Fitbit currently sells five activity tracker wristbands – the Fitbit Flex 2, Alta, Charge 2, Surge, and Blaze – and two clip-on activity trackers: Fitbit Zip and One. Which Fitbit is best for you? Which Fitbit should you get? We explain all in the buying guide to the Fitbit activity trackers. Fitbit trackers compared and features in detail.
There are other activity trackers, of course, so be sure to read the best activity trackers currently available to buy too.
This feature has been updated to include the new Fitbit trackers: the Flex 2 and Charge 2, announced in August 2016. The Fitbit Charge HR, has been replaced by the Charge 2. The Flex 2 replaces both the Flex and the non-HR Charge tracker, so we've removed all of those models from this round-up.
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See also: Best Fitbit deals
Which is the best Fitbit: How to choose an activity tracker
Choosing the best Fitbit for you will come down to features and price, but you should also consider size, battery life and of course looks.
For more detailed reviews of each Fitbit activity tracker go to our dedicated review pages, listed below.
See also: Fitbit vs Apple watch
Which Fitbit is best: price
Let's start with a key factor: cost. None of the Fitbits are pocket change but none are horrendously over-priced either. You'll find cheaper variations online and in supermarkets but there are several advantages to buying a quality tracker. And if you start walking more you can make the money back quite quickly by not taking the bus, tube or train. I saved £100 in around two months, and got fitter into the bargain.
Click on these links below for the latest, best prices from Amazon. The latest Flex 2 and Charge 2 trackers are not yet available via Amazon, and must be ordered or pre-ordered via the Fitbit Store.
Fitbit Flex - £79.99 / US$99.95 - click here to view today's best prices on Amazon.
Fitbit Alta - £99.99 / US$129.95 - view today’s best prices on Amazon.
Fitbit Blaze - £159 / US$199.95 - view today’s best prices on Amazon.
Fitbit Surge - £199 / US$249.95. - view today’s best prices on Amazon.
If price is important you may be better off trying the clip-on Fitbit Zip or Fitbit One instead. The One costs the same as the Flex, but, as we’ll see, offers more features.
Fitbit One - £79.99 / US$99.95 - view today’s best prices on Amazon.
Fitbit Zip - £49.99 / US$59.95 - view today’s best prices on Amazon.
The cheapest Fitbit wristband tracker is the Flex 2, but this lacks some of the features of the more expensive Fitbits, such as an altimeter to measure "floors climbed", multi-port functions, heart rate, Caller ID and Text Notifications and GPS tracking. But casual users don't really need the heart-rate monitor or sports capabilities, and only the top-end Surge actually boasts a built-in GPS anyway. The Flex 2 is also the only waterproof, swim-ready Fitbit tracker.
The Alta is one step up from the Flex 2, but quite a jump in terms of price. For the extra money you gain Caller ID and Text Notifications, which many will find very useful. If your phone is a short distance froim you but not in your pocket or in Silent mode then that little vibration alert that a call is incoming can be super handy.
If you do jog, run or exercise in any way as well as walking we think that it might be worth paying for the extra heart-rate-monitoring functionality you get with the Charge 2, Blaze and Surge. But if you're just interested in everyday exercise the Fitbit Flex 2 or Alta will suffice, and are excellent trackers.
We also prefer the watch-buckle strap found on the Charge 2, Blaze and Surge. It feels more secure, and again is worth the paying extra for.
Remember to factor in the cost of the straps and accessories to the price of the wristband trackers if you fancy something different to the included Classic bands. Having a choice of straps is appreciated, but it does make the pricing harder to compare.
You should find cheaper prices at the usual online retailers. Check each individual Fitbit review at the links above for the latest, best prices.
Fitbit also sells the Fitbit Aria smart scales, which sync with the trackers to add measurements of your weight, BMi and Body Fat Percentage. Read our Fitbit Aria review and also our Best Smart Digital Scales review.
Which Fitbit is best: features
The charts below shows all Fitbit features by device model, plus prices. Click on the image to make it bigger.
The cheaper clip-on Fitbit Zip doesn’t offer all the features found on the One, Flex 2, Charge 2, Alta, Charge HR, Blaze or Surge. For example it lacks the Sleep Tracking and Silent Wake Alarm found on the otehr clip-on tracker, the Fitbit One. Neither clip-on tracker features a heart-rate monitor, or the sports functions and notification alerts.
All Fitbits have a MEMS 3-axis accelerometer that measures motion patterns to determine your calories burned, distance traveled, and steps taken. All but the Zip also monitor sleep quality.
The One, Flex 2, Charge 2, Alta, Blaze and Surge also contain a vibration motor, which allows it to vibrate when alarms are set to go off. The soon-to-be discontinued Fitbit Charge HR offers the same functions as the Charge 2, except for multi-sports and GPS connectivity with a smartphone.
The One, Charge 2, Charge HR, Blaze and Surge boast an altimeter that measures stairs (or height) climbed. Despite its name the Alta does not include an altimeter.
The Fitbit Surge boasts eight sensors: 3 axis accelerometers, gyroscope, compass, ambient light sensor, GPS and heart rate. The Fitbit Blaze lacks the GPS, but does boast a smart colour touchscreen.
The Fitbits track seven days of detailed motion data – minute by minute, and daily totals for past 30 days. They store heart rate data at 1-second intervals during exercise tracking and at 5-second intervals all other times. The Sample rate for GPS is 1Hz.
The Charge 2, Charge HR, Blaze and Surge monitor your heart rate, and without having to lash sensors to your chest like some HR trackers demand. It's all done on the wrist. They use Fitbit's PurePulse heart rate technology that gives continuous, automatic, wrist-based heart rate, plus simplified heart-rate zones.
The Charge 2, Alta, Charge HR, Blaze and Surge will all show Caller ID when linked to a smartphone. All the wristbands also display Text Notifications on its display, and the Blaze and Surge allow you to control your music from the touchscreen display. We found call notifications very useful. You can rely on the wriststrap buzz more than your phone's vibration, and even see who's calling right there on your wrist, which is more polite than and easier than pulling our your phone when chatting to someone else. It's expecially handy when you're at home and your phone is in a different room where you might not hear it.
The top Fitbit wristbands (Alta, Charge 2, Blaze and Surge) feature multi-sport exercise tracking to easily record workouts and see real-time exercise stats and summaries. A recent software update means the Charge HR and Surge can now automatically detect which activity you're doing – and this functionality is also present on the Alta and Blaze. This means these trackers will know when you're cycling, running, hiking or playing sports including football, tennis and basketball. They will also recognise aerobic workouts such as Zumba, cardio-kickboxing and dance workouts. They will record the excercise in the Fitbit app along with an excercise summary.
All the Fitbit wristbands now boast a neat new feature borrowed from the Apple Watch. Using short exercise prompts the Fitbit encourages you to meet a mini-step goal of 250 steps each hour (approximately 2-3 minutes of walking). These prompts can be personalised to your schedule; for example they can be put on “Do Not Disturb” during long meetings or appointments. We love this feature, and hope Fitbit adds it to the other trackers soon.
Fitbit has added Hourly Activity and Stationary Time in the Fitbit app, when paired with Surge, Blaze, Charge HR, Charge 2, Alta, or Flex 2.
All the Fitbits, except the Zip, check your sleep, too. They measure the time you spend asleep and check the quality of sleep – noting when you are restless or wake up during the night. Increasingly sleep is regarded as a vital health factor. Runing around and eating well won't help you as much if you're sleep patterns are too short or restless. Poor quality sleep is also seen as a factor in heart disease, colds and infections, depression and lack of sex drive.
If losing weight is one of your aims then you should consider the Fitbit Aria, digital scales that wirelessly sync with your account and measure your weight, body fat percentage and BMI. But don't try wearing it on your wrist!
On top of all this the super-fitness-stats Fitbit Surge features GPS tracking, without the need for a smartphone to be linked. Users can see distance, pace and elevation climbed, and review routes and split times. This beats the Apple Watch, which relies on the GPS in your iPhone. The Blaze and Charge 2, like the Apple Watch, require a connected smartphone, but works not just with the iPhone but Android and Windows Phone too. While built-in GPS is great, most of us exercise with our smartphone on us for music and calls – so connecting to your phone's GPS isn't that much of a nuisance, and saves your trackers' battery. See New Fitbit trackers rumours and release date.
Here's how Fitbit lists each of the trackers' special features, starting with the Flex 2, below:
The Fitbit Alta features:
Now, the Charge 2 features:
Next, the soon-to-be-discontinued Charge HR (replaced by the newer Charge 2) features:
Then, Fitbit Blaze features:
And finally the Surge features:
Fitbit improvements: skin allergies and better clasp
Fitbit was bitten hard when it had to withdraw and recall its Force wristband when some owners reported developing a skin rash as a result of metal allergies. The company has employed scientific experts Dr Peter Schalock, an Assistant Professor of Dermatology at Harvard Medical School, and Dr Patricia Norris, Assistant Professor of Dermatology at Oregon Health & Science University, to make every effort to reduce the chances of Fitbit users having reactions from parts of their wristbands.
Fitbit still warns that “if you have eczema, allergies, or asthma you may be more likely to experience a skin irritation or allergy from a wearable device.”
It also advices that “if you sweat for more than two hours while wearing your Fitbit band, be sure to wash your band and your wrist using the directions above to avoid skin irritation.”
Each new wristband (except the Alta, Charge 2 and Blaze's leather and stainless steel wristbands) is made of a flexible, durable elastomer material similar to that used in many sports watches.
Another problem that beset Force owners was the wristband's weak clasp, which lead to many – me among them – losing their treasured tracker. Now take a look at the back of the Charge 2, and you'll see a surgical-grade stainless steel buckle that's much more like a standard watch. The new buckle is found on the Charge 2, HR, Blaze and Surge, but not the slimmer Flex 2 or Alta. Fitbit has improved the pop-in clasp found in the Alta and Flex 2, but it can still come undone. It's one of the reasons we recommend the watch-buckle Fitbits instead. Plus the buckle isn't uncomfortable when worn in bed.
Which Fitbit is best: display
The Zip display has five modes: Steps; Distance; Calories burned; Fitbit Smiley (highlights your recent activity level); and Clock.
The One’s display has six modes: Steps; Distance; Calories burned; Floors climbed; Flower (grows and shrinks based on your recent activity); and Clock.
The Flex 2’s display is the most minimal, consisting of a series of flashing dots that show you how your day is stacking up against your goals. Each light represents 20 percent of your goal. You just tap the display twice to see your progress against your daily goal. This is very easy to get used to but isn’t as informative as the other Fitbits. Of course you can see all your stats via the Fitbit iPhone or Android smartphone app.
The Fitbit Alta takes a longer, vertical view of its displays.
The Charge 2's OLED display (below) shows Time; Steps; Heart Rate; Distance; Calories burned; Floors climbed; Very active minutes; Caller ID; Text Notification; and Alarm.
The (soon-to-be-discontinued) Charge HR's OLED display shows Heart Rate; Exercise Tracking; Time; Steps; Distance; Calories burned; Floors climbed; Very active minutes; Caller ID; and Alarm.
The Blaze's colourful display wins hands down, although you won't see it if you put your hands down…
The Surge's larger display (below) shows even more data to fitness and sports nuts. Its display is a touch screen monochrome LCD with backlight (for low light visibility).
Which Fitbit is best: measurements and specs
While the Fitbit One and Zip are small and can clip onto clothing or sit in your pocket they’re in some ways less flexible than the wristbands. You’re also less prone to forget a fitness wristband than you are a tiny clip-on gadget which inevitably gets left behind when you change your clothes, and we've put several through the washing machine (amazingly, they mostly survived).
The Flex 2 and Alta are thinner and slightly lighter than the Charge 2. The Flex 2 is 13.99mm wide and the Alta 15mm, compared to the Charge's 21.1mm girth. As the Charge/HR/Surge also include a watch function they might actually save you wrist space as you can ditch your watch.
The Zip is the smallest of the Fitbits – it’s shorter than the One but podgier.
When you buy a Flex you get both a large (161-209mm) and small (140-176mm) wristband, but with the Charge, Charge HR and Surge you need to specify whether you want Small, Large or X-Large, as the tracker itself is built into the band. You choose a S, L or XL tracker for the Alta and Blaze, and can also choose an extra, different strap separately. You can check with Fitbit’s online wristband sizing tool.
Fitbit Zip size and weight: H: 48mm; W: 19.3mm; D: 9.65mm; Weight: 8g.
Fitbit One size and weight: H: 35.5mm; W: 28mm; D: 9.65mm; Weight: 8g.
Fitbit Flex 2 size and weight: W: 11mm; Weight: 23.5g (weight dependent on strap choice). This is the slimmest and lightest Fitbit wristband.
Fitbit Alta size and weight: W: 15mm. Weight dependent on strap choice.
Fitbit Charge 2 size and weight: W: 21.45mm; Weight dependent on strap choice.
Fitbit Charge HR (to be discontinued) size and weight: W: 21.1mm; Weight: 26g.
Fitbit Blaze size and weight: W: 42.1mm. Weight dependent on strap choice, but 43g with Classic Strap.
Fitbit Surge size and weight: W: 34mm; Weight: 52g.
Which Fitbit is best: battery life
Remembering to keep your Fitbit charged is important if you wish to keep your activity tracked. The longer the battery life in between charges the better, then.
The Zip is easily the best for battery life but you will need to buy a new battery two or three times a year. The 3V coin (CR 2025) battery is cheap, though – you can buy a pack of five for under £2.50 (US$3). The other Fitbits feature rechargeable batteries.
Remember that accessing the display on any of the Fitbits will drain the battery faster.
Fitbit One battery life: 5-7 days
Fitbit Zip battery life: 4-6 months
Fitbit Flex 2 battery life: up to 5 days
Fitbit Charge 2 battery life: Up to 5 days
Fitbit Alta battery life: up to 5 days
Fitbit Charge HR battery life: 5+ days
Fitbit Blaze battery life: up to 5 days
Fitbit Surge battery life: Up to 5 days
Which Fitbit is best: water resistance
Only the new Fitbit Flex 2 is actually officially sanctioned as waterproof, and has swimming tracking features.
Sadly none of the other Fitbit activity trackers can monitor your swimming. And none of the other Fitbits are happy getting wet. See: Is the Fitbit waterproof?
The Fitbit One, Zip, Alta, Charge2, Blaze and Surge are splash proof, but should not be submerged more than one metre.
The Flex 2 is water resistant to 50 metres, which is rated as 5 ATM (Atmospheres).
The Alta, Charge 2, Charge HR and Blaze are water resistant to 1 ATM (Atmosphere), so theoretically can be submerged up to 10 metres (33ft). However, watch specialists advice that a device with this resistance level is protected against accidental exposure to water; for example, splashes, perspiration or accidental immersion; and state that it should not be exposed to any water pressure. I did once jump in a swimming pool with my Charge HR and it survived, but it's not recommended!
The Fitbit Surge is water resistant to 5 ATM, which means it is wearable around household sinks, while playing sports and while swimming in shallow water. Experts recommend that you don't wear it while bathing, snorkeling or scuba diving, and Fitbit calls it water resistant rather than properly waterproof.
What's the best activity fitness tracker for swimmers?
Which Fitbit is best: colours
The Fitbit One is available in either Burgundy or Black.
The Fitbit Zip is more colourful, available in either Blue, Magenta, White, Charcoal or Lime.
The Flex 2 wristband is available in four colours: Black, Lavender, Magenta and Navy Blue.
From 2017 you can buy extra bands for the Flex 2 (without the tracker) in packs of three for £24.99.
The Fitbit Alta is available in a classic strap (extra £19.99 or US$29.95) in Black, Blue, Plum or Teal; in leather (extra £49.99/£99.95) in Graphite or Blush Pink); or in Stainless Steel Links (extra £79.99/$129.95).
The Fitbit Charge 2 is available in its Classic Band model in Black, Plum, Blue and Teal.
There are also Special Edition models of the Charge 2, available in Lavender/Rose Gold and Black; and Luxe Leather in Brown, Blush Pink and Indigo.
The (to be discointinued) Fitbit Charge HR is available in Black, Plum, Blue, Tangerine, Teal and Pink.
The Fitbit Blaze is available in a classic strap (extra £19.99 or US$29.95) in Black, Blue or Plum; in leather (extra £59.99/£99.95) in Black, Camel or Mist Grey); or in Stainless Steel Links (extra £89.99/$129.95).
The Fitbit Surge is available in three colours: Black, Blue and Tangerine.
Which Fitbit is best: what you get in the box
The Fitbit Zip ships with tracker, silicone and metal clip, wireless sync dongle, replaceable battery and battery door tool.
The Fitbit One comes with tracker, silicone and metal clip, wireless sync dongle, charging cord and sleep wristband.
The Fitbit Flex 2 includes removable tracker, wristband (one small and one large), and charging cable.
The Fitbit Alta ships with a removable tracker, Classic wristband, charging cable, and wireless dongle.
The Fitbit Charge 2 comes with tracker, wristband (either small, large or x-large), and charging cable.
The Fitbit Charge HR comes with tracker within wristband (either small, large or x-large), wireless sync dongle, and charging cable.
The Fitbit Blaze ships with a charging cable. You need to specify the type of band (Classic, Leather or Stainless Steel) you require.
The Fitbit Surge ships with tracker within wristband, wireless sync dongle, and charging cable.
All the trackers work with the excellent Fitbit desktop dashboard and iPhone, Android and Windows Phone apps.
The apps look wonderful, and display all your daily and historical stats in beautiful graphs that expand in landscape orientation as well as display in portrait view.
The desktop dashboard is another visually atrractive and informative place to monitor your factivity and fitness statistics.
And as added incentive you can link with friends, family and colleagues to compete against each other on the leaderboard, get involved in daily or weekly Challenges, and win badges determined by passing goals, and historical milestones. These aspects of the Fitbit system really set it apart from the other trackers.
Losing a Fitbit wristband
Some Fitbits are easier to lose than others. Obviously if you are the sort of person who puts things down and then forgets where they put them, then you'll expect to lose your possessions every now and again. But with Fitbits some are risker than others.
The Zip and One clip to your clothing or can be carried in a pocket, and so could be easier to mislay than something attached to your wrist. The wristbands are certainly less easy to lose, but we recommend you go for one with the watch-like buckle (Charge 2, HR, Blaze, Surge) as these are much more secure than the pop-in clasp (Flex 2, Alta) if you're concerned about losing it. The slimmer Alta and Flex 2 are undoubtedly more chic than the watch-buckle brigade, but not as secure on the wrist.
Which Fitbit is best for you?
Fitbit Flex - £79.99 / US$99.95 - click here to view on Amazon.
Fitbit Charge - £99.99 / US$129.95 - view on Amazon.
Fitbit Alta - £99.99 / US$129.95 - view on Amazon.
Fitbit Charge HR - £119 / US$149.95 - view on Amazon.
Fitbit Blaze - £159 / US$199.95 - view on Amazon.
Fitbit Surge - £199 / US$249.95. - view on Amazon.
Fitbit One - £79.99 / US$99.95 - view on Amazon.
Fitbit Zip - £49.99 / US$59.95 - view on Amazon.
It’s possible to look at the Fitbit activity trackers in three groups.
The clip-on Zip and One offer the least features but are perfect if you don't want to wear a wristband. We do worry that these are easier to lose than the wristbands, though.
The watch-buckle Charge 2, Charge HR, Blaze and Surge wristbands boast the most features, including Floors Climbed via the altimeter. They also show more right there on their displays, including Call and Text Notifications from your phone, including Caller ID.
The slimmer pop-clasp Flex 2 and Alta wristbands are mnore chic, and maybe aimed at women, although there's nothing in the design to put off men. Neither has an altimeter or boasts heart-rate or multi-sport functions. One solution is to own more than one Fitbit! You can sync multiple trackers to your Fitbit account, so maybe wear a fully featured sporty tracker during the day, and slip on a slimmer, more chic Alta or Flex 2 in the evening. We love the Flex 2 minimalist display, but think the Alta's better display gives you more data right there on the wrist.
The Zip is the cheapest Fitbit, and if you can live without the altimeter and sleep tracking then this is a great entry point. Sleep tracking is fun but not at the top of most people's fitness lists, but the buzz is a great way to know you’ve reached your key target. Is that worth an extra £30 for the One or Flex? That’s really up to you.
When it comes to choosing between the four Fitbit watch-buckle wristbands (soon to be three when the HR is dropped from the lineup) it's really a matter of price vs features. The top-end Surge, with its GPS, is the obvious choice for the serious fitness nut – or you can wear one, and pretend to be a performance fitness nut, and just use it to count your steps and tell you the time. But the multi-sport functions and smartphone GPS connectivity of the Charge 2 and Blaze should satisfy most fitness enthusiasts. Their lack of built-in GPS might disappoint some, but most runners take their smartphone with them for music or call, so their wireless connection to the phone's GPS does the same trick.
The Fitbit Blaze is similar to the other Fitbits but comes with a flashier colour display. It will apeal to those people who want an activity tracker but also a watch-like timepiece. Its colourful displays are also going to attract attention.
There's a Fitbit tracker for everyone. If you're unsure you can always later sell up and upgrade to a higher-spec Fitbit tracker. Getting fitter now is the main thing, so get started soon.