Which Fitbit Should I get? Fitbits compared – One Vs Flex Vs Zip Vs Flex Buying Guide

We’re sat here in late 2015, with the pandemonium of black friday and cyber monday just around the corner, and we’re told that Fitbit sales are surging 168% as we rocket through Q4. Make no mistake, Fitbit are now mainstream, having broken through the upstart start-up phase, and having established themselves as one of the players in the fit-tech, fitness band, smart-tech and wearable space they’re now at a pivotal stage in their development. They have stacks of products on offer, ranging from activity trackers like the Fitbit Zip, through to smart scales like their Aria wifi’s and also now, including smart watches. This stage of their development is key though, as increasingly bigger tech brands, like Apple, are playing in their park, forcing them to raise the bar. Just the other week we concluded that the latest Asus offering beats the Fitbit Surge 2, and suddenly it struck us. Fitbit have metamorphosed from being a simple to read, streamlined and simply delineated and thus differentiated fitness band maker, to a complex hardware company playing in the bog leagues. We thought it was time to demystify their range, and to provide our loyal BurnTech readers with the definitive holiday season Fitbit buying guide. In this article, we’re aiming to answer the question “which Fitbit should i get”, by looking at the use cases across their ‘everyday fitness’ range and which model should appeal to which user. Without further fluff, lets dive in.

The review process

Michael Homestead is a fitness nut, who has personally tested nearly every fitness gadget that’s ever launched – including road testing every fitness band produced by Fitbit. He has followed the emerging fitness gadget revolution since the start, launching Burntech.tv in early 2013 to cover the space. The entire premise of this site was to look at fitness tech that helps us burn the calories and to get into better shape faster. For this detailed overview, he has also recruited staff writer Jennie Hepworth.

A look at the Fitbit product line

If you have gotten to this article, we’ll assume that you at least have a passing interest in the fitness tech offered by Fitbit. However, by now you may have done some research and you have therefore likely discovered that they have a fairly extensive product range. There’s the Zip which represents a simple activity and sleep tracker, the Surge, the Flex and the Charge. Many of these are into the second or even approaching their third generations, and all of this equals choice. And lots of it.

As of today, Fitbit have six live and being sold activity trackers, plus two which have been discontinued (The Force and the Ultra). The entire Fitbit product range can be found here on their official site, and is broken down into the three categories outlined below:

  1. “Everyday Fitness products” – including the Zip, One, Flex and Charge
  2. “Active fitness products” – The Charge HR
  3. “performance” – The Surge

In this buying guide, we’re only looking at the everyday fitness range. These are basically the bands which are focussed on the activity that we do outside of our training. Its certainly not to say that we shouldn’t use them in the gym, or whilst running or cycling, its just that their focus is on helping us to better understand our lifestyle and to make optimising it [for better health] easier.


Fitbit Zip

fitbit zip

Selling point: This is the companies entry level tracker, and is therefore a fun, simple yet basic way to begin tracking your daily activity score.


  • Its a highly affordable price, coming in at £49
  • It offers all of the expected tracking functions, including how many active minutes you have per day, how many steps you take and how far you go. If you’re new to activity tracking, this is ticking a lot of the must have boxes at a great price
  • Its a clip design – so you don’t have to have the device on show. This is a pro for me, but some see it as a con, as increasingly these devices are seen as fashion accessories.
  • Its water proof, so you can take it swimming.
  • Its got an easy to read display, which lets you clearly see what you have achieved today
  • Long life battery, which lasts around half a year, and is replaceable, so no charging needed


  • No backlight on the screen, which can retard your ability to read it in certain tough conditions. Other Fitbits have infinitely better screens, but yet they cost more, so take this or leave it, but you won;t be reading it in the dark.
  • Lacks the more sophisticated tracking, such as stairs climbed
  • The clip on design, its not attached to your wrist, so losing it is a very real (as i found out) possibility.

Who’s it for? In mine and Jennie’s opinion, this is your kick off Fitbit. Its ideal if you have never used such a device before, and as a result it offers a solid introduction to the idea of using technology to track your activity. he downside is that you may well find that you will end up graduating quite quickly if you like it, which leads you with the challenge of trying to decipher just how much you’ll like it BEFORE you buy it, as it could end up been $60 wasted (if you upgrade).

Fitbit One

fitbit one

Selling point: An upgrade on the Fitbit One, by adding in sleep tracking and other sleep tools – a vital component to overall health


  • At £79, it remains a highly affordable fit-tech tracker solution
  • Sleep tracking – which helps you understand your own sleep behaviours better, is a very nice to have feature upgrade on the Zip. When you go to sleep, you go through a number of stages of sleep, which includes the falling asleep stage, the rapid eye movement or dreaming phase, and the waking up phase. In between you’re in light sleep or go through phases of being awake during the night. Understanding this can help you cut back on the overall time in bed whilst also waking up more refreshed, which for many people is the dream – no pun intended! The One offers this, and visually illustrates it in the app.
  • Silent wake up alarm buzzes and vibrates to wake you up – which many people find to be a much nicer experience than being awoken by a loud alarm clock. If you’re really serious about improving your sleep though, read our guide to six bits of technology which will make you sleep better. This includes the Philips WakeUp light alarm, which plays ball brilliant with the One’s silent wake up feature. Otherwise the NuYu sleep solution is sheer genius as it also controls the temperature of your bed to help you sleep better.
  • The tracker is also upgraded, adding in the floors climbed feature which was missing on the Zip.


  • I personally find the design to be a bit weak on this model. Again it is clip on, and again this has its pros and its cons.
  • Its only available in two colours, black and pink.
  • The OLED screen – a definite upgrade on the Zip’s – is still tough to use in specific conditions, most markedly, in this devices case, in bright sunlight.

Who’s it for? Those who like the idea of sleep tracking and want some additional sophistication in the tracking – but who are not ready to commit to wearing such a device on their wrist. Its therefore more discrete, and in our opinion, its a no-brainer upgrade on the Zip.



Fitbit Flex

Check out this Fitbit Flex review of the original Flex.

fitbit flex

Selling point: A more fitness orientated activity and sleep tracker, which is a fashion statement that you proudly wear on your wrist.


  • This wrist worn tracker can be stylised with a range of accessories, and is available in a whole bunch of different colours.
  • Its fashionable – the Fitbit Flex is perhaps coming to epitomise the fashion movement around Fitbit’s and trackers in general. Its sleek and low profile, yet also makes a statement – ‘I care about my health and fitness’. The in-vogue thing to be seen wearing in chic world cities like NYC and London.
  • Great goal setting and visual representation – set your daily goal and then go off and achieve it. The Flex will clearly show you your progress and will nudge you into doing more. The premise of the tracker delivered, and it does this much much better than either the One or the Zip, as they’re hidden in your pocket.
  • Its easier to track everything when the device is connected to you, and you can even wear it in the shower.


  • Strangely, considering this is the first in the Fitbit line to be wrist-worn, it does not contain a clock (unlike the Zip and the One). Whilst a clock is not really what your paying £79 for here, it is a handy thing to have on your er, wrist.
  • There isn’t actually step counting [visually shown] – you simply get LED progress bars that kick into life when you get 20% closer to your daily goal. Therefore not good for the truly analytical amongst us.

Who’s it for? The fashion conscious user, looking for a device which makes a statement as much as it gives you hard (or otherwise) facts



Fitbit Charge

fitbit charge

Selling point: An advanced tracker which help you energise and inform your daily activity with more meaningful data points


  • A radically bigger feature set, which for an extra £20 is worth the upgrade. The highest and most spec’d product in Fitbit’s everyday health range aimed at non-gym and exercise specific use
  • Auto sleep detection – the device has a much better sleep toolkit than any of the other everyday health bands in the Fitbit range. This feature makes the sleep tracking meaningful, and is worth the upgrade alone IMO.
  • It has all of the advanced measurability offered by the other devices, like floors climbed and full sleep tools
  • Its wrist based, and has the strongest designs of any of the Fitbit everyday range.
  • It adds smartwatch lite features like caller ID, which works via bluetooth.
  • Strong battery life, and available in four colours


  • It is not water resistant, so this adds in tracking challenges. I find this one hard to understand considering the Flex has it.
  • Set up is quite a pain, considering the bluetooth and smartwatch-esque features.

Who’s it for? The upgrade on this is in the fitness range, which we will cover later this year, is the Charge HR, which offers all of these features plus heart rate monitoring – the new frontier for bands. I would personally pay the £20 more for that. Fitness bands tracking your heart rate through your wrist has its accuracy problems, as we investigated here, but its a nice to have.

So there we have it, the Fitbit range of trackers compared in one extensive buying guide. If you’re still struggling to decide between them, check out our guide to the five best tracker on the market today