Generally speaking, if getting information or advice on your overall fitness level is your primary goal, a fitness tracker offers comprehensive data while remaining relatively affordable. However, you should know that all fitness trackers are inaccurate and that you should take the stats you get from them as rough estimates, not exact statistics. This was true of all the trackers we tested. If you want accurate distance measurements, or if you're a runner, a GPS running watch provides that and has a better interface for tracking your pace and other stats while running, and it's better for capturing and comparing your data across outings. A smartwatch (for Apple or Android) is a good pick only if you're willing to pay extra for the smartphone connectivity it provides.
How we picked and tested
We tested seven wrist-worn trackers and one hip-worn tracker.
After narrowing 26 initial contenders down to seven trackers, we tested them as a group and individually. To gauge step-count accuracy, we wore all seven bands simultaneously for two full days. We tested how well each device captured distance by running one mile on a treadmill, and to measure heart-rate accuracy, we pitted each band against a Garmin chest-strap monitor for a sequence of 30-second intervals of jumping jacks and recovery and a five-minute steady-state treadmill run. Finally, we spent some quality time with each band, assessing the comfort, user friendliness of both product and app, sleep tracking, and overall impressions.
Feature-packed and equipped with an easy-to-read display and exceptional distance measuring, the vívosmart HR topped our test.
The Garmin vívosmart HR checks off nearly all of the boxes: It tracks steps, floors climbed, distance traveled, calories burned, and active minutes. Plus, it's waterproof. Its display is easy to read, and unlike other trackers' screens, you can customize it to show whatever metrics you desire. The display also shows smartphone notifications and the current weather along with music-player and camera remote controls, features its closest competitor, the Fitbit Charge HR, can't touch. Its distance-measuring accuracy is particularly impressive, even when compared with that of trackers sporting built-in GPS receivers. It also monitors heart rate continuously, keeping a record of both resting pulse and workout intensity; many rivals do one or the other but not both. Unfortunately, like every tracker we tested, the vívosmart's heart-rate data isn't always accurate. The only major downside is that Garmin's app isn't as good as its hardware. It's not as polished or user-friendly as Fitbit's or Jawbone's apps, but it has improved over time and will continue to get better.
Runner-up (with a better app)
The Charge HR has an excellent app and great social integration, but its screen is tiny, and its construction is only splash-resistant.
For about the same price, the Fitbit Charge HR offers a more user-friendly app and better opportunities for friendly, online competition than the Garmin vívosmart HR. Unlike our top pick, however, it's merely "splash-proof" rather than waterproof, and its screen lacks an always-on mode—you have to tap the display or move your wrist to view the time or other metrics, including your heart rate during a workout. This makes it inconvenient to read while exercising, which is one of the main reasons for having an HR monitor in the first place. On top of that, the Charge HR is only capable of receiving missed-call alerts, and its band is stiff and less comfortable than the Garmin's stretchy strap.
A stylish pick that gives you advice
The UP3 lacks a screen and active-heart-rate data, but it's attractive and discreet.
If you want not only to collect stats on your activity levels but also receive advice on what to do, look to the Jawbone UP3. It measures the same stats as our other picks (except active heart rate), and the slim band looks more like jewelry than a high-tech fitness device. Based on your data, the app's Smart Coach feature provides advice to make improvements to your health, which other trackers can't match. However, the merely splash-proof UP3 lacks a display screen, monitors only resting heart rate, and is more expensive than our other picks.
A clip-on pick for discreet tracking or team sports
For stealthy activity tracking, clip the Fitbit One on a pocket or waistband, or elsewhere on your clothing. For about half the price of our top wrist picks, you'll get the basics, including step and stair tracking, plus a record of your sleep if you wear the One at night with the included soft-fabric band. What you won't get is heart-rate tracking, or step counting that's any more accurate than what wrist-worn options offer.
This guide may have been updated by The Wirecutter. To see the current recommendation, please go here.