Basically, smartwatches are wearable-technology devices that maintain a relatively persistent wireless connection to your mobile device—usually a smart phone—and can receive notifications of incoming calls, texts, instant messages, social-network updates, and more, from that device. Some can also let you accept and conduct phone calls right on the watch. And even newer models (the Samsung Gear S, for one) can act as smart phones all on their own, without needing a paired phone nearby.
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.
Bottom line: Some fitness trackers work equally well with an iPhone or Android device, but some smartwatches are built to pair with Android phones so you won’t enjoy full functionality and pairing on an iPhone. The Apple Watch only pairs with the iPhone so is off limits to Android users. Your existing phone choice will play an important part in choosing a smartwatch. You can check your smartphone’s compatibility with a range of Google Wear-powered smartwatches at g.co/WearCheck
Samsung treads between smartwatch and fitness tracker, also packing in a heart rate sensor along with that GPS and its much-improved Samsung Health software. There's also the option of LTE (coming soon), if you wish for an untethered connection, with a standalone speaker for taking calls on the watch. It's now waterproof, too, adding swim tracking skills that are on par with the Watch Series 4.
Next is the big focus on health and fitness. The Apple Watch can monitor your heart rhythm and suggest you see a doctor if it detects something irregular, it can call the emergency services you've fallen over, and it will keep you healthy by tracking your run. These potentially life saving features are a major reason people are ditching their traditional watches for an Apple Watch.
The build is fantastic with IP68 waterproof and Corning Gorilla Glass DX+, and the display looks great with a resolution up to 360 x 360 and Circular Super AMOLED tech. On the larger model, the battery sports a capacity of 472 mAh, which powers the snappy Exynos 9110 Dual core processor. You can choose between Silver, Midnight Black, or Rose Gold color options, and the bands are interchangeable to match your style. But most importantly, with the Tizen-Based Wearable OS 4.0 that Samsung has optimized to work with their proprietary controls and apps, this will be the perfect sidekick to your Samsung phone.
Our top pick for most people is the Apple Watch Series 4 with GPS (starting at $399), which has a huge display, ultra-fast processor, Raise to Speak Siri, fall detection and a built-in electrical heart rate sensor for taking on-the-go electrocardiograms. It also runs watchOS 5, which makes the watch even more useful with automatic workout-tracking, offline podcast playback and a Walkie-Talkie voice chat feature.