Fitbit’s latest activity tracker, the Charge 4, looks set to become 2020’s top fitness wristband, with a bunch of new features and functions that rival even Fitbit’s pricier fitness smartwatches.
And, sometime this year, it will become a Google device after the search giant’s purchase of Fitbit is passed by legislators.
Fitbit’s best-selling fitness tracker in 2019 was the Charge 3, and for good reason – it was also Tech Advisor’s best all-round Fitbit in our Best Fitbit roundup based on features and budget. The Charge 4 now easily holds this crown.
The Charge 4 has everything the Charge 3 had, and a lot more on top (see a fuller comparison below). Even owners of the excellent Fitbit Versa 2 smartwatch will look enviously at some of the new features.
Best of all, there’s a great new fitness metric to get excited about. Long-time Fitbit owners will have 10,000 steps well covered (even that buzz has lost its fizz), and this has become a less interesting challenge.
For a change, I tried Floors Climbed as my main goal for a while, which was great to get the heart pumping, and the all-new feature (debuting on the Charge 4) builds on this.
Active Zone Minutes (AZM) is a personalised fitness challenge that counts all your activities that push your heart rate up – be that running, weights, cycling or dancing. The harder you push yourself (into Cardio and Peak zones), the more credit Fitbit gives you. Read on for more details.
On top of AZM, the Charge 4 comes with built-in GPS and Spotify Connect & Control – both not available on the older Charge 3.
The Fitbit Charge 4 is primarily a fitness tracker, but comes with other health-focused features and handy on-screen notifications such as texts and caller ID.
In this review we’ll look at all the features (fitness, wellbeing, notifications, apps, etc), and compare it to the other Fitbits, especially the previous Charge 3 and the recent Inspire HR.
Fitbit Charge 4 price
The recommended retail price for the Fitbit Charge 4 is £129.99 / US$149.95 / €149.95. You won’t find many bargains at launch time but keep a lookout for the best Fitbit deals.
There is also a Special Edition Charge 4, selling for £149.99 / $169.95 / €169.95. This offers a couple of exclusive wristbands – including a rather natty woven one – but is no different in terms of features and functions. (In the past, Special Edition models had an extra feature or two, but this is just a unique look for that extra few pounds or dollars.)
For all Fitbit models, read our full list of the best Fitbit for you – based on your needs and budget.
Fitbit Charge 4 features
Starting with the basics, the Charge 4 tracks steps, distance, calories burned, hourly activity, floors climbed, heart rate, swim-tracking, and sleep.
Packed into the small tracker are a 3-axis accelerometer, optical heart rate monitor, GPS, Vibration motor, NFC chip for Fitbit Pay, Altimeter, and Bluetooth LE (BLE).
Heart-rate monitoring is great for tracking calorie burn and getting real-time guidance to optimise your workouts. It is also used to give you advanced tracking of your sleep.
In addition, the Charge 4 features most of Fitbit’s more advanced functions, including: Cardio Fitness Level (via three different heart-rate zones); Guided Breathing; Reminders to Move; Auto Exercise Recognition; Exercise modes such as run, bike, swim, treadmill, weights, yoga, and circuit training; Female Health Tracking; Sleep Score; alarms, timers, calendar and weather app; and can display Notifications such as Caller ID, texts, Calendar, WhatsApp, and more.
At last! GPS built-in
New to the Charge 4 (and a first on Fitbit’s non-smartwatch trackers) is a built-in GPS.
Having a GPS built into a tracker delivers deeper fitness and health analysis to improve your runs and cycle workouts, such as pace, rest times, speed, and more.
Most Fitbit tracker wristbands allow you to connect to your phone’s GPS, but this way doesn’t always clock the correct distance travelled as it calculates it uses stride length to estimate this.
With GPS built-in, you get accurate data, and you can go running, riding or hiking and leave your phone at home and still log your real-time pace and distance.
There are six GPS-enabled exercise modes: Run, Bike, Swim, Treadmill, Outdoor Workout, and Walk. An Outdoor Workout, such a hike, is regarded as more strenuous than a walk, and burns more calories.
A workout intensity map shows your GPS-monitored route, distance, achieved heart-rate zones, and pace by kilometre or mile. You can tap the map to see more detailed stats about your workout.
GPS is set as “On” as a default when you select an Exercise mode, but to save battery life you can turn it off. Like most high-end Fitbits, the Charge 4 can use Run Detect and Auto Stop to work out that you are going for a run, but won’t automatically fire up the GPS.
Owners of the Versa 2 will be jealous, as even Fitbit’s most recent smartwatch lacks a built-in GPS. Expect the Versa 3 to come with one later in the year.
Active Zone Minutes
New to Fitbit is Active Zone Minutes (AZM), which debuts on the Charge 4.
This new metric is personalised based on your resting heart rate and age. It tracks any activity that raises your heart rate – from a brisk walk, to running, indoor biking and yoga. It measures the time you spend in each heart rate zone.
Fitbit measures three active heart-rate zones: starting with Fat Burn, through Cardio to Peak.
Fitbit uses your “heart-rate reserve”, which is the difference between your maximum heart rate and your resting heart rate. It’s an indication of your overall cardiovascular fitness. Your resting heart rate can be lowered by increasing your fitness level.
You can set your own goal, but the default is a weekly goal of 150 minutes (as recommended by the World Health Organization and the NHS).
AZM isn’t really that new. Fitbit has measured your Active Minutes for a long time. Now, however, it has gamified the metric a little, and uses the heart-rate zones in a more upfront manner. You earn one credit for each minute of moderate activity in the Fat Burn zone, and two for more vigorous activity in Cardio and Peak zones.
Each time you change heart-rate zones the tracker gives you real-time alerts on your wrist, so you can push harder (or scale back) to make your workouts more efficient.
You can get a detailed summary of your movement through the heart rate zones in the Fitbit mobile app.
Active Zone Minutes will later roll out to all Fitbit smartwatches, but, at launch, is just for the Charge 4 for now, and we rate it as a new motivating metric to set your goals around.
Keep on moving
From the clock face you swipe up to see the Today app, which shows your daily stats, including Reminders To Move, which will prompt you to get up out of your chair and start moving for at least 250 steps per hour of the day.
Reminders to Move is a great way to make sure you don’t stay sitting for too long – and we spend over half our day sat down. It’s not just about getting your steps up and burning a few more calories. Sedentary people have up to a 49% greater risk of early death. To take two examples, sedentary behaviour leads to a 112% increase in your risk of getting Type 2 diabetes, and 147% increase in risk of heart disease.
Fitbit Charge 4 sleep monitor and Guided Breathing
Sleep is a key health and wellbeing indicator, and the Charge 4 gives you a Sleep Score based on detailed Time Asleep, Deep and REM sleep stages, and Restoration (the time that your sleeping heart rate is below your average waking heart rate). Only Fitbit Premium subscribers get to see the Restoration data, which is a shame, but you can live without it as you get to see your overall Sleep Score regardless.
The tracker is light and comfortable to wear, and it won’t stop you sleeping, unless you set a silent alarm to vibrate, of course.
The tracker doesn’t yet feature Smart Wake, though it is “coming soon”. Smart Wake is a Fitbit smartwatch feature that buzzes you during light sleep within the 30 minutes of your set alarm to wake you in a calmer way than the sudden alarm at 6am or whenever.
When not sleeping, you can still relax by using the calming Guided Breathing Sessions based on your heart rate.
Another health metric you’ll find under the Sleep section of the app is Estimated Oxygen Variation, which uses an Sp02 sensor to graph an estimation of the oxygen-level variability in your bloodstream – which can show potentially risky variations in your breathing during sleep.
Fitbit Charge 4 apps and non-health functions
One of the smartest non-fitness or health-related features is Notifications. The Charge 4 will gently buzz you when you get a call on your phone (and show Caller ID), text messages, and smartphone apps such as WhatsApp. Android users can even send Quick Replies straight from the tracker.
These can be turned on and off to your liking on the tracker or in the mobile app.
You also get a three-day Weather forecast app, set to your location. Plus a new app, Agenda, which you can sync with a calendar.
Now all models of the Charge 4 feature contactless Fitbit Pay – which works just like Apple or Google Pay. On the Charge 3, only the Special Edition had Pay.
The tracker comes with 24 different clock faces to choose from, although these aren’t as dynamic and colourful as the ones you can get for the Fitbit Versa and Ionic smartwatches.
Despite backlighting, the display can be difficult to read in bright sunlight, and almost impossible in sunglasses. Again, only the smartwatches will fix this problem.
Fitbit Charge 4 design and straps
The Charge 4 looks very much like the Charge 3. Made of aluminium, it’s incredibly lightweight and swim-proof (up to 50m).
It has an inductive rather than a physical button on the left edge, which aids its water resistance.
To navigate to its many features, you tap, scroll and swipe the backlit 100-x-160-pixel OLED touchscreen.
The tracker itself comes with both Small and Large sizes of detachable wristband – a swim-proof Classic band made from elastomer in one of three colours, and the black Special Edition, which comes with a Granite Reflective Woven band plus an extra Black Classic band.
The tracker itself can be swapped between different wristbands. For the Charge 4 these include: Sports (£19.99 / $29.95 / €29.95), Horween Leather (£59.99 / $49.95 / €69.95), Woven (£24.99 / $34.95 / €39.95), and Classic (£19.99 / $29.95 / €29.95).
The Classic and Sports bands are sweat and swim-proof, while the Woven and Leather bands are not intended for high-intensity workouts – so you’ll need to swap to one of the other bands when swimming or working up a sweat.
The accessory bands are available in either Small (fits wrists 5.5-7.1in or 140-180mm) or Large sizes (7.1-8.7in, 180-220mm). Fitbit has a sizing tool that you can print out to see which size fits you.
To make it easier, here is the full range of available Charge 4 bands in all their glory. They fit both the new Charge 4 and the older Charge 3.
Charge 4 battery life
The tracker boasts one of Fitbit’s longest-ever battery life spans, of up to seven days. Compare that to the Apple Watch, which has an 18-hour battery life and usually requires an overnight charge.
Of course, battery life varies with use and other factors. Fitbit claims that it will last up to 5 hours with continuous GPS use. Apple says that its smartwatch lasts an hour longer with GPS in use.
The tracker comes with its own charging cable, which strangely seems to be incompatible with the Charge 3 and vice versa, but Fitbit has a long history of creating new chargers for each and every model of tracker and smartwatch.
Battery life is important as no Fitbit user wants to wake up before a long walk or run to find their tracker needs charging – a feat that’s difficult to achieve while on the move, even with a power bank.
And talking of waking up, that long battery life allows Fitbit to properly monitor the quality of your sleep, which the Apple Watch can’t do if it’s charging overnight.
Now, we’ll look at whether the Charge 4 makes a worthwhile upgrade for Charge 3 owners, and if there’s a cheaper tracker or better smartwatch you might consider.
Fitbit Charge 2 vs Charge 3 vs Charge 4
The two trackers are nearly identical. When you put the two next to each other, it’s in my opinion impossible to see any difference. According to Fitbit, the C3 was 1.41in height and the C4 is 14in. The C3 was 0.89in wide, the C4 is 0.9in, but this may just be the company rounding to the nearest decimal. The wristbands are compatible between models, so let’s say they are the same.
In a first for Fitbit, even the charging cables are the same!
The inside differences are the built-in GPS and Spotify controls, plus the new Active Zone Minutes measurements.
Should you upgrade your Charge 3 to the new model 4?
If you don’t need the GPS (for super-accurate distance measurements of your run/walk/cycle, and the ability to leave your phone at home) and are happy to just connect your Charge 3 to your phone’s GPS, and you can live without Spotify controls on your wrist, then we wouldn’t recommend upgrading to the new tracker as the other features are very close.
If the Active Zone Minutes feature appeals, then maybe you can move to the Charge 4 and give your old tracker to a friend or family member.
If, however, you own a Charge or Charge 2, the new model is a must. The 3 and 4 have displays that are 40% larger than that of the Charge 2, and they are 20% lighter due to their aluminium rather than stainless steel tracker body.
The C2 has a physical button rather than the less-obvious inductive button, which means it’s not swim-proof like the C3 and C4.
And you might find some great Fitbit deals on the Charge 3, which we’ve seen as low as £90 or $117 online.
Fitbit Charge 4 vs Inspire HR
While the Charge 4 ably takes over from the Charge 3 as our recommended all-round Fitbit, we still believe that the company’s Fitbit Inspire HR is the best deal tracker for most people.
At £89 / $89 / €89 the Inspire HR is nearly a third cheaper than the Charge 4, although lookout for the best Fitbit deals.
The Inspire HR features all the basics: steps, calories burned, active 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 Charge 4’s built-in GPS but can connect to your phone’s GPS – just s you can rely on your phone for Spotify and music as usual.
It also misses out on the new, advanced-level Active Zone Minutes, but this shouldn’t deter the average fitness tracker user.
The Charge 4 offers more, but consider whether these neat features warrant the extra cost, although we do prefer the overall look of the Charge 4, too.
Fitbit Charge 4 vs Versa 2
The next logical step up from the Charge 4 is the Fitbit Versa 2 smartwatch. This boasts a colour touchscreen with on-screen workouts, large choice of apps, Alexa voice assistant, and music storage but lacks the Charge 4’s built-in GPS, and, for a short while, Active Zone Minutes.
We love the Versa’s much-easier to read colour touchscreen, but that missing built-in GPS will hurts Versa 2 owners. So really this choice comes down to the screen vs GPS. You can, of course, link the Versa 2 to your phone’s GPS.
Wearing a Fitbit as a watch might swing the larger colour screen for you, as it will if you want the onscreen workouts via Fitbit Coach or Premium.
But the Charge 4 has just about all the fitness and health features else the Versa 2 offers, and is slim enough to wear with a different watch anyway.
We were big fans of the Charge 3, so it’s no surprise that we love the Fitbit Charge 4 just that little bit more, with its great new features, especially the personalised Active Zone Minutes, which adds a new motivational fitness metric to aim for. It’s our new favourite all-round Fitbit tracker, and it bests even the Versa 2 smartwatch with its built-in GPS.
If you want on-screen workouts, a colour screen and access to more apps, you’ll want to consider one of the Fitbit smartwatches. But the Charge 4 has all the functions you need to motivate yourself to become fitter and generally healthier.
Fitbit Charge 4: Specs
Tracks steps, distance, calories burned, hourly activity, floors climbed, heart rate, swim tacking, and sleep