Lately, I have heard various friends say “I have to get my 10,000 steps in.” It has become sort of a game for many to achieve this daily goal in an attempt to stay active, lose or maintain weight, and stay healthy. The fitness wearable-device market has evolved over the last few years. Just a few years ago, wearable fitness devices like the BodyBug would cost upwards of $300. The latest batch of wearables includes the Fitbit Flex and Jawbone Up, which cost $129 and $99 respectively.  But, which one is better? The answer is, it depends on your particular situation.

The Fitbit Flex and the Jawbone UP both have 3 axis accelerometers that measure steps, sleep, calories and food. They both are water resistant. You can shower with either unit, but swimming or other water activities are not recommended. They both have mobile apps for iPhone and Android. However, they have various distinguishing features and, depending on what type of user you are, these differences can make you fall in love with your activity band or think it’s too much of a hassle.  

Style and Comfort

The Fitbit Flex and the Jawbone Up are both fairly comfortable to wear. Similar to a wrist watch, after a little while you forget you are wearing it. However, both have design weaknesses.  The Jawbone Up coil design makes it easy to take on and off your wrist, but it does tend to snag or get caught on long sleeves. At night, it can get caught on pillows and sheets. In comparison, the Fitbit Flex can be a little tough to get on, but doesn’t get caught on anything.  Both the Fitbit flex and the Jawbone Up come in fashionable colors.  However, only the Jawbone Up allows you to change the color of the band (each color sold separately) to match your mood or what you are wearing.   

Sleep Tracking

Unfortunately, neither device automatically detects or switches directly to sleep tracking mode without user intervention. However, the Jawbone Up’s one touch button lets you go into sleep tracking mode much easier than the Fitbit Flex. In order to get the Fitbit Flex to go into Sleep mode, you must continually tap the device for a few seconds. This process takes a little getting used to and isn’t that user friendly.  The Fitbit Flex allows you to edit your sleep time, but it isn’t as accurate. The Jawbone Up also goes into its awake activity mode automatically, whereas the Fitbit Flex needs user prompting. 


Both devices have free iPhone and Android Apps available, and both have the ability to connect with friends that use either a Fitbit device or the Jawbone Up. However, only the Fitbit Flex has a web interface that you can access on any computer connected to the Internet.  The Jawbone Up does have superior iPhone and Android based apps, with better graphics and interactive charts. Plus, it is a bit more user friendly than the Fitbit Flex. You can purchase a one year premium service from Fitbit that gives you in-depth analysis of your data and other features for additional $49.99 per year.  


The Fitbit Flex is the clear front runner with the use of low power Bluetooth wireless real-time syncing. In order to use this feature, users must have an iPhone 4s or later, or a Samsung Galaxy 3S or later. A complete list of compatible phones can be found on the Fitbit website. If the user has another phone, the Fitbit Flex will sync wirelessly through the use of a wireless USB dongle and an Internet connected computer. The Jawbone Up must be connected to the phone using the phone’s 3.5 mm audio jack in order to sync. The 3.5 mm end of the Jawbone Up is protected by a cover but this cover can come loose and eventually could be lost.  

Charging and Battery life

Both devices have internal rechargeable batteries. Each one must be recharged using their proprietary USB chargers. Both recommend that the user charge the device when they are not going to be active, such as when the user is sitting at work or watching a movie. A full charge can be accomplished in a couple of hours. The average battery life for the Jawbone Up was just short of 10 days and the Fitbit Flex lasting just shy of 5 days before needing to be recharged. 


Neither the Jawbone Up nor the Fitbit Flex is very accurate when it comes to distance or true amount of steps. Throughout my testing, I saw between an 8 to 15 percent differences in accuracy. In my testing, I used a hip based pedometer and in some cases, a Garmin 910XT with a foot pod over the course of several days to see how accurate each device was. The tests included walking up flights of stairs, walking vs. running around a quarter mile track, jogging in place, running on a treadmill and walking around a grocery store with a shopping cart. There were mass fluctuations in both steps and distance between the two devices, and when compared to the pedometer or the Garmin.  Sometimes the devices were overly generous on steps, and in other cases they did not record steps. During the shopping cart test, my hands remained on a shopping cart throughout most of the grocery store. I made sure to sync each device just prior to walking into the store and again while exiting. In this particular test, each device registered less than one hundred steps while the pedometer registered over one thousand. This is due to the fact that there was not enough movement in my arms, therefore the devices did not register the step.  Both devices will allow you to calibrate your steps to hone in on your distance but again depending on how you use the device it may or may not count your steps.

Bottom Line

Both activity monitors provide an excellent snap shot of your daily activity level, the quality of your sleep and eating habits. However, no activity monitor will work for you unless you actually get up off the couch and move! Neither is made to replace an activity specific device like a Garmin or sports watch. Both have sharing capabilities that allow you to support, compete and motivate your friends. So perhaps the best question to ask is which device do your friends currently own?