Huami Amazfit T-Rex review: the affordable military smartwatch

Amazfit T-Rex release date and price

The Amazfit T-Rex comes with a recommended retail price of $139.99. For the outdoor market this is targeting, that is considered very affordable. Given the military certifications for durability, Huami is continuing to undercut the competition on price.

The durable smartwatch is available in Camo Green, Army Green, Khaki, Rock Black, Gun Gray. I tested the Rock Black version.

Big, bold, and unashamedly robust

The Amazfit T-Rex has a rugged and bold shape. The body itself is made of a high-durability polymer material. There are also large metal buttons for ease of control when outdoors and a raised bezel and protective bumpers. The polymer material doesn't feel high-end or luxurious in any way, but that's not the point here. The T-Rex smartwatch, unlike its prehistoric namesake, is a lot lighter than it looks though. Without the strap, the wearable device comes in at 39 grams. It's a pleasant surprise when you consider how big and bulky it is.

The sturdy watch is held onto your wrist with sweat-absorbent and silicone straps. Whilst it is comfortable to wear, the straps do feel a little cheap. There is also no quick-release mechanism for changing out the straps to something more to your tastes.

The big selling point of the Amazfit T-Rex though is its proven durability. The Huami smartwatch has won 12 military certifications , including the sought-after U.S. Military Standard 810G (MIL-STD-810G) certification. It is also water-resistant up to 5ATM, can survive extreme temperatures between 70°C and -40 °C, and up to 240 hours of damp-heat or 96 hours of salt spray. Naturally, I have not been hanging out in Alaska, diving to the depths of the ocean or trekking through the Sahara desert to put these durability features to the test, but the certifications are there so I don't have to.

A bright OLED display

The 1.3-inch OLED display bright enough for outdoor use and the T-Rex was highly visible  during my testing in what was a pretty sunny spell in Berlin. The screen is covered by Corning Gorilla 3 and has an anti-fingerprint coating. The resolution is 360x360 pixels and the manufacturer says it is capable of displaying 16.7 million colors. There is an always-on-display feature that allows you to permanently display the time, but it will impact battery life.

Overall, the display is nothing to either rave or complain about. It's perfectly suitable for this price point and the main thing you want from a display on a smartwatch that is going to be used outdoors a lot is brightness, and the Amazfit T-Rex ticks that box. Once again, Huami has focused on the thing that matters most, and cut the rest.

A great fitness tracking app runs the show

The Huami smartwatch uses the well-known Amazfit app for pairing and customizations, as well firmware updates and things like downloading new watch faces. There are up to 14 sports modes are available on the T-Rex , covering outdoor running, walking, cycling, treadmill, climbing, trail running, pool swimming, and many more. Switching modes takes just a few clicks, and the buttons really help out here. Compared to the Amazfit GTS, which I use regularly as a running watch, navigation through the OS is quicker when you are on the move thanks to the three additional buttons on the T-Rex.

Huami's self-developed PPG Bio-tracking is one of the key selling points this year. The T-Rex is equipped with the optical sensor, and it runs 24-hour heart rate monitoring. It can remind you when you need to replenish yourself with water or tell you that a light work-out will encourage you to develop healthy habits.

Other features include an advanced activity tracker showing distance, active hours, calories, and steps you achieve, along with sleep monitoring - although nobody is going to sleep with this thing on their wrist, surely!?

Navigation is possible with both GPS and GLONASS, and I found it solid during my testing. One minor frustration I have with the GTS, however, has also carried over to the T-Rex. The smartwatch updates its A-GPS system when it connects to your smartwatch, and the process can take several minutes to complete. It only kicks in when you open the app, and the updates are frequent, so you'll often find yourself waiting to start your exercise until everything has been optimized.

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Up to 20 days of battery life

Battery life is one of the biggest positives I look away from my time with the Amazfit T-Rex. The brand tells me that battery lasts up to 20 days, and even with  GPS activated permanently is can run continuously for up to 20 hours. The 390 mAh battery is not exceptionally huge for a smartwatch, but this thing runs and runs. I started my 7-days of testing with a full charge and ended with 28 percent battery left. This is whilst putting it through a review process where I am testing out features and probably pushing it a little harder than what I would call regular daily use. From what I can tell, however, those battery life claims will stand up.

The story is the same on previous smartwatches I have tested from Huami, and the reason is the brand's own operating system. It makes you realize just how much power-thirsty WearOS is. Sure, there are advantages to Google's smartwatch OS, but battery life is certainly not one of them, and it's only when you branch out to smaller brands that you realize what is possible with properly optimized software.