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.
When it comes to smartwatches, one size most definitely does not fit all. The best option for you depends on a number of factors, including the smartphone you use; whether you want strong activity-tracking features; your budget; and your aesthetic tastes. For example, many people prefer a smartwatch with a round display because it looks more like a standard wristwatch than a piece of tech. You'll want to take all these factors into consideration when you begin the search for the best smartwatch for you. So whether you’re looking for something appropriate for dinner parties or back-country trails, high-end, budget or something in between, we’ve tracked down the best smartwatches on the market this year.
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.
We test every new smartwatch to gauge its design and comfort. If it’s not stylish and comfortable enough to get you from an early morning workout to the office to a night out, you probably won’t wear it every day. Most smartwatches are also fitness trackers, so we put all of its sensors to the test, from step counts to heart rate to GPS (when applicable).