Fitbit currently sells seven activity tracker wristbands – the Fitbit Ace, Flex 2, Alta, Alta HR, Charge 2, Versa and Ionic – and one clip-on activity tracker: the Fitbit Zip. That's a great but confusing range, and the company has replaced its older Surge and Blaze trackers with its new smartwatches - read our Fitbit Ionic review and Fitbit Versa review - that compete against the Apple Watch and others.

Activity trackers can motivate you to exercise more or improve your sports and fitness regimes. Even moderate exercise can have a positive effect on your physical and mental health. Buying one is a wonderful way to commit to a new year's resolution to get more healthy and fit.

Like Hoover and vacuums many people regard all activity trackers as "Fitbits" but there are other makes so be sure to read the best activity trackers currently available to buy too. Fitbit is by far the market leader, and has quality trackers for most people.

Super-serious sports, running and fitness fanatics – for whom even the new Fitbit Ionic or Versa aren't sophisticated enough – may prefer the more expensive top-end Garmin or TomTom trackers, which focus on specific sports such as running, cycling or swimming. 

If you're simply looking for the best Fitbit deals, you'll find out pick of the best right here. Continue reading for our buying advice that will help you find the Fitbit that will best suit your needs.

Which Fitbit is best for you?

Here's a brief function summary, before we go into more detail about features, price, battery life and more. 

  Ace Flex 2 Alta Alta HR Charge 2 Versa Ionic
RRP £79.99 £69.99 £99.99 £129.99 £139.99 £199.99 £299.99
Shop at Fitbit Pre-order Buy Buy Buy Buy Pre-order Buy
Steps, Calories & Distance Y Y Y Y Y Y Y
Floors Climbed - - - - Y Y Y
Clock/Time Y - Y Y Y Y Y
Sleep Tracking & Silent Alarm Y Y Y Y Y Y Y
Sleep Stages (Light, Deep, REM) - - - Y Y Y Y
SmartTrack - Y Y Y Y Y Y
Reminders To Move Y Y Y Y Y Y Y
Swim-proof - Y - - - Y Y
Multi-Sport Tracking - - - - Y Y Y
PurePulse Heart Rate - - - Y Y Y Y
Cardio Fitness Level - - - Y Y Y Y
Onscreen Workouts - - - - - Y Y
Built-in GPS - - - - - - Y
Connected GPS - - - - Y Y -
Call & Text Notifications Calls Y Y Y Y Y Y
Calendar Alerts - - Y Y Y Y Y
Popular Apps - - - - - Y Y
Stores Music - - - - - Y Y
Makes Payments - - - - - Y Y
Music Control - - - - - Y Y
Guided Breathing Sessions - - - - Y Y Y
Fitbit Accessories Y Y Y Y Y Y Y
Designer Accessories - Y Y Y - Y -

The clip-on Zip offers the least features but is great if you don't want to wear a wristband. We do worry that it is easier to lose than the wristbands, though. 

I like to first distinguish the wristbands by certain physical and functional features:

Pop-clasp straps: Flex 2 and Alta. These are the slimmest Fitbits, with the Flex 2 measuring 1.12cm wide and the Alta 1.55cm wide.

Watch-buckle straps: Ace, Alta HR, Charge 2, Blaze and Ionic. We prefer the more secure buckle-type straps as they are less prone to slipping off the wrist. At 1.55cm wide the Alta HR is still as slim as the Alta. The Charge 2 is 2.13cm wide, but therefore benefits from a larger stats display.

Heart-rate monitors: Alta HR, Charge 2, Versa and Ionic. Special LEDs on the underside of the wristband detect blood volume and capillary-size changes under pressure, and therefore measure your hear rate. Chest-strap heart monitors are more accurate, but uncomfortable and much less convenient. Measuring heart rate optimises exercise, helps you reach weight loss goals, track fitness and even manage stress. It also makes Fitbit's sleep analysis much more interesting, showing Deep, Light and REM sleep stages.

Colour screens: Versa and Ionic. The Versa is 2.4cm wide, and the Ionic 2.9cm wide. Both feature colour LCD touchscreen displays for better stat display and access. The Ionic is also less deep than the Blaze.

Onto the features and functions. The watch-buckle Charge 2, Versa and Ionic 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 Alta HR boasts the watch buckle but not the altimeter for Floors Climbed. We prefer the watch-buckle clasp as it's stronger than the pop-clasp, and are delighted that Fitbit chose this for its kids' tracker read our Fitbit Ace review.

The slimmer pop-clasp Flex 2 and Alta wristbands aremore chic, and (like the Alta HR and Versa) arguably aimed at women - although there's nothing in these designs to put off men. However, neither Flex 2 nor Alta has an altimeter, a heart-rate monitor or multi-sport functions. The Alta HR is similar but boasts the watch buckle and heart-rate monitor, so is worth considering - even at the slightly higher cost.

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's minimalist display, but think the Alta's more info-rich display gives you more data right there on the wrist. In some ways the Alta HR is the best of both world's, being super slim but still having the heart-rate monitor.

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 activity buzz is a great way to know you’ve reached your key target. Is that worth the extra cash for the Flex 2? That’s really up to you.

When it comes to choosing between the five Fitbit watch-buckle wristbands it's really a matter of price vs features. The top-end Ionic, with its built-in 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, tell you the time, and send you call/text/calendar notifications.

But the multi-sport functions and smartphone-connected GPS connectivity of the Charge 2 and Versa 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 Alta HR misses some sports features but is the slimmest heart-rate monitor you can wear on your wrist.

The colour touchscreen Fitbit Versa and Ionic trackers class themselves as smartwatches, as they can be customised with third-party apps. Both will appeal to those people who want an activity tracker but also a watch-like timepiece. Their colourful displays are also going to attract attention. The Versa is cheaper but the Ionic has the built-in GPS. Fitbit thinks the Versa's smaller size will appeal to women more than the larger Ionic, but both are unisex designs.

Your buying guide for the best Fitbit in 2018

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. 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.

How much should I spend?

Let's start with a key factor: cost. None of the Fitbits are pocket change like the Xiaomi Mi Band, but we've listed the best prices for each Fitbit below. You can also order direct via the Fitbit Store, where you'll get free delivery, a 45-day money back guarantee, and 2-year warranty.

Although it's been discontinued for a year (replaced by the superior Charge 2) the now venerable Fitbit Charge HR can still be found online at discounted prices. We've seen it on Amazon for less than £70. Its display is limited and you don't get any on-wrist call or text notifications but it remains a decent tracker choice.

For more detailed reviews of each model, see our full reviews, listed below.

Fitbit Zip review  |  Fitbit Ace review  |  Fitbit Flex 2 review   | Fitbit Alta review  |  Fitbit Alta HR review  |   Fitbit Charge 2 review  |  Fitbit Versa Review  |  Fitbit Ionic review

How do they compare on features?

The cheap clip-on Fitbit Zip lacks the sleep tracking and silent wake alarm found on the other trackers. And it doesn't buzz when you hit your Steps goal. It also doesn't feature a heart-rate monitor, or the sports functions and notification alerts.

For kids below the age of 13, the Fitbit Ace is a superior starter tracker. It's recommended for children aged 8 up, and there are special Parent and Kid views, plus family challenges and virtual badges to be won. Its strap is smaller than even the Small size options with the other trackers, but we found the other Fitbits to fit a child's wrist just as well. The Ace can be customised with straps for the Alta and Alta HR. While it's in Fitbit's terms and conditions that children aged under 13 should use only the Ace, there are plenty of kids out there wearing other models - parents just need to set-up the child's account using an older birth year.

The cheapest Fitbit wristband is the Flex 2, but this lacks some features of the more expensive Fitbits, such as an altimeter to measure "floors climbed", multi-sport functions, heart rate, Caller ID, text notifications and GPS tracking. But casual users don't really need the heart-rate monitor or sports capabilities, and only the top-end Ionic actually boasts a built-in GPS anyway. With the Versa and Ionic, the Flex 2 is also one of only three swim-ready Fitbit trackers.

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 from you but not in your pocket or in Silent mode then that little vibration alert that a call is incoming can be super handy. The Alta is a good deal if the heart monitor and sleep tracking aren't important to you.

If you do jog, run or exercise in any way as well as walking we think that it's worth paying for the extra heart-rate-monitoring functionality you get with the Alta HR, Charge 2, Versa and Ionic. Monitoring heart rate can also be used if weight loss is one of your key goals. But if you're just interested in everyday exercise the Fitbit Flex 2 or Alta will suffice, and are excellent trackers. The heart-rate function also gives you more detailed Sleep analysis - see later on for more details.

We also prefer the watch-buckle strap found on the Alta HR, Charge 2, Versa and Ionic. It feels more secure, and again is worth the paying extra for. If you want a wide range of straps and other accessories the Flex 2 has the most options, including a bangle and pendant, but the Alta, Alta HR and Versa also boast a large array of accessories, and you get plenty of options with the Charge 2 and Ionic.

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.

If you're looking for weight tracking, then check our our Fitbit Aria 2 review. These scales sync with the trackers to add measurements of your weight. There are also other good smart scales to buy. Fitbit has also announced a new Aria 2 smart scale.

Which trackers have these features?

All Fitbits have an accelerometer that measures motion patterns to determine your calories burned, distance travelled, and steps taken. (The Fitbit Ace does not show calories burned, as Fitbit doesn't want to add to a child's weight anxiety issues.)  All but the Zip also monitor sleep quality.


The Flex 2, Ace, Alta, Alta HR, Charge 2, Versa and Ionic also contain a vibration motor, which allows it to vibrate when alarms are set to go off. 

Floors climbed

The Charge 2, Versa and Ionic boast an altimeter that measures stairs (or height) climbed. Despite its name the Alta does not include an altimeter.


The Fitbit Ionic boasts eight sensors, and is the only model in the lineup to have GPS built in without the need for a smartphone to be linked. Users can see distance, pace and elevation climbed, and review routes and split times. The Charge 2 and Versa can connect to the GPS on your smartphone.

Heart rate monitor

The Alta HR, Charge 2, Versa and Ionic monitor your heart rate on your wrist. They use Fitbit's PurePulse technology that gives continuous, automatic, wrist-based heart rate, plus simplified heart-rate zones.

Additionally the Charge 2, Versa and Ionic feature Cardio Fitness Level, which provides a snapshot of your cardiovascular fitness. Based on estimated VO2 Max – calculated by your user profile, heart rate and exercise data – you can see how your fitness level relates to others of the same age and gender, and get guidance on how to improve over time.

The Versa and Ionic can also monitor the amount of oxygen in the blood (an important health indicator) with their Sp02 sensor.

Caller ID and text messages

The Ace, Charge 2, Alta, Alta HR, Versa and Ionic will all show Caller ID when linked to a smartphone. All the wristbands except the Flex 2 and the Ace also display text notifications on its display, and the Versa and Ionic allow you to control your music from the touchscreen display - each being able to store up to 300 songs on the watch. 

Automatic sport recognition

The Alta, Alta HR, Charge 2, Versa and Ionic feature multi-sport exercise tracking. They 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, and log the workout in the Fitbit app along with an exercise summary.

Reminder to Move

This is available on all the wristband Fitbit trackers. It 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. And they won't wake you at night!

Sleep tracking

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. Fitbit's new Sleep Stages measurements (on Alta HR, Charge 2, Versa, and Ionic) utilise heart-rate variability to estimate the amount of time you spend in Light, Deep and REM sleep, as well as time awake each night, to better understand your sleep quality. This is one of the great benefits of a tracker with a heart monitor, and sleep is now recognised as a major health metric.

The Charge 2, Versa and Ionic offer Relax Guided Breathing sessions that can help calm your body and mind through two- and five-minute sessions personalised to your breathing rate. The benefits of guided breathing practice are supposed to help reduce stress and anxiety, as well as lower blood pressure. Add it to your daily routine, and you'll quickly feel the benefits.

Which has the best display?

The Zip display has five modes: Steps; Distance; Calories burned; Fitbit Smiley (highlights your recent activity level); and Clock.

Fitbit Zip display modes

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.

Fitbit Flex 2 display

The Fitbit Alta and Alta HR take a longer, vertical view of its displays, and show much more information than the Flex 2.

Fitbit Alta displays

The Fitbit Ace shows the same stats as the Alta, minus Calories Burned.

Fitbit Ace active minutes

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.

Fitbit Charge 2 displays

The Versa's colourful touchscreen display is even better for visual display of fitness stats.

Fitbit Versa screens

The Ionic's larger display (below) shows even more data to fitness and sports nuts. Like the Versa, its display is a touchscreen colour LCD. You can choose from 17 different clock faces, and watch (and listen to) guided exercise workout training sessions.

Ionic screens

Which has the best battery life?

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 models have rechargeable batteries. Here's roughly how long each lasts between charges:

Zip: 4-6 months

Flex 2: up to 5 days

Ace: up to 5 days

Alta: up to 5 days

Alta HR: up to 7 days

Charge 2: Up to 5 days

Versa: up to 4 days

Ionic: Up to 5 days (will reduce depending on use of GPS)

Which Fitbits are water resistant?

The Flex 2, Versa and Ionic trackers are officially sanctioned as waterproof (down to 50M), and have basic swimming tracking features (number of lengths, distance swam). Experts recommend that you don't wear it while bathing, snorkelling or scuba diving, and Fitbit calls them water resistant rather than properly waterproof. (Note that accessory straps on the Versa and Ionic might not all be waterproof.)

Sadly none of the other Fitbit activity trackers can monitor your swimming, and Fitbit says you should not swim while wearing them. However, they won't immediately break if they get wet. I've accidentally jumped into a pool with one, and it was fine afterwards.

The Zip is just splash proof, while the Alta, Alta HR and Charge 2 are water resistant to 1 ATM (Atmosphere), so theoretically can be submerged up to 10 metres (33ft).

If you need something to monitor your aquatic efforts, then check out our round-up of the best trackers for swimmers.

Do they all use the same Fitbit app?

Yes. They all use the same iPhone, Android and Windows Phone apps. You can also see the data on Fitbit's desktop website.

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. It's here that Fitbit really beats its activity-tracking rivals.

The desktop dashboard is another visually attractive and informative place to monitor your activity and fitness statistics.

And as an 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 Adventures, and win badges determined by passing goals, and historical milestones. These aspects of the Fitbit system really set it apart from the other trackers.

Fitbit mobile app

Which colours are available?

The Fitbit Zip is available in either Charcoal or Magenta.

Fitbit Zip colours

The Flex 2 wristband is available in four colours: Black, Lavender, Magenta and Navy Blue.

Fitbit Flex 2 colours

You can buy extra bands for the Flex 2 (without the tracker) in packs of three for £24.99 / $29.95.

Fitbit Flex extra band packs

The kids' Fitbit Ace is available in two colours: Electric Blue and Power Purple.

Fitbit Ace colours

The Fitbit Alta is available in a classic strap (which comes with the tracker but you can buy extras for £19.99 or US$29.95 each) in Black, Blue, Plum or Teal; in leather (an extra £39.99/$59.95) in Graphite or Blush Pink); or in Stainless Steel (extra from £69.99/$99.95).

Fitbit Alta colours

The Fitbit Alta HR is available in a classic strap (again included but available as extra colours for £19.99 or US$29.95) in Black, Blue Grey, Fuchsia or Coral; in leather (extra £39.99/$59.95) in Lavender, Indigo or Brown; or in Stainless Steel (extra £69.99/$99.95) or Gold Plated (extra £109.99/$129.95).

Fitbit Alta HR colours

The Fitbit Charge 2 is available in its Classic Band model in Black, Plum, Blue and Teal.

Fitbit Charge 2 colours

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. These cost an extra £20/$30 on the standard models.

Fitbit Charge 2 Special Edition and Leather

The Fitbit Versa is available in a classic strap in Rose Gold watch case and Peach strap, Black case and Black strap, and Silver case and Grey strap. The Special Edition is available in Graphite Aluminium watch case and Charcoal woven strap, and Rose Gold Aluminium and Lavender woven strap.

Fitbit Versa colours

You can also buy stainless steel bands for the Versa, in Mesh (£69.99 / $79.95 / €79.95) and Links (£89.99 / $99.95 / €99.95) models.

Fitbit Versa metal Mesh and Links

And there are leather straps for the Versa, too - in Lavender, Saddle Stitch, Brown Cognac and Midnight Blue - at an extra £49.99 / $49.95 / €59.95.

Fitbit Versa Leather strap colours

The Fitbit Ionic is available in three Classic colours: Charcoal/Smoke Grey; Blue-Grey/Silver-Grey; and Slate-Blue/Burnt-Orange. You can also buy three £24.99/$29.95 Sport bands (Black & Charcoal; Cobalt & Lime; and Coral & Blue-Grey) and two £49.99/$59.95 Leather bands (Cognac; and Midnight Blue).

Fitbit Ionic colours