New year, new you, right? The start of a new year spurs many on in getting back into shape; setting themselves up for the coming months as fit and as healthy as possible, and fitness trackers are a perfect tool to support on such a journey.

Fitbit, specifically, makes some of the most well-respected trackers and fitness-centric smartwatches out there, not to mention, they're backed by a passionate and active community of users.

The company's current range of trackers and watches span a myriad of prices, feature sets and designs, meant to suit every budget, need and taste. 

Whether you simply want to track your steps pedometer-style, see how well you’re sleeping, monitor your heart rate or compete against your friends, a Fitbit is a subtle, affordable accessory. New health features look further into your heart and wellbeing, as well as stress levels and illness potential.

The latest Fitbit smartwatches can even facilitate calls right there on your wrist, and work with both Amazon Alexa and Google Assistant voice controls.

Owning a Fitbit is going to motivate you to exercise more, and even get a better night's sleep. We've tested every Fitbit ever launched and we're going to tell you which is the best Fitbit for you. We've even included some older Fitbits that have been discontinued but are still available from third-party retailers.

Find more in-depth buying advice below our chart.

Best Fitbits 2022


Fitbit Versa 3 - Best Fitbit smartwatch

Fitbit Versa 3
  • Pros
    • Top fitness features
    • GPS
    • On-wrist calls
  • Cons
    • Some features require Premium subscription

The Fitbit Versa 3 covers all the aspects of a fitness watch, measuring steps, heart rate, distance, calories burned, floors climbed, active minutes, hourly activity and sleep, with plenty of extra health features (such as SpO2 blood-oxygen readings), plus built-in GPS, for those who outdoor exercise without their phone.

It offers on-screen notifications from your phone, silent alarms, cardio fitness levels, workout and other exercise modes such as swimming and weights, female health tracking, and wellness features, plus music controls and Amazon's Alexa and Google voice assistant.

You can even take and respond to phone calls on your wrist, as it has a built-in microphone and speaker.

It matches the more expensive Fitbit Sense on all fitness features and most health functions, too. And its screen is just as large and bright.

While the Sense has more detailed health apps and sensors such as EDA, ECG and Skin Temperature, plus stress-management tools, we think these are over the top for most users, and the Versa 3 range of features is more than enough, and at a much better price. High and Low Heart Rate Notifications – which were previously an exclusive Sense feature – are now part of the Versa 3's wheelhouse too.

It's our favourite Fitbit, as it has a great screen and all the fitness features found in even the top-end Fitbit Sense.

Read our full Fitbit Versa 3 review


Fitbit Inspire 2 - Most affordable Fitbit

Fitbit Inspire 2
  • Pros
    • Affordable tracker
    • Fitness features
    • Location finder
  • Cons
    • Connected rather than built-in GPS
    • Monochrome display

The Fitbit Inspire 2's fitness feature set covers the basics very well: steps, calories burned, Active Zone Minutes, distance travelled, heart rate, advanced Sleep Stages measurement, swim tracking, guided relaxation breathing, the ability to auto-detect workouts with reasonable accuracy, and notifications. 

It lacks the built-in GPS found in the Charge 5, Charge 4, Versa 3 and Sense but will connect to your phone's GPS if you need location services for pace measurements. Sure, it also lacks an altimeter (so won't count the floors you climb), but otherwise is almost as capable as Fitbit's more expensive trackers

The heart-rate monitor deepens the device's exercise analysis and makes its sleep tracking far more sophisticated. If activity tracking is what you're after, the Fitbit Inspire 2 delivers in an affordable package.

At the moment, it's also the only Fitbit with integrated Tile location finding, if you mislay it.

It lacks the colour screen boasted by the Fitbit Luxe and Charge 5 tracker-style Fitbits, but offers greater value for money.

This is a great price for a light, smart-looking device with a solid feature set. Fitness fanatics will want something more advanced, such as the Charge 4, Charge 5, Versa 3 or Sense - but for most of us, the Inspire 2 will be all we need.

Read our full Fitbit Inspire 2 review


Fitbit Charge 5 - Best tracker-style Fitbit

Fitbit Charge 5
  • Pros
    • Top fitness features
    • GPS
    • Colour display
  • Cons
    • Occasionally laggy
    • Some Charge 4 features missing

The Charge 5 is easily our best all-round Fitbit activity tracker. Fitbit has cherry-picked some of the best and brightest features from its latest trackers and smartwatches to create a Goldilocks product that delivers an impressive breadth of functionality for the price, not to mention wrapping it up in a lightweight and stylish package.

It covers all the basics - tracking steps, distance, calories burned, hourly activity, heart rate, swim-tracking and advanced sleep, not to mention it has most of the top-end exercise features too, including Active Zone Minutes. Its built-in GPS means it's a tracker that can match the pricier smartwatches, though it can't take calls, like the Sense and Versa 3 can.

There are a few missteps, however, like inconsistent performance, awkward device management, no altimeter (which the Charge 4 offered) and a few previously-available features that simply weren't present on the Charge 5 at launch, when they really should have been.

Read our full Fitbit Charge 5 review


Fitbit Sense - Best Fitbit for wellbeing

Fitbit Sense
  • Pros
    • Top fitness and health features
    • GPS
    • On-wrist calls
  • Cons
    • Some features require Premium subscription

The Fitbit Sense sits at the top of the pile for the sheer number of features and stands out especially for its detailed health functions, and for its heftier price tag.

These include an Electrodermal Activity (EDA) sensor that can measure the intensity of emotion (important for stress management), Electrocardiogram (ECG) app to assess your heart for heart-rhythm irregularity, and a skin temperature sensor that can be used to indicate the onset of a fever or illness.

If the high-end health functions are less of a priority, the very capable Versa 3 may be a less expensive option for you, but the Sense still has the most features.

It boasts all the fitness features and smart apps found in the other Fitbits (and is more accurate at swim tracking with its gyroscope) and is the standout Fitbit smartwatch for health measurements and insights, although some readings require a Fitbit Premium subscription.

Read our full Fitbit Sense review


Fitbit Luxe - Most fashionable Fitbit

Fitbit Luxe
  • Pros
    • Top fitness features
    • Slim
    • Stylish
  • Cons
    • Connected rather than built-in GPS
    • Some features require Premium subscription

The stylish Fitbit Luxe is inspired by jewellery and created for its looks, as much as its features.

There’s even a Special Edition Luxe designed by jewellery brand Gorjana – with a Parker Link Bracelet in soft gold stainless steel, alongside a swim-proof classic silicone Peony band. There are also a wide variety of accessory bands for the Luxe.

This tracker isn’t all style over function though, as it includes a heart-rate monitor and all the supported fitness features, such as Active Zone Minutes, and with 20 exercise modes, from biking to Pilates.

The Luxe is a tracker, rather than a full smartwatch, and is closer to the entry-level Inspire 2 than the fuller-featured Charge 5. There’s no built-in GPS, for example, like you get with the Charge 4 and 5, although you can connect it to your phone’s GPS.

It lacks an altimeter to count floors climbed too, but it does at least show smartphone notifications, such as Caller ID and messages.

It's packed with wellness features, too, including stress management, Guided Breathing sessions and access to Health Metrics, such as breathing rate, heart rate variability (HRV), resting heart rate (RHR), skin temperature and oxygen saturation (SpO2).

Think of the Luxe as an Inspire 2 Deluxe Edition, with the same features but a slightly slimmer build in a stainless steel body and with a colour display.

Read our full Fitbit Luxe review


Fitbit Ace 3 - Best Fitbit for Young Kids

Fitbit Ace 3
  • Pros
    • Designed for kids
    • Parent and Kid Views
  • Cons
    • Lacks heart monitor
    • Less features than others
    • Monochrome

The Fitbit Ace 3 is designed especially for younger children. It's a well-priced if basic activity tracker. It lacks most of the more advanced health measurements that you’ll find on the pricier Fitbits but it has enough to motivate a family to up their exercise.

Until recently, children under 13 were not allowed to have a personal Fitbit account. Now the minimum age is 6  – as long as you use the Fitbit Ace 3, which measures Steps and Active Time, plus basic sleep monitoring.

Special family account features mean kids (and parents) can track their basic activity stats through secure Kid View and Parent Views; where they can see their progress, compete in challenges, and earn badges.

The Ace 3 is about exercise, not weight loss - Fitbit hides the calorie counter to stop children from obsessing about their weight.

Older kids might prefer a Fitbit that does more, such as measuring their heart rate. The Fitbit Inspire 2 might lack the Ace 3's wraparound silicone padding but it offers a big bunch of features, including exercise modes, Cardio Levels, Sleep Score, Guided Breathing and for just £20/US$20 extra, and we'd recommend this for older or more responsible children.

Read our full Fitbit Ace 3 review


Fitbit Charge 4 - Old but still got it

Fitbit Charge 4
  • Pros
    • Top fitness features
    • GPS
    • Slim
  • Cons
    • Monochrome display
    • Older model

The Charge 4 is still a great all-round Fitbit activity tracker, even if it has since been replaced by the Charge 5, with its full-colour display.

It still covers all the usual activity tracking, along with Active Zone Minutes, sleep recording and SpO2 readings, with a built-in GPS to improve its run-recording.

Choose the Charge 4 if you can live with the smaller, monochrome screen. Otherwise, consider the less-featured but more chic Luxe, or splash out for the Charge 5.

Read our full Fitbit Charge 4 review


Fitbit Versa 2 - Still a great option

Fitbit Versa 2
  • Pros
    • Top fitness features
    • Alexa
  • Cons
    • Older model
    • No calls on wrist

Replaced by the Versa 3, the older Versa 2 is still a great fitness smartwatch.

It has nearly all the features found on the Versa 3 but lacks built-in GPS; although it can connect with your phone's GPS. 

The Versa 3 claims more accurate heart-rate measurements, which could sway newcomers to the latest model, but probably not existing Versa 2 users.

It can work with Amazon's Alexa voice assistant, but not the Google Assistant, which is available to the Versa 3. It also lacks the ability to take calls on the wrist, another Versa 3 benefit.

If you find a Versa 2 at a great price, we still rate it as a great fitness smartwatch; not as great as the Versa 3 but only a couple of features behind.

Read our full Fitbit Versa 2 review


Fitbit Aria Air - Best Fitbit scales

Fitbit Aria Air
  • Pros
    • Syncs with Fitbit app
  • Cons
    • Other scales have more metrics

If you couldn’t care less about body fat percentage and other weight and body statistics, and just want your weight to be automatically synced to your Fitbit app, then the Fitbit Aria Air is the scale for you, and will save you a fair bit on the slightly more able Aria 2.

You also get your Body Mass Index (BMI), too, but nothing else.

If you want to dig deeper and monitor your body fat percentage and a raft of other metrics such as body fat percentage, water %, muscle & bone mass, then look at our other best digital smart scales reviews.

Read our full Fitbit Aria Air review


Fitbit Inspire - Discontinued but still available

Fitbit Inspire
  • Pros
    • Affordable
    • Slim
  • Cons
    • Older model
    • Lacks some features

Despite it being discontinued and replaced by the much more feature-filled Inspire 2, we'd happily recommend the Fitbit Inspire to a casual fitness enthusiast, since it's affordable, smart-looking and easy to use. And, of course, it works with Fitbit's fantastic mobile app.

It tracks your basic steps, distance, active minutes and calories burned, and offers on-wrist notifications including Caller ID, texts and calendar alerts.

But be warned that you don't get a lot by way of advanced fitness features: there's no GPS, no heart monitor, no altimeter. If you can live without these, this is a sensible money-saving option, if you can find a great deal.

Read our full Fitbit Inspire review


Fitbit Ionic - Discontinued but still available

Fitbit Ionic
  • Pros
    • Fitness smartwatch
    • GPS
  • Cons
    • Older model
    • Lacks some features

While discontinued for a few years now, the Fitbit Ionic is a fully featured Fitbit smartwatch and activity tracker. It has a built-in GPS, which is great for runners or exercisers who don’t want to lug their phone around with them. Newer Fitbits, such as the Sense, Versa 3, and even the Charge 4 and 5 activity trackers also boast built-in GPS.

As well as all the usual fitness stats it features automatic multi-sports tracking, on-screen workouts, Caller ID and texts notifications on-wrist, can store up to 300 songs, with music controls and be used for contactless payments, as well as choosing from a range of special apps (Weather, Starbucks, Runkeeper, Strava, and more).

If you find a bargain, it is still a fine smartwatch, but the Versa 3 and Sense offer a lot more.

Read our full Fitbit Ionic review

Your buying guide to the best Fitbit

The benefits of getting more exercise cannot be exaggerated. Going for regular walks reduces the risk of heart attack or stroke by 31%. A study of 650,000 people found that being active for just 11 minutes a day after the age of 40 yielded 1.8 years of added life expectancy. Being active for an hour or more a day increased life expectancy by 4.2 years.

Exercise strengthens bones, boosts the immune system, lessens the risk of getting diabetes and a number of cancers (such as breast cancer), improves mood, and staves off senility. There is probably not a single organ in the body that does not benefit from exercise.

A healthy heart in our youth and middle age lowers the risk of developing dementia later in life, according to a study by Oxford University.

And it's not just physical – a 30-minute walk can prevent a build-up of stress during the day, as aerobic activities help keep levels of the stress hormone cortisol in check.

10,000 steps a day is the standard recommended goal, although this has little scientific basis. What's actually more important is how many minutes you are active in a day (experts recommend at least 150 minutes a week), and all the Fitbits measure this fitness metric, as well as steps. It's especially important if your exercise is on a bike, where steps don't really count.

The more sophisticated Active Zone Minutes measurement is nowadays available across more recent Fitbits, including the Sense, Versa 3, Charge 4, Charge 5, Inspire 2 and Luxe, but you'll also find it on older Fitbits such as the Versa and Versa 2, as the Fitbit OS updated them to support the new metric, too.

Fitbits with the 24-hour heart-rate monitor (Inspire HR, Inspire 2, Luxe, Charge 4, Charge 5, Ionic, Versa Lite, Versa 2, Versa 3 and Sense) feature Heart Rate Zones, Cardio Fitness Level, and Guided Breathing Sessions.

They also show advanced Sleep Stages data, including duration of Light, Deep and REM sleep, plus give a Sleep Score. Those without the HR (Ace 3, Ace 2, Inspire 1) offer more basic sleep tracking.

Read our full feature to learn more about all the Fitbit scores and measurements.

Another big news story is that Google finalised its purchase of Fitbit at the start of 2021, for a cool US$2.1 billion.

Fitbit features compared

For kids below the age of 13, the Ace 3 is a well-designed, basic starter tracker. It's recommended for children aged 6 and 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 standard 'Small' size options found on Fitbit's standard trackers, but we found the other Fitbits fit a child's wrist just as well.

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 "adult" models – parents just need to set up the child's account using an older birth year.

The cheapest adult Fitbit wristband is the Inspire 2, but this lacks some features of the more expensive Fitbits, such as an altimeter  – to measure floors climbed – and built-in GPS. That said, it is remarkably stuffed full of fitness functions for an entry-level device; not to mention it includes a heart-rate monitor, so can measure your Cardio Fitness scores and Active Zone Minutes, as well as insightful Sleep Stage recording. It can also be worn as a clip rather than a wristband, although the clip accessory costs an extra £19.99/US$19.95.

You can find even cheaper trackers if you consider older Fitbit devices (don't worry, we've hunted down the Best Fitbit Deals for you).

If you jog, run or exercise in any way, as well as walking, you'll be happy to learn that all the latest Fitbits (except the Ace 3) include heart-rate monitoring.

Monitoring your heart rate is useful if weight loss is one of your key goals, not to mention it also provides greater insight with regards to sleep analysis.

The Fitbit Sense and Versa 3 have built-in microphones and work with Amazon's Alexa and Google Assistant voice controls (the older Versa 2 only works with Alexa).

The Sense and Versa 3 also boast a speaker and can receive phone calls when your iPhone or Android phone is close by. Phone calls on the wrist work surprisingly well.

If you're looking for weight tracking, then check out our Fitbit Aria Air review. These scales sync with the trackers to add measurements of your weight. 

Fitbit family Q2 2021

Which Fitbit trackers have certain features?

All Fitbits have an accelerometer that measures motion patterns to determine your calories burned, distance travelled and steps taken (although the Fitbit Ace 3 does not show calories burned, as Fitbit doesn't want to add to a child's possible weight anxiety issues.) All monitor sleep quality, but those with a heart-rate monitor offer greater detail.


All Fitbits also contain a vibration motor, which allows them to vibrate when set alarms go off. 

Floors climbed

The Charge 4, Versa 2, Versa 3, Sense and Ionic boast an altimeter that measures stairs (or height) climbed. The Ace 3, Luxe, Charge 5 and Inspire 2 do not include an altimeter.


The Fitbit Sense, Versa 3Charge 4 and Charge 5 are the only models in the lineup to feature integrated GPS, meaning they don't need a constant connection to your smartphone to log GPS data. Users can see distance and pace data, and review routes and split times.

Like the Inspire 2 and Luxe, the older Inspire HR, Versa Lite and Versa 2 rely on an active connection to your smartphone to glean GPS data (also known as 'connected GPS').

Heart-rate monitoring

All current adult Fitbits monitor your heart rate on-wrist, using Fitbit's PurePulse technology to continuously and automatically track heart rate, as well a categorising it into simplified heart-rate zones (Fat Burn, Cardio and Peak). The Versa 3, Sense and Charge 5 use the updated and more accurate PurePulse 2.0 sensor.

Additionally, these heart-rate-tracking Fitbits feature Cardio Fitness Level, which provides a snapshot of your cardiovascular fitness. Based on your 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 Charge 5, Sense and Versa 3 can also notify you when your heart rate reaches high and low thresholds.

The Charge 5, Luxe, Charge 4, Versa 2, Versa 3, Sense and Ionic can also monitor the amount of oxygen in the blood (an important health indicator) with their SpO2 sensor.

Water Resistance and Swim Tracking

All Fitbits are water-resistant up to 50 metres. The Inspire HR, Luxe, Inspire 2, Charge 4, Charge 5, Versa 2, Versa 3 (not the Versa Lite edition) and Ionic will track your basic swimming metrics (laps, calories, etc) using distance to estimate strokes and laps. The Fitbit Sense has a six-axis gyroscope to more accurately track strokes and laps while swimming.

Caller ID and text messages

All Fitbits show Caller ID, when linked to a smartphone. All the wristbands except the Ace 3 also display text notifications and calendar events. When you get a WhatsApp or Messenger message, your Fitbit can notify you, and even include the message on-screen, saving you the bother of reaching for your phone. A minor but useful measure to help reduce the chances of phone theft on the street. 

Phone calls on your wrist

With their built-in speaker and microphone, the Versa 3 and Sense can receive calls when your phone is nearby. You can answer calls without getting your phone out, and the sound quality is surprisingly good.

Automatic sport recognition

The Inspire HR, Inspire 2, Luxe, Charge 4, Charge 5, Versa Lite, Versa 2, Versa 3, Sense and Ionic feature multi-sport exercise tracking. They know when you are 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.

SmartTrack automatically recognises and records workouts and captures all of the stats: how long you were active, calories burned and heart rate zones. By default, it recognises activities when you’ve been moving for more than 15 minutes. You can change this to anywhere from 10 to 90 minutes.

Reminder to Move

Thsi feature 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, of course, they won't wake you at night.

It's a great motivator to get up and move around, even if just for a stroll to get a glass of water or make a cup of tea. Studies have linked excessive sitting with being overweight and obese, type 2 diabetes, some types of cancer, and early death; bet that made you sit up...

Sleep tracking

All Fitbits can track your sleep. 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 newer Sleep Stages measurements (on Inspire 2, Luxe, Charge 4, Charge 5, Versa Lite, Versa 2, Versa 3 and Sense) 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. Sleep Score rates each night's sleep from 0 to 100.

This is one of the great benefits of a tracker with a heart monitor, and sleep is now recognised as a major health metric. Six to eight hours a day is the recommended amount of sleep you should be aiming for. Improved sleep has immediate benefits to your memory, attention, cognitive function and decision-making capacity, as well as helping to avoid type 2 diabetes and putting on weight. Sleep deprivation causes our appetite to go up and we feel less full, making weight gain more likely.

Sleep can make us happier, improve heart health, boost memory, even reduce the risk of dementia; it's vital for restoring energy levels and boosting the immune system too.

Relax – Guided Breathing

The Inspire 2, Luxe, Charge 4, Charge 5, Versa Lite, Versa 2, Versa 3 and Sense offer Relax – Guided Breathing 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. Long-term insulin resistance (caused by stress triggering the brain’s hypothalamus readying your body for action) contributes to the development of type 2 diabetes and obesity, so even light meditation has physical, as well as mental health benefits.

Female Health Tracking

All but the Ace 3 offer Female Health Tracking, which helps women understand their body by using the tracker, with the Fitbit app, to follow their cycle, record symptoms and more.

Health Metrics

All users can see seven-day trends on various health metrics, with Premium subscribers also getting a longer 90-day view. Charge 5, Charge 4, Sense, Versa family and Ionic users see breathing rate, heart-rate variability, resting heart rate, SpO2 and skin temperature. Inspire 2, Luxe, Charge 4 and Charge 3 see breathing rate, heart rate variability and resting heart rate.

Location Tracker

Fitbit has partnered with location-finding specialist Tile to add the ability to find your Fitbit if it gets lost or stolen. This functionality is, for the moment, found only in the entry-level Inspire 2.


Apps are available on the Fitbit smartwatches (Versa Lite, Versa 2, Versa 3, Sense, and Ionic), including Weather, plus extra third-party apps can be purchased via the Fitbit mobile app.

All smartwatches except the Versa Lite also boast the Fitbit Coach app, for on-screen video workouts. The Charge 4 also includes a more basic Weather app and Agenda for calendars, however, the Charge 5 does not.

The Versa 3 and Sense also feature Amazon Alexa voice assistant support, Google Assistant support and Spotify music. The Versa 2 also includes Spotify controls and Alexa. The Charge 4 (i.e. not the Charge 5) includes Spotify too. You need to be a Spotify Premium subscriber to take advantage of this feature, however.

Fitbit Pay

Fitbit Pay is available for Charge 5, Charge 4, Versa 2, Versa 3, Sense and Ionic users, but it's not on the Ace 3, Luxe or Inspire 2, or the older Inspire 1 and HR or Versa Lite. This allows for contactless payments directly from the wearable. That said, the list of compatible banks is very small right now (see the whole list for all countries).

Which Fitbit has the best display?

Fitbit Ace 3 colours

The kid-friendly Fitbit Ace 3 measures only the basic stats: Steps and Active Minutes. It can also measure a child's sleep patterns and shows Caller ID, plus offers Reminders to Move.

Fitbit Inspire 2 display screens

The Inspire 2's OLED touchscreen display (above) shows the time, steps, heart rate (Inspire HR and Inspire 2 only); calories burned, notifications (such as caller ID and texts), exercise modes, sleep data and settings.

Charge 4 screens 1

Charge 4 apps

The Charge 4's OLED touchscreen shows time, steps, heart rate, distance, calories burned, floors climbed, Active Zone Minutes, caller ID, notifications, weather, Agenda and alarm.

Fitbit Luxe screens

The Luxe and Charge 5's colour AMOLED touchscreens show the time, steps, heart rate, distance, calories burned, Active Zone Minutes, Guided Breathing, caller ID, notifications and the alarm.

The Versa 2/3's colourful touchscreen is even better for visualising fitness stats. The best and largest displays are found on the Versa 3 and Sense.

Both devices are equipped with a 1.58in panel, with a resolution of 336x336 pixels. In comparison, the display on Versa 2 is 1.39in, with a resolution of 300x300 pixels.

The dimensions of the Sense and Versa 3 pebble are 40.48mm x 40.48mm x 12.35mm, compared to Versa 2’s dimensions of 39.95mm x 39.84mm x 12.15mm.

Fitbit Sense screens

Which Fitbit has the best battery life?

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

Ace 3: up to 8 days

Inspire: up to 5 days

Inspire HR: up to 5 days

Inspire 2: up to 10 days

Luxe: up to 5 days

Charge 4: Up to 7 days (up to five hours using GPS)

Charge 5: Up to 7 days (up to five hours using GPS)

Versa Lite: 5 days +

Versa 2: 6 days +

Versa 3: 6 days +

Sense: 6 days +

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

Read our tips on how to get longer Fitbit battery life.

Which Fitbits are water-resistant?

All the Fitbit trackers are officially sanctioned as water-resistant (down to 50M), and all but the Ace 3 and Versa Lite have basic swimming tracking features (number of lengths, distance swam).

Fitbit recommends against wearing your device 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). Don't wear yours in a sauna, or even a very hot bath, as extreme heat can weaken the battery too.

Do all Fitbits use the same app?

Yes. They are all compatible with the same iPhone and Android apps.

The app displays 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.

Read our how we test wearables feature for more details.