Best wristband fitness tracker

  • Very accurate
  • Comfortable
  • Optional bands and pendants available
  • Effortless data uploads
  • Basic LED display
  • Doesn't track stairs climbed
Where to Buy

Bottom line

The Fitbit Flex offers wireless syncing and compatibility with a wide range of devices as well as a number of fitness sites. It has a basic LED display that users say takes a bit of practice to interpret, but that they enjoy its perky celebrations when they reach their goals. It does not track steps, but owners say it's attractive and very accurate, and they like that its appearance can be tailored with a variety of available bands and bangles.

Breaking it down


Effortless connection to most platforms. The Fitbit Flex includes a wireless dongle and Bluetooth connectivity, letting you sync the tracker with most iOS, Android, OS X and Windows mobile devices, as well as with Apple and PC laptops and desktops. It tracks steps, overall distance, number of minutes spent doing cardio-type activities and calories burned. Because it does not include an altimeter, it can't track steps climbed, which many say makes it more suitable for casual users than for serious athletes. However, experts and users say it's one of the most accurate fitness trackers on the market, with an excellent fix on the subtlety of various levels of activity. It can also track sleep; either in "sensitive" mode for detailed sleep reporting or "normal" mode for a more general gist of sleep patterns. The Flex includes a vibrating alarm to wake you, but not your partner.

Ease of use

Fitness at a glance. There may be a bit of a learning curve with the Fitbit Flex's LED display. It uses five white lights to signify progress toward your daily activity goal; but you need to learn what stage each flash means. To get specific stats, you'll need to sync your Fitbit with a smartphone or computer to see the data, but owners say that's smooth and effortless. A couple of taps puts the activity tracker into sleep mode. Experts say the fitness support -- both through Fitbit's web account and mobile app -- is some of the best available, with detailed information to track your progress by the minute or over the long-term. Data can also be uploaded to a variety of other fitness sites and apps.


Slender, discreet bracelet. The Fitbit Flex is smaller, less expensive and lasts longer between charges in comparison to other, bulkier bands, say reviewers. The tracker itself is removable from the band, so users can change the look of the Flex. There are wristbands available in a variety of colors, with more coming on the market all the time. For the serious fashionista, there is a line of Tory Burch bracelets that are pricey, but gorgeous, reviewers say. Quite a few warn that the clasp on the standard wristbands can unclip without warning, and plenty of unhappy owners have looked at their wrist to check their progress only to find that their Flex had fallen off at some point and was lost.

Where To Buy
Fitbit Flex Wireless Activity + Sleep Wristband, Black

14 New from $79.95

In Stock.


Fitbit Flex Reviews


The Fitbit Flex earns a 4-star rating at Jill Duffy says the Flex is comfortable with excellent battery life. She notes that it's one of the best wrist-style activity trackers, but has a limited display on the device and does not track steps climbed.

Review: Fitbit Flex, Jill Duffy, May 6, 2013


Editors at test a handful of activity trackers, including the Fitbit Flex. Accuracy is tested using activity on a treadmill, elliptical machine and stairs and picking toys up off the floor. Testers also rate how well the device estimates calories burned, how easy it is to use and overall features.

Review: Fitbit Flex, Editors of, Not Dated


Brian Bennett gives the Fitbit Flex a thorough reviews, ultimately awarding it a 3.5-star score and rating of Very Good from. He says the Flex offers simple tracking and syncing, but the real power lies in Fitbit's fitness platform.

Review: A Most Versatile, Feature-Packed Tracker, Brian Bennett, June 20, 2013


The Fitbit Flex is more accurate at measuring activity than the clip-on Fitbit One, says Danny Sullivan. He finds this especially important for non-step activities like paddle-boarding. Because of its comfortable design, helpful motivations and powerful fitness app, Sullivan prefers the Flex over the other trackers he evaluates.

Review: My Life with the Fitbit Flex Activity Tracker, Danny Sullivan, May 12, 2013


Lee Crane gives the Fitbit Flex a score of 3 out of 5 stars, saying its appearance is sleek and the automatic data syncing is much appreciated. However he notes that, because of its difficulty in tracking non-step activities and some cumbersome procedures, the Flex isn't well suited for serious athletes.

Review: Fitbit Flex Review, Lee Crane, June 15, 2013


Andrea Smith names the Fitbit Flex as the best activity tracker, giving it a perfect 5-star rating. She finds it has the best design and a long-lasting battery, is easy to sync and integrates with other fitness apps.

Review: The Best Activity Tracker: Fitbit Flex, Andrea Smith, Oct. 14, 2013


The Fitbit Flex is a #1 Best Seller in Health & Personal care, with well over 9,000 customer reviews, yet it earns an average rating of only 3.7 stars out of 5. In addition to complaints about durability, some say the wrist strap unclips too easily, resulting in lost trackers. Many love it, however, saying it motivates them to move more.

Review: Fitbit Flex Wireless Activity + Sleep Wristband, Contributors to, As of December 2014


After more than 4,600 customer reviews, the Fitbit Flex earns an average rating of 4.3 stars out of 5. About 90 percent say they would recommend the Flex to a friend. The fitness tracker gets plenty of praise for being easy to use, attractive, comfortable and useful.

Review: Fitbit-Flex Wireless Activity and Sleep Tracker Wristband - Black, Contributors to, As of December 2014

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