Fitbit Wireless Activity & Sleep Wristband

Priced: $99.95 Rated:   - 3 stars out of 5 by 49 reviews.
Fitbit Wireless Activity & Sleep Wristband
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Fitbit Wireless Activity & Sleep Wristband -

A perfect companion day and night, the Fitbit Flex Wireless Activity & Sleep wristband helps you achieve your fitness goals by tracking movements, activities, your quality of sleep and more.



  • Slim and stylish wristband doesn't scream fitness tracker, but subtly says, "check out my cool rubber bracelet"; includes a small and large wristband for the perfect fit
  • Make fitness social by connecting with friends through the app to share results, compete with each other, or simply share some encouragement

Weather and Wind:

  • Water-, sweat-, and rain-resistant design. Not intended for prolonged submersion


  • Silent wake alarm gently vibrates to wake you—no more terrifying alarm clock noises!
  • The Flex tracks your steps taken, calories burned, hours slept, distance traveled, minutes active and your quality of sleep
  • Download the iPhone or Android app and sync your real-time stats via Bluetooth® to track your progress throughout the day
  • Compatible with iPhone 4S and newer, iPad 3rd generation and newer, iPod touch 5th generation, Samsung Galaxy S III, Samsung Note II, PCs and Macs
  • 5 built-in LED indicator lights let you monitor your progress; each light represents meeting 20% of your goal
  • The Flex Wireless Activity & Sleep Wristband includes the tracker, small and large wristbands, charging cable and a wireless sync dongle USB device
  • Rechargable lithium-polymer battery lasts 5 - 7 days per charge
  • App also lets you set goals, log food and workouts and monitor your sleep trends
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Review RatingNumber of Reviews
Analog or Digital:Digital
Dimensions:Fits wrist circumference: (Small) 5.5 - 6.9/(large) 6.3 - 8.2 inches
Exercise log:Yes
Heart rate display:No
OS compatibility:Windows / Mac
Pedometer type:Digital 3-axis accelerometer
Tracks calories burned:Yes
Tracks distance:Yes
Tracks steps:Yes
User replaceable battery:Yes
Weight:0.45 ounce
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Fitbit Wireless Activity & Sleep Wristband Reviews:

Positive Reviews:

enjoying the Fitbit so far

I would say the design of the device is simultaneously a pro and a con. Clearly they were aiming for a more minimalist look, so there are no controls on the band, and very minimalistic display. I like this because the device looks OK to wear to work or social events. I don't suppose I'd wear it if I were going to some highly formal occasion.

The minimalism means that you only get an approximate view of steps taken so far during the day, on the display. You turn on sleep logging by tapping the device - sometimes this works right away, but sometimes you're furiously tapping and all it will do is keep showing you the steps taken display.

There is always the option to manually log your sleep start and stop times on your phone or computer the following morning, if you can't get it to work on the bracelet.

The other caveat is that it isn't a super sophisticated sleep monitor (like the high end ones where you actually wear a sensor on your forehead). If you wake up, and then are completely still for a while (and yet awake), and then roll over and fall asleep, the readout will interpret that as two brief awakes with an interval of sleeping in between. So "sleep time" on the final readout has a good chance of being overstated.

That said, I'm finding it helpful to track the trends with my sleep and I AM finding that tracking my steps every day is incenting me to take more steps. I've tried using pedometers before but found it was a hassle to remember to put it on every morning and to move it when I changed clothes. With the bracelet system, it's on all the time with absolutely no effort on my part.
cloud9mn at REI on 09/09/2013

Accurate enough for me

If you are an avid exerciser who wants every possible metric about your performance, the FitBit Flex probably isn't for you. It really is primarily a pedometer that will count your steps, though you can go online and enter different activities (like cycling, swimming, etc.) if you know the start time and duration and FitBit will calculate the "steps" equivalent. For cycling, I've had the best luck getting Endomondo to sync correctly and do the calculations right, though MapMyRide is supposed to work as well.

One of the things I like most about it is that it's very difficult for me to lose it -- I wear it on my wrist 24/7 and only take it off to charge it. Every other pedometer or activity monitor I've had was one that clipped to my clothing and I would constantly lose it or forget to put it on. I don't have to worry about that with the Flex, because it's always on my wrist and I don't even have to think about it.

It is VERY important to figure out your stride length and enter that into your Dashboard online (you can have separate stride lengths for walking and running). Once I did that and synced up, the information I got was far more accurate. People who are having trouble with accuracy should be sure to take this step -- I think they will be much more pleased with it once they do.
cinegirl_la at REI on 09/09/2013

Great Product!

I love this product. It syncs with and you personalize your profile to measure a compendium of personal stats. The sleep tracking was interesting as it showed what time I went to bed, how long it took me to fall asleep,when I got up, if I was restless, total hours of sleep and total hours in bed. Amazing! My sleep was much different than I thought. I think it's accurate based on the steps/calories measured by my other pedometer, but even if it isn't it is accurate for me day to day and that's fine for my use. I am wearing it on my dominant hand which is not recommended, but I wear a watch and they didn't both fit on my wrist. I am obsessed with the tracking part on the website and my awareness of exercise and what I eat has increased tenfold. One cool feature is that when you reach your activity goal for the day, 10,000 steps, 10 miles, whatever you input, it vibrates and buzzes very softly and the lights go crazy in celebration! It's a little private moment of self satisfaction. Great positive reinforcement. If I was an avid athlete, I think I would be even more into the possibilities of the device. The only con is that you have to take it off to charge it and you lose that tracking time. Otherwise I haven't removed it since I bought it.
Holly at REI on 06/06/2013

All that I wanted it to be...

I purchased the FitBit Flex to replace the FitBit Zip my company gave all employees. I wore the Zip every day and met the company goal of a 1,000,000 steps. I decided this technology was going to be a constant part of my life/routine and wanted to upgrade and move away from the shifting the Zip between clothing changes. It works just as well as the Zip and the sync is faster and more consistent. I do miss the digital screen of the Zip to know where your goal is for the day, but I always carry my phone and just get in the habit of checking my progress for the Flex.

The Flex is very consistent with my RunKeeper program for distance. I have enjoyed getting feedback on my sleep patterns. I wear it 24/7 and have had no issues with showering. I will purchase one for my wife when she meets her 1,000,000 program.

I really enjoy the feedback and challenge of meeting my goal. It has really helped my wife and I understand how hard it can be to stay active when juggling work and kid schedules. It really helps see what it takes to burn off the calories you take in for the day and gets you motivated to get your steps.
Highland Crew at REI on 06/06/2013

Worth Every Penny.

Fantastic product! I researched activity bands for months before buying the Fitbit Flex and I am convinced it is the best! It was easy to learn to use, gives me the info. I need about my sleep and activity, and is highly motivating.

I love the silent alarm feature. I am also greatly enjoying being "walking buddies" with my friend who lives several States away. Now that we are Fitbit Friends it is easy to cheer each other on and keep up with our goals. Your Friend's info. pops up on your Dashboard (alongside yours) and you can reveal as little or as much as you want with others about your personal progress and stats.

I have noticed that the window on my bracelet is already scratched, but I am not worrying with trying to protect it or keep it perfect. I have worn it day and night, and in the shower, and expect to go through several wristbands (in all colors!) over time. They are inexpensive to buy. The internal piece slides in and out easily but is secure once inside.

The Flex does everything I hoped it would and has surprised me by doing even more as far as syncing easily with computer and linking to FBook.
Amber at REI on 06/06/2013

Good device

I used to work out avidly, and received this device as a gift for Christmas and I'm looking forward to using it more extensively as I get back into my workout routine. For the time being, I have been using this only in a sedentary lifestyle. So far, I've been happy:

The band and clasp work fine, I have had no issues with it and actually think it's a good design.

The silent vibrating alarm is a nice feature, but it doesn't start soft and build up - it just goes straight into vibrating which can be startling when it's unexpected.

It's mostly accurate. The sleep log of my first two nights were accurate, the third was not and the fourth night it didn't even capture my pattern.

Activities seem to be accurate.

I wish there was a larger database for foods, such as with MyPlate. A lot of times I just have to guess at what I'm eating and enter the info manually.

I like the device quite a bit, and I'm thinking of upgrading to the Force model so I can have a better display and time.
michaelholdren at REI on 01/01/2014

Overall a decent pedometer

I have worn this for a month solid. It is relatively durable and unobtrusive. The tiny 'display' is functional, but they should have built some sort of watch/time function in. The band is comfortable, but somewhat difficult to fasten the first few times. The tiny fitbit unit itself fits within the band. You have to remove it from the band to charge the device. You must either synch the device to your phone (limited compatibility.. see the fitbit site) or use the included USB wireless adapter. It works really well with my Samsung Galaxy S4. It also integrates with several food/caloric tracker applications. The sleep function isn't perfect, but it does provide some interesting reference data and has helped me determine foods/patterns that make me restless at night. I would have given this 5 stars except for the charging cable. The connectors on the fitbit are proprietary and you have to use the included cable to plug into a USB port or standard charger. I lost a cable and the replacement was $20 plus shipping. VERY annoying. Having to remove from the band to charge is also kind of annoying.
ClintS at REI on 09/09/2013

Good for the money

I bought this to keep my motivated to workout. I liked how there was an app for Android and iOS. What I noticed, was when I woke up in the morning, it already gave me 400 calories burned. That seemed a bit odd. There are many questionable measurements for counting the calories imo.

I also wondered how it would keep track of me doing P90x videos. I compared a Cardio Video of P90x to walking for 30 minutes outside and it gave me roughly the same amount of calories burned. I knew it wasn't going to be that accurate so I'm not complaining about it. I like all the added features and the website is great to use to see how you're doing with calorie intake vs burned and total steps. The sleep analysis is my favorite cuz it's making me get to bed earlier so I have that on record.

Overall a great product for the money.
filupmybowl at REI on 08/08/2013

perfect for work

This is great for me because it forces me to get out of the house on my off days and go for walks. I work as a tour guide so it's been neat to see how far we walk during a single tour.

The awkward thing is the dashboard and the way it syncs to some other fitness sites. It's probably just because I'm still getting used to the new website.

I'm enjoying the fit bit. It's comfortable and I don't constantly have to charge it, which is amazing.It's unobtrusive. People don't know it's a pedometer or tracker, they think it's my watch. It's subtle, and I don't concentrate on numbers during the day. I think it's a wonderful tool.
rebelrugger at REI on 06/06/2013

Great Hardware, Mediocre App

I wear the Flex day in day out. I do lots of walking, every other day at the gym (boxing, calisthenics, stationary bike).

The device itself is great. It's lightweight, compact, and relatively discreet. The best part is that you often forget you're wearing it.
*Battery life is pretty good considering it's on at all times.

*The downside is that the app will not sync any data from your Flex unless you're connected to the internet. If you don't have connectivity, don't even bother opening the app.
*If you're sweating, moisture will tend to build up between your skin and the inside of the band, regardless of how tight or loose you wear it.
AnonymityIsKing at REI on 09/09/2013

Negative Reviews:

Dead in less than 5 months

I really liked my Fitbit Flex despite a few shortcomings. I especially liked that I didn't have to remember to put it on in the morning. I could - and did - wear it all the time. I liked the fact that it synced with my iPhone and the website, loved the silent alarm, appreciated being able to tap to see how close I was to 10000 steps (1 light per 2000 steps) and that it buzzed when I reached that goal, and enjoyed the weekly step summary I received via email. I also liked the sleep tracking when I remembered to log my sleep.

In terms of shortcomings, it was somewhat bothersome to have to manually log sleep. I suspected the background Bluetooth syncing with the Flex was partly responsible for the poor battery life of my iPhone 5, so I turned off background sync, which seemed to have helped. Charging was also problematic at times. Unless the tracker was seated just right in the charging dongle, it wouldn't charge. A firmware upgrade seems to have helped with that or at least made it more obvious when it wasn't seated properly.

The biggest problem with my Flex is that it died after less than 5 months. Earlier today, I had it on the charger and it appeared to reach a full charge. Now it is completely unresponsive to anything I try, including all the troubleshooting suggestions on the Fitbit website. An Internet search seems to indicate numerous users have had this device fail on them after a short period of time, and reviews of Fitbit's customer service are mixed. All I can say is thank goodness I bought it from REI. I expect to be able to return it for a replacement with no hassles, and I sincerely hope that the next one does not die on me so quickly.

Would I still recommend this to a friend? Yes, but ONLY with a MAJOR caveat to buy it from a retailer with a great return policy, like REI.
seasonsturn at REI on 10/10/2013

Broke in 2 weeks or less

I bought the fitbit looking for something to shed light on my sleep patterns, as well as my activity patterns. I knew going in it wasnt going to count calories burned or anything accurately, but wanted a slight motivation to get up and move more while at work or between classes. Problem was my band broke, split on seam between pastic band and the LED window. Fitbit was quick to replace the band, but as soon as it arrived the device stopped working, it would no longer charge. While I had the device working it was also telling me I woke 20+ times a night (not at all accurate). The fitbit was nice for tracking how far I walked randomly through the day and had immediate feedback with the lights, and an easy to use food and water tracking system online and on my phone app, I find the jawbone up (what I got after the fitbit broke) to be much more accurate for sleep cycles, and just as accurate for distance (dog walks always match the GPS distance exactly). The jawbone takes a bit more getting use to and doesnt have instant feedback like the LED lights, but I also dont worry the thing will fall apart on me.
REI was great in issuing a refund for the defective fitbit, and fitbit themselves were quick to replace the band, but to have the band and device both break in less than 2 weeks of ownership was enough for me to give up on it.
askpiper at REI on 09/09/2013

Shoddy product

I received this from my wife as an anniversary present. I am an avid outdoorsmen and a cross fitter and she thought it would be fun to try and track how well we were doing. First time I set mine up not all the functions were working so I had to take it back. Then my wife's literally stopped working and we returned it for another. Then a few weeks later mine just stopped working, so with that we just returned them both. When they were working they were kinda fun but I don't know how accurate they were. I would kill it at crossfit and come home and it would tell me I had more steps to go. We also found that the menu was very limited as we do a Paleo diet and the only way to put anything in was thought the main website. There are other apps that my wife was able to connect to but I was not able to with mine.
I think if you are new to exercising and dieting this would be a fun way to try and get into the monitoring of how much you are moving around and what you are putting into your body.
I am really disappointed as to the durability and reliability of the product. To go through 4 units in a month is really poor.
Skimurse at REI on 11/11/2013

Needs major improvements

Just got home from REI and have spent 3 hours trying to set up the flex wrist tracker and aria. So many disappointments. It is way too difficult to set up... and if you are a windows user who has a Surface RT or windows phone - forget it. These devices are pointless. They wont sync and have a minimal poorly designed app (cant log anything) that is just so disrespectful to customers of the largest world wide platform. Additionally after finally getting it to sync with my desktop computer (meaning I will have to manually sync daily - again pointless and a pain)I tracked a few steps. I took 6 steps that then registered to be 65... I expected some inaccuracy but wow. So once fitbit has their stuff together, wakes up, and creates a workable platform with wireless sync for the rest of us - I just might consider it in the future.
AlexF at REI on 01/01/2014

loved it til it didn't work!

I was really looking forward to getting my fitbit, because I wanted to track my activity and sleep. But I had to return it after a week: while I found it pretty easy to set up, it wouldn't charge up properly, and wouldn't hold a charge. I got frustrated wearing the device to bed, apparently fully charged, only to find it had died in the night. I figure I'll wait til the next generation comes out, and hope that by then it'll be more reliable. I also think it would be great if the fitbit could more accurately measure activities like dancing or cycling--I want it to do the work of tracking, rather than me just telling it what I did (how accurate am I?? that's what the device is for!)
caf at REI on 08/08/2013

Worked great for awhile

This is a really cool device, so light, it is inconspicuous to wear. Worked well for a month. One of the prime reasons for buying was the sleep monitoring aspect. But a month after having it, it would not go into sleep monitoring. You have to tap it quickly to get it to go into sleep monitoring. It would indicate that it was doing so, but come morning, no data. It was cool to get validation that my sleep wasn't too good, and it was great to track my activities, but... So, I contacted the powers that be, and they kept thinking it was a power issue, which it wasn't, so I returned it. I like the idea, might need to wait a little for some better technology.
RexyBaby at REI on 09/09/2013

A disappointing activity tracker

I was hoping that this would be a convenient way to track steps. It was fairly easy to set up and to charge initially, but it did not reliably sync with either computer or iPhone. It also didn't seem to be tracking any steps at all. I tried all of the steps provided in the online help website, and even reset the unit as they suggested. Nothing seemed to correct the situation.
It's possible that I just happened to get a defective unit, but I have decided that the Fitbit Flex is way more trouble than it's worth. I'm going back to my ancient step tracker.
I'm thankful that I bought this from REI, which has such a great return policy!
CLAS at REI on 10/10/2013

Fitbit flex

The Flex's features might best serve someone concerned about their weight and who needs encouragement to move a bit more. For me, an avid calorie burner who is not overweight the reinforcement I receive, is well, not reinforcing. Further, the steps/miles I'm being rewarded for are inaccurate. I was hoping to use it to tally steps indoors or undercover, where a GPS wouldn't work, but it is so inaccurate it is all but useless. The sleep features are interesting. It would be helpful if you wanted to count calories and needed support for your weight loss efforts. I am disappointed with my Flex.
Biker Fred at REI on 08/08/2013


Got this for Christmas. Went walking and came back it said I only went 2.2 mile. I used my phone (Nike app) to track as well and it told me I did 4.1 miles. So I googled it and the fitbit was wrong. Did this several times with different distances and it was always wrong. bummer :( I was super excited about this too. Needless to say I have returned it. This to me is just a super expensive pedometer. :(
kledesma09 at REI on 01/01/2014

I would not buy this again

I bought this for my high school son who is trying to improve his health with the monitoring system. The wristband latch is a poor design, and it would come off while involved in some of his activities. It feel off at school (in a crowd) and it was lost. After only four days of use it detached by general use and was stolen. Not a good design. I will find another device.
Pcola at REI on 11/11/2013

Neutral Reviews:

Enjoyed using it until I lost it

I was speaking on a panel about the Internet of Things and thought it about time I bought an activity tracker since I cover them at work. (I'm a healthcare IT research analyst).

The Fitbit device was easy to set up and link to my PC laptop and iPhone. I enjoyed tracking my steps and sleep patterns for the approximately 2 weeks I owned the device. The mobile phone app was easy to use and I could watch my step count in real time if I had the phone in my hand. Helped me to strive for my goal of 10K steps a day a few times knowing I didn't have that many more steps to go. The sleep app was also interesting -- revealing how little sleep I was really getting.

Then I lost my Fitbit at the end of my business trip where I was on the IoT panel. Thus, I can't comment on whether battery life degrades over time or how well the band will stand up to regular wear and tear - both seem to be isses for some people.

I rated the Fitbit Flex a 3 because it can be difficult to put on, especially with one hand, and the clasp is not that secure. The Flex fell off once or twice but I noticed it on the floor or felt it coming off my wrist. The day I lost it was getting ready to leave my hotel so was walking back and forth to the car, the front desk to check out and around the room to pack. The hotel never found it. Now I wish I had written my phone number on the inside of the band. I had thought about doing this, but never got to it before I lost it.

I would recommend - but with some caveats about it being good for basic step tracking and that it could easily come off your wrist if you're not careful.

If Fitbit is reading this - please do something to improve the band and the clasp. Also, it seems wasteful to send both a small and large band. Why not package the bands in either large or small and send two different colored bands. I'm perfectly capable of figuring out my wrist size without havinging to try on both and then have an extra band that is useless to me because it's too small.
Natockete at REI on 10/10/2013

Enjoying it but could live without it.

It is very interesting to track my steps and sleep pattern as I have never done so. I have the app on my S4 and it is really easy to follow my progress on it. I rated it easy to use because of this but I also rated it hard to use. I had trouble getting the silent alarm to work and the "tap to start sleep mode". I was able to start and stop the sleep mode off of the mobile app though.

I have had it for about 7 weeks and I had trouble charging it up today. I think the charging cord is not working and I already need a new one. I could wiggle it and it would start charging until I moved it again. If I cannot get a new cord, I will just return it as 7 weeks is not long enough to start having problems. When it did charge, I was able to get 5 days out of it so I was happy with the battery life. I have emailed the company for help so we will see what that brings...
Lamarie at REI on 09/09/2013

Band drives me nuts

Handy pedometer, doubtful if sleep activity is accurate. The band drives me nuts. Not really a latch, but press-fit of two lugs through two slits. Unless you get help, many folks won't be able to single handedly squash the lugs through the holes. If the lugs were round it would be easier, but they are oblong and must fit exactly in the slots. After a month of use, the band has not gotten any easier. Once on, though, you can keep it on for days unless you go swimming. I like the syncing and the web site is very handy for tracking your stats. Much better than old belt clip pedometer.
Dave1117 at REI on 12/12/2013

Consider Fitbit One which has altimiter

Had a Fitbit One loved it but lost it. Got Flex to replace it because harder to lose. But REI shopping comparison tool does not indicate that Flex vs One has no altimiter (that counts "stairs climbed") which for me is essential because I am a cyclist and "stairs climbed" x 10 = feet gained and that's an important metric. The display is also inferior showing only progress dots instead of info like time of day and calories burned. Fortunately I found my One and gave the Flex to someone who likes it a lot.
Peter D at REI on 07/07/2013

Works as advertised but died in 5 months

I purchased this for my wife as a birthday gift. She loved it right away. She is not a techie so she appreciated its ease of use, out of the box. The bluetooth syncing works well with the iPhone 5, and the app is very useful. However, the big minus is that the device started having problems at 4 months, and just died after 5 months. It stopped powering "on". My wife just obtained a replacement, but there is no way this product should die in such a short period of time.
dadccc at REI on 11/11/2013

Fitbit Flex troublesome

I particularly like the sleep monitoring function of the product. I wish it was waterproof rather than water resistant. It is extremely difficult to attach to the wrist. Mine has fallen off several times. It is attached by pushing two posts through the holes on the rubber band. This is very difficult to do and requires a lot of sterngth in your fingers.
robertb150 at REI on 01/01/2014

Fun but...

I bought 5 for Christmas and 2 have become unclasped and lost. The clasp isn't very good especially if you are active which are the people this is made for.
Sue iowa at REI on 01/01/2014

Came off too easily

Great usefulness for sleep patterns.
pammcpat53 at REI on 01/01/2014