Inside the Charge 3 are an accelerometer, gyroscope, optical heart rate monitor, and an SpO2 sensor for tracking blood oxygen levels. The Charge 3 is the third Fitbit device to include an SpO2 sensor, following in the footsteps of both the Fitbit Ionic and the Versa smartwatches. However, currently the SpO2 monitor lies dormant inside all of these devices as Fitbit hasn't made use of it yet.
The Explorist and Venture cases are an average thickness for a round smartwatch (at 12.5 and 11.5 millimeters, respectively), with widths of 45 mm and 42 mm, respectively. Neither watch feels too heavy or awkward on a larger wrist, though even the smaller Venture watch is still quite chunky on a smaller wrist. Each model’s battery regularly lasted a whole day in our testing, and the voice-dictation functions are on a par with those of most smartwatches; the same goes for Google Assistant’s accuracy. Both watches and their Google Fit system track day-to-day activity, and although Wear OS apps don’t have quite the buy-in from app makers that the Apple Watch does, you can likely find your favorite apps in Google’s Play Store, and most phone apps provide rich notifications that you can interact with through the watch. Both show signs of good build quality, with thoughtful attention to detail on all surfaces and no cheap connectors or pieces.
My personal favorite watch for Android on the market today actually isn’t an Android Wear device, rather coming from Samsung and running atop Tizen. The Samsung Gear S3 Frontier is all the smartwatch you’ll ever need, with a sporty, circular gray design with a 1.3-inch Super AMOLED display that is the best I’ve personally ever used and is protected by Corning Gorilla Glass SR+.
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.