Amazfit T-Rex vs. Fitbit Charge 4: Which should you buy?

Fitbit Charge 4 Review
Fitbit Charge 4 Review (Image credit: Joe Maring / Android Central)

Fitbit Charge 4

Fitbit Charge 4

If you want an in-depth tracking experience but you don't necessarily want a smartwatch, the Fitbit Charge 4 will do the trick. This compact fitness tracker has many essential features, including built-in GPS, heart-rate monitoring, 5 ATM water resistance, and other perks that might appeal to you.

Fitbit Charge 4

Intelligent tracker

Built-in GPS
Mobile payments
20+ exercise modes
Active Zone Minutes
Female health tracking
Shorter battery life
Small screen makes navigation tricky
More expensive but still not a smartwatch

Amazfit T-Rex

Amazfit T-Rex

While Amazfit may not be as well-known as Fitbit, it has an impressive smartwatch lineup, including the new T-Rex. This wearable is rugged as ever with tons of useful features. You'll have built-in GPS, health/activity tracking, heart-rate monitoring, and 20-day battery life. It's also quite affordable.

Amazfit T-Rex

Rugged smartwatch

Built-in GPS
Heavy-duty design
14 sport modes
Impressive 20-day battery life
Fairly priced for a smartwatch
App support is lacking
Can't change the bands
Too large for some wrists

Whether you're a beginner who's just begun tracking your daily activity or an experienced tracking enthusiast who wants every little detail, there's a wearable out there for everyone. Two options to consider are the Amazfit T-Rex and the Fitbit Charge 4. They're not far off in price, but they're geared toward two entirely different users.

One of the first questions you'll need to ask yourself is whether you want a smartwatch or a more compact activity tracker. This might be the deciding factor for some people who need more than a tracker can offer or for those who aren't particularly interested in smartwatches. You'll find that the T-Rex and the Charge 4 share many of the same perks, but there are a few distinctions that set them apart.

Larger than life

Amazfit T-Rex review

Source: Apoorva Bhardwaj / Android Central (Image credit: Source: Apoorva Bhardwaj / Android Central)

If the first thing that comes to mind when you see the Amazfit T-Rex is how large it is, you're not alone. This watch comes in a whopping 47mm case made of polymer. It's available in black, army green, and khaki. You'll get a big, bright AMOLED display with a touchscreen that's easy to navigate. Unfortunately, you don't get interchangeable straps with the T-Rex, so hopefully silicone is your preferred band material.

As far as battery life goes, you can't really beat what this watch is bringing to the table. This device has a new circuit design that was developed exclusively for the T-Rex. The advanced low power-consumption chip combined with deep power optimization results in longer battery life. With typical use, your battery will last for 20 days. If you keep your watch in basic watch mode with Bluetooth turned off, it will last up to 66 days. You get 20 hours in continuous GPS mode.

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Header Cell - Column 0 Amazfit T-RexFitbit Charge 4
Display1.3-inch AMOLED display1-inch grayscale OLED
Dimensions47.7 x 47.7 x 13.5 mm35.8 x 22.7 x 12.5 mm
SensorsBioTracker PPG, Bio-Tracking optical sensor, 3-axis accelerometer, geomagnetic sensor, ambient light3-axis accelerometer, altimeter, optical heart rate monitor, NFC
Battery life20 days7 days
Water resistance5 ATM5 ATM
Onboard GPS✔️✔️
Mobile payments✔️
Interchangeable bands✔️
Military-grade durability✔️

No matter what type of activities you enjoy, you'll be able to track it with the Amazfit T-Rex. You have 14 sport modes, including walking, trail running, indoor and outdoor cycling, pool and open water swimming, hiking, climbing, and more. Additionally, you'll have built-in GPS for tracking your route, heart-rate monitoring, sleep tracking, and more.

Many users will love the fact that the Amazfit T-Rex has passed 12 military-grade certifications.

Many users will love the fact that the Amazfit T-Rex has passed 12 military-grade certifications. It can withstand conditions as hot as 150 degrees or as cold as -104 degrees Fahrenheit and it can last for 240 hours in damp heat. It's also waterproof up to 50 meters, so you can take it for a swim or in the shower without a problem. Needless to say, you'll be unstoppable with this watch on your wrist.

Compact but capable

Whether you're a beginner who's not quite ready for a full-blown smartwatch or you happen to be a loyal Fitbit user, the Charge 4 might be the better option for some folks. As you might've guessed, the design is much more compact and lightweight. You'll have the option to change the bands on this device, which is important to some users. Don't expect a fancy display or a ton of functionality. You'll need to do a lot of your navigating in the mobile app. With a compact design, you end up settling for a smaller screen.

It might be small, but you still get a full week of battery life with the Fitbit Charge 4.

It might be small, but you still get a full week of battery life with the Fitbit Charge 4. It will last for 5 hours in continuous GPS mode. This tracker also comes with heart-rate tracking, advanced sleep monitoring, and female health tracking. The new Active Zone Minutes feature uses the heart rate sensor to ensure you have an optimal workout when you exercise. You'll earn credit when you get your heart pumping and it gives you daily and weekly goals to work toward.

This device also has 5 ATM water resistance, so you don't have to worry about getting it wet. You'll enjoy 20+ goal-based exercise modes, including running, biking, swimming, yoga, and more. It also has automatic workout recognition for some activities in case you forget to start it manually. You'll enjoy mobile payments with Fitbit Pay as well as Spotify Connect & Control that lets you control your Spotify music from your wrist.

Bottom line

While each of these devices has its selling points, it most likely will come down to what type of tracking experience you want. If you're looking to do most of your navigating right from your wrist, then you'll want a large display that's easy to navigate. In that case, the Amazfit T-Rex is the better pick. It's also highly durable, so you don't have to worry about wearing it down with your active lifestyle. As we mentioned, the bands aren't interchangeable and the app support needs work. Other than that, this is a stellar smartwatch at a low price.

Alternatively, do you want to be tracking your workouts in a few quick motions and then have all the data readily available on your phone's corresponding app? The Fitbit Charge 4 is ideal. It's also lightweight, compact, and unassuming. If you're not trying to make a statement with your wearable, this is a very subtle accessory that won't stand out. Not to mention that the Fitbit ecosystem is superior to Amazfit's.

If you're set on having a tracker rather than the best Android smartwatch and don't mind paying more, you'll likely be a fan of the Fitbit Charge 4.

Overall, the Fitbit Charge 4 is the best fitness tracker for most people. It has a superior suite of apps, it fits the most wrists, and is the best for people who do general fitness and exercising. If you do a lot of outdoor sports or plan on going backpacking, the T-Rex is no doubt the best fit.

Courtney Lynch

Courtney Lynch is a freelance writer at Android Central. She's obsessed with all things health, fitness, and music. At any given time, she can be found checking out the latest and greatest gadgets while simultaneously petting her dog and sipping iced coffee.