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Review: Fitbit Charge 4, a great fitness band just got even better

Fitbit Charge 4




Ease of use


Use of information





  • Built in GPS works well
  • Like the Charge 3, but better value.
  • Useful training tools
  • NFC as standard feature
  • Decent battery life


  • Bland design
  • Small, monochrome display
  • Few apps
  • Still doesn't integrate with Apple Health or Google Fit

Fitbit is the first brand most people think of when someone mentions a fitness tracker. This is for a good reason. The San Francisco-based outfit has been one of the leaders in this field for a number of years now. The company is known for churning out devices for the average person who does the occasional run, swim or cycle here and there.

Essential reading: Top fitness trackers and health gadgets

The big news, of course, is the Google acquisition. It is still pending regulatory approval, but assuming all goes well the search giant will take Fitbit under its belt by the end of this year. If the transaction doesn’t go through Fitbit will get a cool $250 million. In any case, a nice little earner for the company.

In the meantime it is business as usual for the wearable brand. Its latest fitness tracker to see the light of day is Charge 4, an updated version of Fitbit’s best selling activity tracker. It comes with a number of smaller upgrades including an all-important one – built-in GPS. You won’t find many fitness bands with built-in GPS.

Fitbit Charge 3 has been our recommended activity band since its launch over two years ago. Is Charge 4 the new go-to device? Read on to find out.



Charge 4 is very similar to its predecessor. My hope was the design would receive a revamp, but the new tracker looks exactly like the old one. The display is the same with the Fitbit logo underneath, the one physical button is just an indent. Bland is the word that comes to mind. We’ll just have to wait for Charge 5 for bigger changes. I really was hoping that Fitbit would modernise the look a bit.

In terms of actual specs, the core unit of Charge 4 is slightly thicker than its predecessor. Not that it’s going to make much of a difference. Hardly anyone will be able to tell that it’s 12.5mm instead of 11.8mm.

As before, the screen is fully responsive to touch and supports greyscale colours. The backlight has been improved so that adjusts better to changes in lighting conditions. Indoor visibility is great, outdoor visibility will do the job but it’s still nothing to brag about.

You can use the inductive button to wake up the tracker and go back to the home page. A tactile vibration will let you know that it is working. This type of button was introduced two years ago to improve water-resistance to 5 ATM, which is enough for worry-free swimming.

Review: Fitbit Charge 4, a great fitness band just got even better

The other way to wake up the display is to flick your wrist. This option sometimes works, sometimes it takes a couple of tries.

Navigation is done by swiping on the display. Down will take you to notifications, up through your fitness stats, left and right through other apps and functionality. If you’ve used a Fitbit device before, you’ll feel right at home. No learning curve there.

You can customise the main screen with different clock-faces. Selecting a clock face in the app will automatically sync it with the tracker.

In the box Charge 4 comes with a large and small strap which you can use depending on your wrist-size. The straps are also backward compatible so if you have a favourite Charge 3 band, its not a problem swapping it over.

The device comes in two iterations. The standard variant which is available in Black, Rosewood and Storm Blue/Black, and the Special Edition (SE). The latter one comes with a fancier granite reflective/black woven band, plus a classic black band. The models do not differ technically.

Packed under the hood is Fitbit’s typical gamut of sensors. This includes a 3-axis accelerometer, optical heart rate monitor, altimeter and vibration motor. Now you also get NFC as default. Previously, only the special edition of Charge 3 has NFC for payments on-the-go through Fitbit Pay.

As mentioned, the other big change is the addition of built-in GPS. So far, the only other Fitbit tracker with this is Ionic. The functionality allows for satellite tracking of movements, without the need for a smartphone – something runners and cyclists, in particular, will appreciate. The number of exercise modes has been expanded to over 20, and built-in GPS will certainly come handy with this.

The relative SpO2 sensor is also there, and Fitbit has finally put it to good use earlier this year. It charts your blood oxygen oscillations during the night and eventually it might be used to monitor for conditions such as sleep apnea, allergies and asthma.

Fitbit devices are known for their decent battery life and Charge 4 is no different. Just like its predecessor you can get about a week on a single charge. In my testing I found the tracker had no problems reaching this figure.

Switch GPS on and this falls to around 5 hours. That might be enough for you to run a marathon, but for some it might not be. Nevertheless it’s a decent amount of time for a fitness band with built-in GPS.

You will soon have the option to use Connected GPS, as well. Fitbit says it will come as a future software update. This taps into your smartphone for the satellite signal so does not eat up as much battery life. It will be a useful option to have when it lands.

To refuel – simply plug the proprietary charging cable into a USB port, connect it to your tracker and make sure its gold pins are aligned. It takes about an hour or two get it from zero to full capacity.


There is no point in delving too much into the standard fitness tracking features. This is what Fitbit is known for. Everything is there including data on steps, calories, distance, floors and activity.

The sleep statistics are worth a special mention. Fitbit software has benefited from a number of upgrades over the years and now on most of its trackers you get Light, Deep and REM sleep info. The values are calculated by combining accelerometer data, heart rate variability (the time between beats), and Fitbit’s proprietary algorithms. Opting for a Premium subscription ensures you get even richer data.

Review: Fitbit Charge 4, a great fitness band just got even better
Sleep insights in Fitbit Premium

There are Sleep Insights that dish out personalised guidance and you can set bedtime and wake-up targets; reminders to stay on schedule, and a sleep schedule history to chart your progress. And let’s not forget the silent alarm which does a decent job at waking you up by vibrating without waking your partner. For important meetings, I would hesitate to rely just on the vibrating alarm, though.

Something that can be found on Charge 4 is a Sleep Mode. This turns off notifications and blanks the screen so you’re not woken up by any rogue text alerts.

Even more interesting is the pulse oxygen tracking. This works overnight to let you know how well oxygen is delivered to parts of your body. You don’t get the actual values but you do get a nice chart which outlines fluctuations. The goal is to keep these low. Anything high might be an indicator of a condition such as sleep apnea. Fitbit will not diagnose these but will instead let you draw your own conclusions from the chart.

Everything that I have listed so far can also be found on Charge 3. So let’s focus on what is different.

As mentioned, the most important change is the inclusion of a GPS chip in Charge 4. Built-in GPS means you can go running or cycling outdoors, leave your phone behind and still get detailed statistics and a map of your route. This is going to make a huge difference to some, but others won’t even notice it. If you use GPS often to track your outdoor exercise, you will appreciate the addition.

In terms of exercises, the fitness band allows you to choose from a range of modes. This includes bike, swim, run, weights, yoga and more. Each comes with its own set of metrics, screens and more. There’s also a new goal-based exercise mode. This lets you set a specific calorie, time or distance goal ahead of your workout and then track it during your exercise.

The device has automatic exercise recognition but you can also start a workout manually. This, however, involves multiple taps. As a previous user of Charge 3, I have trained myself to always start workouts manually. Better safe than sorry. Also for activities that use built-in GPS, you do need to start a workout manually in order for the sensor to kick in.

Because the display is still small you can’t really fit that much information on it. Three bits of data is about it, and its also not easy to read when you’re running or cycling. Swiping left and right changes the metrics. Post workout you can see a short a summary of how you’ve done right on the screen. More info can be found in the smartphone app.

Review: Fitbit Charge 4, a great fitness band just got even better

I’ve gone on a number of runs and found that the GPS works pretty well. It does not take too long to obtain a signal (30-45 seconds at my home in central London), the signal does not drop, and the distance readings are consistent and accurate.

There are also a number of new software-based features which tap into these readings. The first is the ability to show training intensity on a map after a workout. This can either be in the form of pace or heart rate zones shaded throughout your route. In essence, it serves a heat map.

Then there is something Fitbit calls Active Zones. This measures the intensity of your activity by rewarding you points for various heart rate zones. The overall goal is to accumulate 150 active minutes each week (or 75 minutes of vigorous activity), as per recommendations from the World Health Organization.

Whats more Charge 4 will alert you with a buzz when switching from one zone to another -one buzz for fat burn, two for cardio, and three for peak. Useful info as it allows you to take action during your workout without looking at your fitness band. But it means that it might vibrate often depending on how often you switch between zones.

As before, you also get an alert when you hit your peak heart rate. All these upgrades make Charge 4 a more decent alternative to fully-fledged running watches.

Review: Fitbit Charge 4, a great fitness band just got even better

In terms of non-fitness features, there’s the above mentioned NFC which comes built into all Charge 4s. Again, this is something that will make a difference to those who use Fitbit Pay but those that don’t won’t even notice it. Fitbit Pay is currently supported by more than 100 banks in a multitude of countries. Everything is managed from the Wallet section of the Fitbit app. This is where you can add/remove payment cards, set a default card, edit payment methods and review recent purchases.

Amongst new features is also the ability to operate Spotify. This is the first time we’ve seen the functionality on a Fitbit fitness band, although its smartwatches have it. It allows you to control music playing in the Spotify app on your smartphone. So it doesn’t support offline music playback. In essence it’s just a means of liking and choosing songs, playlists and podcasts on your paired phone or other device which is connected to the internet. No built-in storage for music. Perhaps Charge 5 will fix that.

The other smart features are the same as before. This includes call, calendar, text and smartphone app notifications. There are also apps such as Alarms, Timer, Weather and more.


The verdict

Smartwatches might be all the rage at the moment but there’s still a market for people who prefer fitness bands. Not all of us want something bulky on our wrist.

If you’re one of these, the Fitbit Charge 4 is one of your best options right now. Until something better comes along, the tracker takes the mantle from Charge 3 as our recommended fitness band.

The all-important difference is the built-in GPS. It is something avid runners or cyclists will appreciate, as it means they can leave their smartphone behind when exercising. The functionality helps make Charge 4 a viable alternative to fully fledged sports watches. Its only real competition is the Garmin Vivosport.

Fitbit Charge 4 vs Charge 3: what’s the difference?

Fitbit Charge 4
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Fitbit Ionic or Garmin Vivoactive 3: which to get?

Having said that, if you don’t use GPS very much Charge 3 still presents as an intriguing option. Particularly now that its price is coming down. You will miss out on a few other extras that can be found on Charge 4. This includes NFC for contactless payments (unless you purchase the SE edition), the ability to operate Spotify and some software-based activity tracking improvements.

All things considered, Charge 4 presents itself as a decent package that doesn’t break the bank. I had hoped Fitbit would modernise the design but the tracker is still bland in the looks department. Nevertheless, the latest iteration is a much better device for serious athletes. It provides just enough data to be useful without overloading with information.

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Marko Maslakovic

Marko founded Gadgets & Wearables in 2014, having worked for more than 15 years in the City of London’s financial district. Since then, he has led the company’s charge to become a leading information source on health and fitness gadgets and wearables.

One thought on “Review: Fitbit Charge 4, a great fitness band just got even better

  • My main and only requirement is to buy the most accurate sleep tracker available. I’ve spent money on various wearables without finding a reliable one.


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