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Fitbit Charge 4 vs Apple Watch 4 (2021): Do You Need A Fitness Tracker Or A Smartwatch?

Apple and Fitbit continue to blur the lines between fitness trackers and smartwatches, and now most shoppers assume they mean the same thing. However, one becomes the clear choice over the other depending on what you want a wearable for. We compare the new Fitbit Charge 4 and the discontinued Apple Watch Series 4 to showcase the important differences between these two categories.

Fitbit Charge 4 vs Apple Watch 4 Fitness Smartwatch Comparison Chart

ModelFitbit Charge 4Apple Watch Series 4
Fitbit Charge 4Apple Watch Series 4 - Silver Aluminum
PriceCheck PriceCheck Price
Screen Size1.36″1.78″
Dimensions1.4″ x 0.9″ x 0.5″1.73″ x 1.5″ x 0.42″
Weight0.7 oz1.06 oz
Call & Text AlertsYesYes
Water ResistanceUp to 50 metersUp to 50 meters
Heart Rate MonitorYesYes
ECG MonitorNoYes
Calorie Burn TrackerYesYes
Sleep TrackingYesNo
Swim TrackingYesYes
Female Health TrackingYesYes
CompatibilityiOS, Android, WindowsiOS
Battery Life7 days18 hours


The Apple Watch 4 has a sleek design and premium build quality compared to the Fitbit Charge 4.

Fitbit Charge 4 vs Apple Watch 4 Fitness Smartwatch Design
It’s easy to see how different the Fitbit Charge 4 (left) and Apple Watch Series 4 (right) looks.

One look at the Fitbit Charge 4 and Apple Watch 4 side by side shows how different they are, and it’s not just in looks, either. The vertical and narrow display of the Charge 4 allows it to meld smoothly with its band’s width, so it looks and feels like a singular strip on your wrist. It’s lightweight and unobtrusive and its straight edges speak of practicality and focus on function.

In comparison, everything about the Apple Watch Series 4 looks sleek and modern. It’s all rounded curves so it appears soft and pretty. The case comes in aluminum or stainless steel, but either way, it’ll add a bit of weight on your wrist. It looks more like a traditional watch, though, which is a plus for those used to wearing them.

Turning on both wearables emphasize even more distinctive qualities. The Charge 4 has a grayscale LED screen that’s backlit for daylight visibility. Meanwhile, the Apple Watch 4 uses an OLED Retina display that’s in full color and in high resolution. Apple essentially took a mini iPhone screen and added a strap to it. Saying it looks good would be understating how vibrant and bright it is, especially once you start discovering its apps.

Overall, it’ll feel and look obvious that the Apple Watch Series 4 is the more premium device while the Fitbit Charge 4 cuts on flashy elements for a more streamlined form.

Activity Tracking

The Fitbit Charge 4 offers sleep tracking while the Apple Watch 4 has an ECG app.

Fitbit Charge 4 vs Apple Watch 4 Fitness Smartwatch Activity Tracking
Aside from these two features, the Charge 4 and Apple Watch 4 share nearly the same activity tracking functionalities.

It’s interesting to see the evolution of Fitbit’s Charge series and Apple’s smartwatches. The former is a fitness tracker adding smartwatch features while the latter is a smartwatch improving its fitness tracking capabilities. By their fourth versions, the Charge 4 and Apple Watch 4 are almost neck and neck in terms of how well they can track your exercise metrics.

Both wearables are able to automatically detect and record common exercises such as running and cycling, and they support numerous workouts including swimming and yoga. Using their heart rate monitors, pedometers and accelerometers, they’re able to measure calorie burn and show your progress over time. You can view a history of workouts and metrics to check your personal growth as well as to compare with friends.

Their biggest difference here is that the Charge 4 lets you track sleep quality. It has a Sleep Score feature which is able to differentiate between how much light, deep and REM sleep you’re getting. You can get recommendations on how to get more restful sleep on Fitbit Premium, which you get to try out free for 3 months. Meanwhile, Apple chose to enhance its heart rate sensor with an ECG app, which detects potential problems based on heart beat rhythm.

Fans of the Charge series will be glad to know that the Charge 4 finally has built-in GPS. You can now go outdoors and track exercises without relying on your phone’s GPS, which you can also do with the Apple Watch 4. They’re also waterproof up to 50 meters, so feel free to include laps in the pool in your workout regimen.

Smart Features

The Apple Watch 4 has access to a larger app library and can get better connectivity than the Charge 4.

Fitbit Charge 4 vs Apple Watch 4 Fitness Smartwatch Smart Features
Those who truly want an independent wearable can check out the GPS+Cellular versions of the Apple Watch 4.

As mentioned, the Apple Watch Series 4 is a smartwatch first and fitness tracker second, it has the advantage over the Fitbit Charge 4 when you’re looking at smart features. Connectivity-wise, it has Bluetooth, Wi-Fi, and NFC, so you can download apps on it directly and use it for contactless payments. Moreover, it has a GPS+Cellular variant, which lets you make phone calls, send texts, stream music, etc., even without bringing your iPhone.

Perhaps more importantly, the WatchOS library of apps is more extensive and feature-rich. With the greater processing capabilities of the Apple Watch, developers are able to make a wide selection of apps that take advantage of its display and enhanced controls. It also has a mic and speaker so you can speak with Siri. In short, you’ll be able to do a lot more on the Apple Watch 4 than simply track exercises.

In contrast, the Fitbit Charge 4 only has Bluetooth and NFC, the latter of which is newly added to the standard edition of the Charge. It doesn’t have Wi-Fi, much less cellular, connectivity, and the apps you can install on it are more limited in scope as well as visuals. Fitbit added Spotify control as well as Pandora and Deezer access to the Charge 4, but it still requires your phone.

There are also some nice extra functionalities on the Apple Watch 4 such as Emergency SOS and fall detection. It can sense if you’ve taken a fall and will automatically bring up a button that contacts emergency services or your designated contact person.

Battery Life and Other Features

The Fitbit Charge 4 has a much higher battery capacity than the Apple Watch 4.

Fitbit Charge 4 vs Apple Watch 4 Fitness Smartwatch Battery Life
Track daily runs and sleep quality for a week without taking off your Fitbit Charge 4.

Maybe the best reason to choose a Fitbit tracker over an Apple smartwatch is battery life. All of the fancy features and eye candy that the Apple Watch 4 provides requires a lot more power, so even when fully charged you can only get up to 18 hours of use out of it. You can perhaps get a day or two of continuous use if you don’t play around with other apps and aren’t turning GPS on, but getting low battery warnings will be common.

To compare, the Fitbit Charge 4‘s battery capacity is measured in days, not hours. A full charge can last up to 7 days, so you can keep wearing it day and night to record all of your health and fitness metrics. Using GPS will drain it very quickly though, so note that you’ll need to plug it in after outdoor exercises where you use it.

Finally, we’d add that controlling the Apple Watch 4 feels more intuitive and smooth, thanks to its Digital Crown. This tiny knob lets you navigate the device without your finger blocking the touchscreen. You get a tiny haptic feedback that makes scrolling and selecting precise and satisfying.


The Fitbit Charge 4 is recommended for serious fitness enthusiasts while the Apple Watch 4 is the more versatile wearable.

Fitbit Charge 4

Fitbit Charge 4

Apple Watch Series 4

Apple Watch Series 4 - Silver Aluminum

As the heavily fitness-focused device, the Fitbit Charge 4 is definitely targeted towards users who want to get serious about improving their health through consistent exercise. With the highly acclaimed Fitbit app, you can get all of the data you need to discover your day to day progress and find areas of improvement. Moreover, with the included Fitbit Premium trial, you can take advantage of guided workouts, participate in challenges, and look for insights to help fuel your fitness journey.

Those who want to be able to do more with their smartwatch should definitely go for the Apple Watch Series 4. Not only does it let you track workouts, you can store and stream music on it, access voice assistants, and use a plethora of apps, which all look great on its Retina display. You’ll have to really consider whether spending at least twice the cost of the Charge 4 is worth it for you though. But if it is, you’ll be wearing a premium gadget that does so much more than simply tell the time.

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Derick Bondoc

Managing Editor at Compare Before Buying. Writer and researcher passionate about gadgets, gaming and snacks.