The Charge 4 is our hands-down favorite fitness tracker for its mix of good looks, easy-to-navigate device menus and companion app, long battery life, and plethora of activity- and sleep-tracking info.
The setup is a cinch for getting the device and app up and running. Once in use, the Charge 4 makes itself known, with hourly reminders to move and a 250-step countdown to hit before you sit back down. The Charge 4, like the other Fitbits and Garmins we tested, also automatically detects sustained activity, based on the movement patterns and heart-rate data the watch records, giving you credit for it in the app. Walks, runs, and bike rides especially are chronicled pretty accurately within a minute, plus or minus. (Though it’s not foolproof: a vigorous laundry folding session could give you credit for “sport.”)
If you prefer not to rely on the device to automatically recognize your workouts, you can turn on an exercise mode, selecting from seven on the watch that you pre-set from about 15 options on the app. The Charge 4 has built-in GPS, as opposed to its predecessor’s “connected GPS,” which requires you to bring your connected smartphone along if you want mapping and more accurate paces for your walks, runs, and bike rides. The Charge 4’s GPS worked well on my test runs and bike rides, recording distance measurements on par with the Garmin Forerunner 245 running watch against which I tested it. However, the Charge 4 has a small screen that’s hard to read in the sunlight and takes a split-second to wake up (and turns off almost as quickly), making it difficult, if not frustrating, to scope your stats mid-workout. For that reason, I recommend that dedicated runners who want to eyeball their pace, distance, or duration as they run consider a dedicated running watch instead.
Fitbit offers an extensive and active community centered around step-focused challenges, something that no other fitness-tracker company has had the same success replicating. Having a social aspect to help you set and meet goals can be a driving factor for sticking to your wellness plans, and the community is a selling point for Fitbit fans. During our first round of testing, Google announced it was acquiring Fitbit, which raised privacy concerns regarding how the tech giant might use all health data accumulated from its vast network. The EU approved the merger in late 2020 with a few concessions from Google—most importantly that it won’t use Fitbit data to target users for ads. The US has not yet approved the acquisition.
The Charge 4’s sleep tracking seems to record accurately, and as a troubled sleeper, I noticed it captured my middle-of-night restlessness better than some other devices. I also liked perusing the deeper data on resting heart rate (which I suspect is accurate), and time spent in deep and REM sleep (though without a sleep lab analysis, I can’t speak to that accuracy). It also records a Pulse Ox measurement during sleep, which could flag a dip in blood-oxygen level to bring to your doctor’s attention if you suspect you may suffer from sleep apnea.
Which brings up another point about accuracy—namely, that of the Charge 4’s optical heart rate monitor. As a rule, wrist-taken heart rate will never be as accurate to the second as data measured by a chest heart-rate strap by virtue of its distance from the heart. It is fine for tracking trends (such as keeping a record of average resting heart rate), but I’ve never had much success using it for measuring changes in exertion while training, and especially Fitbit’s technology in particular. With the Charge 4, Fitbit unveiled heart rate zone training alerts, which can only be as useful as the data is accurate. Unfortunately, in my experience, it’s just not.
The Charge 4 offers some additional user-friendly health features, including a breathing activity for stress reduction, menstrual cycle tracking, a hydration log, and a food log with a searchable database of common foods. You can also access pay-to-play workout, meditation, and other wellness programs through the Premium app upgrade, at a cost of $9.99 per month.
Among the Charge 4’s smartphone features are notifications, which you can customize or turn off entirely if all that buzzing gets on your nerves. You may reply to texts from the watch using preset canned replies and emojis, but if you want voice-to-text to reply in your own words, you should consider a smartwatch. You can also use Fitbit Pay, which allows you to upload credit card information and make payments when you're on the go.
Unless you strongly desire a larger screen for its looks or readability, we think most people will prefer the smaller overall size of the Charge 4, particularly for sleeping, despite the compromise to the display. (But if you want fitness tracking in a larger-screened smartwatch, read on.)