While internal hardware varies, most have an electronic visual display, either backlit LCD or OLED or Hologram. Some use transflective or electronic paper, to consume less power. Most have a rechargeable battery. Peripheral devices may include digital cameras, thermometers, accelerometers, pedometers, heart rate monitors, altimeters, barometers, compasses, GPS receivers, tiny speakers, and SD cards, which are recognized as storage devices by many other kinds of computers.
Apple has continued its focus on its health focus with the Series 4. In addition to being able to detect a fall, this new Apple Watch introduces three heart-rate tracking features that will be available later this year. It lets you know if your heart rate is too low, it can detect irregular rhythms (which may indicate atrial fibrillation), and most impressively, it serves as an FDA-cleared electrocardiogram.
Being able to customize the watch faces and layouts, made the Series 3 a shoo-in for our list of best smart watches. Much like you can customize the homescreen on your iPhone, you can change the layout of apps and even display the weather. While you can’t opt for third-party designs, you do have 12 different watch faces to play with. Tinker with color schemes, add or remove widgets (called “complications” on the app), and decide whether you want to have all twelve faces available on your watch (we always like having options), or cut back.
The Galaxy Watch comes in two sizes, 46mm and 42mm, both with an OLED display and an “optimized” chipset that extends battery life. For the larger model, you can squeeze 6 days out of a single charge while the smaller model still offers up to 4 days. As you’d expect, the Watch also includes features like GPS, water resistance, and there’s NFC for Samsung Pay.
The screen is great, and the pre-installed watch faces make it stand out from rivals. Android Wear feels very samey across all devices, but it's a well developed OS. It's reasonably intuitive and simple, but there's a little too much swiping and tapping on the small screen. It also works across both Android and iOS, although iPhone functionality is limited (no apps etc.)
The Fitbit Ionic works fine as a Fitbit tracker, but despite being more expensive than our picks or the Apple Watch Series 1, it lacks many smartwatch functions you’d hope to have. It passes notifications from your phone to the watch, but you can only respond to some of them (with only five quick reply lines); and dismissing them (either one by one or as a group) involves annoyingly hard presses and long scrolls. Syncing music files and offline Pandora playlists requires you to use a desktop app, which is laborious. Two Wirecutter writers who tested the Ionic also had trouble setting it up to work with their Android phones (a 2015 Moto X Pure and a 2016 Samsung Galaxy S7) and had to perform significant troubleshooting to get their data to sync. The Ionic’s battery life, even while using GPS for outdoor exercise tracking, is its most impressive feature, lasting at least five days in one test and nearly seven days in another. The Ionic is most useful to Fitbit enthusiasts who want to track outdoor exercise without bringing a phone; it’s not a good option if you’re looking to deal with incoming information.
The Apple Watch Series 4 is now on sale, and it's the best smartwatch you can buy right now. The redesigned device, which starts at $399 for the GPS model and $499 for the cellular version, is the best smartwatch you can buy. It has a larger display and slightly bigger case size while retaining the same rounded square design the watch is known for. Even more importantly, Apple received FDA clearance for a new electrocardiogram feature that can take a 30-second EKG and diagnose atrial fibrillation.