4 star rating

Fitbit Flex Review

Pros: Minimal comfortable design; High level of customizability; Comprehensive suite of applications; Wide range of connected devices and services
Cons: Android app a bit buggy
The Verdict: With a svelte design, low price and a well-developed app ecosystem, the Fitbit Flex is the best all-around fitness-tracking band available.



When it comes to personal fitness devices, Fitbit has a strong track record of connected scales and health trackers. However, the company recently fell behind the curve in the realm of wearable wrist devices such as the Nike+ Fuelband and Jawbone UP. No more. The Fitbit Flex is a wristband that tracks your daily activity as well as sleep patterns. At $99, it's less expensive than other offerings, too. Find out why the Flex is the must-have wearable fitness device of 2013.

Article Continued Below


Fitbit FlexThe Fitbit Flex is the definition of minimalism. It's a small, flexible, rubberized band with notches on one end and clasps on the other to secure the device to the wearer's wrist. Weighing 0.47 - 0.51 ounces (depending on the band you use) and less than 0.5 inches at its thickest, the Flex is the most comfortable fitness band we've tested; even when we spent hours on end tapping away at a keyboard, the Flex was so comfortable we often forgot we were wearing it at all.

Getting the band on your wrist is a slightly different story, as we had to push down so hard on the clasps to secure the device that it would sometimes leave a temporary indentation on our skin.

Fitbit FlexOf the wearable fitness-tracking devices, Fitbit's Flex is the most customizable. Instead of the band and tracker being one unit, as with Nike's Fuelband and the Jawbone UP, the Flex's activity tracker is a small, pill-like device that's housed in the separate, rubberized band. The retail package comes with two colored bands, one small and one large, in either black or slate. The company has confirmed that slate, black, teal, navy blue and tangerine will be available at launch for $15 each, while a combination pack of teal, navy and tangerine bands will be available for $30.

MORE: Top Fitness Gadgets for 2013

The Flex is water resistant, and users can wear it safely in the shower or even while swimming at depths up to 10 meters (about 33 feet). The band also comes with a USB charging cable and a USB dongle, the latter of which can be plugged into your computer to wirelessly sync when your Flex is in range. A series of five blinking lights on the Flex will show progress towards your step goal as the day goes by, with each bulb representing 20 percent achievement.


Fitbit FlexFitbit has free companion applications for Android and iOS. The app shows your daily progress compared to established goals for number of steps, miles traveled, calories burned, sleep schedule, water consumption and caloric intake. A drop-down menu on the Android application provides further detail on your movements and sleep patterns in the form of charts and graphs, and the same is achieved via a bottom menu on the iPhone.

Of course, Fitbit knows that there's more to health tracking than just keeping tabs on your steps and sleep patterns. Both the mobile applications and Fitbit's Web-based management system allow you to manage and track your weight, body fat percentage, food and water consumption, and additional exercise activities performed throughout the day.

While the iPhone app worked as advertised throughout testing, we ran into a few issues with the Android version, most noticeably with graphs and charts failing to properly load. Fitbit is aware of these issues and will hopefully have fixes before launch. The company updated the Android application three times in the week we had the device.

MORE: 10 Best Fitness and Workout Apps

Syncing Your Device

Fitbit FlexData from the Flex can be synced to your smartphone or to Fitbit's Web dashboard (which can be accessed via https://www.fitbit.com/login). You can sync the Fitbit Flex via a wireless USB dongle or Bluetooth 4.0. When in range, the Flex will wirelessly sync with the included USB dongle as long as the device is plugged in and your computer is on.

The Jawbone UP, by comparison, forces you to plug the device into your smartphone's headphone jack in order to sync data.

If your phone has Bluetooth 4.0 connectivity and is on Fitbit's approved list of devices, the Flex will automatically update whenever your handset is in range. The iPhone and iPad, along with Samsung's Galaxy S III and Note II were all supported at the time of publication, though more devices will likely be added soon.

Diet Assistance

Diet is a key driver of overall health, and Fitbit Flex allows users to track their daily food consumption. The device has a comprehensive database of foods, and this database aims to make the tracking process as painless as possible. Searching for "banana" on the Fitbit Web application returns over 600 results, though the options are a bit more limited on the mobile applications, which returned around 30 results.

Once you've logged your meals, Fitbit will store this information in your most recent and most frequently used sections in the Add Food menu. You can also add foods you eat regularly to your Favorites, which then get stored in My Foods for easy adding later on.

Sleep Tracker

Fitbit FlexRapidly tapping on the Fitbit Flex for a few seconds launches sleep mode; under this setting, the device will track your sleep patterns throughout the night. When you awake, Flex presents you with information on how deep your sleep was, how long you slept and how many times you woke up. Flex also comes equipped with a Silent Alarm, which vibrates your wrist to wake you up at a predetermined time.

As someone who has trouble sleeping when the conditions aren't perfect, this tester was a bit worried about trying to fall asleep while essentially wearing a bracelet. Fortunately, the Flex is very comfortable on the wrist, and didn't affect sleeping patterns.

MORE: 5 Reasons You'll Wear a Smart Watch

Apps and Accessories

Fitbit FlexFitbit has an extensive API available to let third-party developers integrate their data into Fitbit's dashboard. As of this writing, there are 27 popular fitness applications available to use with the Fitbit, including Lose It!, Map My Run, My Fitness Pal and Endomondo. These apps will help you better incorporate your fitness and dietary data into Fitbit's system. Jawbone and Nike also have APIs available to developers, though Fitbit has the most comprehensive offering to date.

Jawbone currently syncs with 10 apps: RunKeeper, My Fitness Pal, Map My Fitness, Withings, iFTTT, Wello, Notch.me, Sleepio, Lose It and Maxwell Health.

Fitbit also produces a WiFi scale, the Aria, which automatically uploads your weight and body fat data whenever you step on the scale. The Aria will set you back about $130.


What good is getting in shape if you can't brag about it? Fitbit lets you connect with Facebook friends or email contacts to share your fitness data. Connecting will let you encourage friends to keep at their goals, while Fitbit's leaderboard creates some competition. You can also share your daily results via Twitter, Facebook, Wordpress.com and Microsoft Health Vault for those friends without Fitbit accounts.

Battery Life

Fitbit FlexFitbit says the Flex will get between 5 and 7 days on a single charge. In our testing, that claim was fairly accurate; we only had to charge the device on day 6, putting the battery life on a par with other offerings, but below the 10 days we saw with the Jawbone UP. When the Flex syncs with your smartphone or tablet, the About Device section provides an overview of the remaining battery life on your Flex. However, it does so via a graphical overview instead of a solid percentage or time remaining like on competing devices.


Fitbit FlexThe Fitbit Flex brings all the types of tracking tools needed to manage your path to better health, and, at $99, costs $30 less than the Jawbone UP and $50 less than the Nike+ FuelBand. The Flex is also the most comfortable gadget in this category to wear, works with more apps and can sync wirelessly with a greater number of devices. Fitbit has flexed its muscles in the wearable device market, and with its svelte design and low price point, the Flex is the new device to beat for people looking to take charge of their health.

Tags: fitbit flex, reviews, Fitbit, wearable tech, Fitness

Technical Specifications
Fitbit Flex

Accessories TypeApple Accessories; Bluetooth Device; Cell Phones Accessories; Recording Device; Toys
Battery Type/Life
Weight0.47 - 0.51 ounces (depending on band)
All Product Types Accessories eReaders Laptops Networking Projectors Smartphones Software Storage Tablets
All Subcategories
All Subcategories All-Purpose Budget Business Desktop Replacement Gaming Multimedia Netbook Nettop Rugged Student Tablet PCs Ultraportable
Acer Alienware Apple Archos ASUS AVADirect Averatec BeagleBone BenQ CTL Corp. CyberPowerPC Dell Digital Storm eMachines Emtec Eurocom Everex Fujitsu GammaTech Gateway General Dynamics Getac Gigabyte Google Hercules HP HTC iBuyPower Intel Lenovo Maingear MSI Nokia Nvidia OCZ OLPC OQO Origin Panasonic Razer Sager Samsung Sony Sony PlayStation Sylvania Systemax TabletKiosk Toshiba Verizon Viewsonic Viliv Vizio VooDoo Workhorse PC ZT Systems
Minimum Rating
Any Rating Editor's Choice 4.5 Stars 4.0 Stars 3.5 Stars 3.0 Stars
Screen Size
10 11 12 13 14 15 16 17 18 20 21 4 5 6 7 8 9
1024x576 1024x600 1024x768 1136 x 768 1200X800 1280 x 720 1280x1024 1280x768 1280x800 1366x678 1366x768 1440x1050 1440x900 1600x768 1600x900 1680x1050 1680x945 1792 x 768 1900x1080 1920x1080 1920x1200 2560 x 1440 2560 x 1600 2560 x 1700 2880 x 1620 2880 x 1880 3200 x 1800 3840 x 2160 800x400 800x480
Weight Range
10.1 - 12.0 pounds 12.1 - 14.0 pounds 14.1 - 16.0 pounds 2 lbs 2 pounds and under 2+ lbs 2.1 - 4.0 pounds 4.1 - 6.0 pounds 6.1 - 8.0 pounds 8.1 - 10.0 pounds Over 16 pounds Under 2 pounds
more options