED screen on the Galaxy Watch may look slightly brighter when looking at it in direct sunlight, but it's also less responsive when you raise your wrist to wake it up.

Winner: Galaxy Watch

Smartwatch features are neck and neck

The Galaxy Watch is compatible with both Android and iOS, while the Apple Watch can only be used with an iPhone.

Here's what both of them can do:

The cheapest Galaxy Watch is currently $280 in the US (£279, AU$549). Add another $70 for LTE.

The cheapest Apple Watch is $399 (£399, AU$599) and you have to pay $100 more for LTE.

Although the Samsung is compatible with both iOS and Android, there are some limitations to what you can do if you connect it to an iPhone. For example, you won't be able to respond to messages if the Galaxy Watch is tied to an Apple phone.

It's easy to see notifications on both, but the rotating bezel makes it super simple to keep track of notifications on the Galaxy Watch -- just swipe the screen and swivel the bezel. The Galaxy Watch is also the only one that lets you keep the display on at all times if you want to be able to see the time.

Although both watches limit what their voice assistants can do compared to the phone versions, Siri is much faster and more responsive than Bixby.

Winner: Apple Watch

Health and fitness tracking excels on the Apple Watch

Both the Apple Watch and the Galaxy Watch have plenty of features to keep an eye on your vitals.

On the fitness front, the Apple Watch has 14 workout types built-in, while the Galaxy Watch has 39. Both also let you track any other type of workouts under the "other" category.

Each watch gives you an alert and vibration when they automatically detect some sort of workout happening, usually in the first 5-10 minutes of activity. But they're limited on the number of activities they can detect for you. They both do running, walking and some gym machines, but only the Apple Watch will autodetect swims, and only the Galaxy Watch can autodetect cycling.

The Apple Watch has an FDA-cleared ECG app on board. It also can alert you when it detects an abnormality such as high or low heart rate, or an irregular rhythm that could signal atrial fibrillation. Another feature alerts your loved ones and emergency services if it detects you've taken a bad fall.

The Galaxy Watch uses the heart rate sensor for fitness purposes and for tracking stress levels. And the Galaxy Watch automatically tracks your sleep if you wear it to bed, unlike the Apple Watch. It breaks down the duration and quality of sleep.

Here are the other fitness features on these watches:

Winner: Apple Watch

Apple Watch gets FDA-cleared EKG features

Music and podcasts

Both the Apple Watch and Galaxy Watch let you listen to tunes during a workout, with or without your phone using wireless headphones.

You can store songs from your library directly on the Apple Watch, or stream over LTE if you subscribe to Apple Music. The Apple Watch also lets you listen to podcasts in the native app. Spotify is also available, but at the time of writing, functionality is basic: You can use the Watch to control playback when your phone is within reach, but you can't store songs for offline listening.

The Galaxy Watch has more robust Spotify support if that's your streaming platform of choice, like downloading playlists to listen to offline if you're a premium subscriber.

The Galaxy Watch also lets you transfer songs you own from your computer, as long as they're on the same Wi-Fi network. You'll have to transfer podcasts this way and listen to them in the music app, rather than through a standalone podcast app.

Winner: Tie

The Galaxy Watch has stellar battery life

There's no contest here when it comes to battery life. We wore both watches simultaneously, getting the same notifications on each and using them both to track an indoor workout without LTE.

With this normal usage, the Apple Watch died after a day and a half, although it's possible to get almost two full days out of the smaller 40mm Apple Watch if you turn on battery saving features.

But the 42mm Galaxy Watch lasted at least another day, so it gave us almost three full days of battery before it needed a charge.

Samsung claims the 46mm Galaxy Watch can get up to four days of battery life, although we only tested the smaller version.

Having LTE active drains the battery faster, as you would expect. During an outdoor run, both watches drained at about the same rate, going from 100 to 90 percent after 35 minutes. We didn't listen to music during the workout, but if you stream over LTE, expect the battery to drain even faster.

Charging each watch is simple, as they both come with their own charging pads. The Apple Watch magnetically attaches itself to the charging pad, while the Galaxy Watch sits in a cradle that holds it sideways. The Galaxy Watch takes longer to reach a full charge than the Apple Watch.

Winner: Galaxy Watch

So which one is the best smartwatch?

Both are great smartwatches that help keep an eye on your fitness, get notifications and (gasp!) tell the time. If you want the watch with the greatest compatibility across platforms, plus extended battery life, the Galaxy Watch is the way to go. For iPhone users who want extensive fitness tracking and the added health features -- especially for heart-related issues -- go for the Apple Watch.

Apple Watch Series 4 review: Bigger, faster, even more health-conscious.

Samsung Galaxy Watch review: A worthy Apple Watch alternative.