Robust smartwatch with offline navigation: Amazfit T-Rex 3 Pro review

The Amazfit T-Rex 3 Pro impresses in the test with its robustness, the AMOLED display that can also be read in sunlight and many other features for outdoor activities of all kinds. These include not only over 160 sports modes, but also offline navigation including 6-satellite system positioning, an LED flashlight and the usual health features.

The T-Rex 3 Pro also scored points in our test with its generous endurance per battery charge. We had the larger and more enduring model with a 48 mm diameter in our hands. The smaller 44 mm version has a smaller battery.

If you are looking for a robust smartwatch that not only embodies this, but also looks the part, the Amazfi T-Rex 3 Pro is the perfect choice. However, it does not offer modern functions such as ECG or blood pressure measurement. If these are also important to you, you will have to look at the competition from Samsung, Apple or Huawei, but will usually pay more than the MSRP of $400 here.

The T-Rex 3 Pro from Amazfit is a particularly robust smartwatch. The T-Rex 3 Pro is available in two sizes. We tested the 48 mm diameter model, which has been available since IFA 2025 and is quite bulky at around 15 mm thick and comes in either Tactical Black or Black Gold. Recently the manufacturer also launched the smaller 44 mm version, which is available in Tactical Black, Black Gold and Arctic Gold.

The case is made from fiber-reinforced plastic, while the bezel and buttons are made from grade 5 titanium. The bracelet is always made of silicone and can be finely adjusted in length (48 mm: 145 to 210 mm; 44 mm: 140 to 205 mm). It is held in place by a classic pin buckle and can be easily changed using the quick-release fastener. The smaller version measures 20 mm in width, the larger model 22 mm.

The Amazfit T-Rex 3 Pro does not have its own mobile network connection. However, it can be used for Bluetooth telephony via the speaker and microphone in the watch if the connected smartphone is nearby.

During our test under iOS, notifications were transmitted smoothly and immediately, even including photos and stickers. The Zepp app can be used to select which notifications should be sent to the wrist and which should not. The integrated AI can summarize and translate messages. However, there are no reply options available on iOS, as is the case with Android.

The Amazfit T-Rex 3 Pro provides all kinds of health and fitness features on the wrist. These include the usual functions such as 24-hour monitoring of heart rate, blood oxygen saturation, stress and sleep (depending on the setting). The smartwatch doesn't offer ECG and blood pressure measurement, but has installed a sensor for skin temperature.

The focus of the Zepp app is the BioCharge level. This is intended to provide an insight into the wearer's daily performance and takes into account sleep quality and stress, among other things. Data can be synchronized with third-party apps such as Google Fit, Apple Health, Strava, adidas Running and more.

We compared both the heart rate and SpO2 measurements of the Amazfit T-Rex 3 Pro with two reference devices in order to better assess the accuracy of the values.

In terms of heart rate, the smartwatch competes with a Polar H120 chest strap, with whose measurements it largely matches as reference values. The results for the resting heart rate were completely consistent. There were larger discrepancies in the medium heart rate. The measurements here were up to 10 beats below the reference. This leads to an overall deviation of 2.6 percent, which is also reflected in the dynamic curve.

The evaluation of blood oxygen saturation (SpO2) goes in the other direction. Here, the test device overestimates a Braun pulse oximeter 1 almost completely, resulting in an inaccuracy of a good 2.8 percent. However, both deviations are absolutely fine - especially as such measurements are subject to various difficulties, as this article informs.

Another key aspect of the wearable is the monitoring of sleep quality. The watch analyzes your sleep every night (in addition to naps) based on various criteria and evaluates it at the end with a score between 0 and 100 (sleep index).

In addition to sleep duration and sleep times, the sleep phases (deep, REM, awake) and regularity are also included. In addition to the breathing rate, the T-Rex 3 Pro also determines the variability of the heart rate during sleep and evaluates this as well. This also allows conclusions to be drawn about possible hypopnoea.

A brief overview of the previous night can be viewed directly on the watch. As with many other functions, a detailed analysis is provided in the Zepp app. While weekly and monthly trends can be accessed free of charge, some AI features, such as helping you fall asleep with sounds adapted to your heartbeat, can only be used with the paid Aura subscription.

As a robust outdoor smartwatch, sports tracking is of course also an important function of the T-Rex 3 Pro. The manufacturer advertises over 160 sports modes, which are also on board other Amazfit smartwatches. This means that numerous sporting activities can be tracked, even beyond the usual jogging, cycling and swimming. Some sports are recognized automatically.

Depending on the sport, different amounts of data such as speed, distance and time are displayed, whereby the display can be customized. For runners, for example, the watch offers lap times, a virtual pacemaker and a track run mode. Athletes can also benefit from the virtual Zepp Coach, which provides training plans, for example. After training, the wearable determines the level of exertion and provides a recommendation for recovery time.

The 48 mm version we tested is equipped with a 1.5 inch AMOLED. This displays 480 x 480 pixels and thus achieves 322 ppi. The pixel density of the 44 mm version is even slightly higher at 353 PPI. This is because the AMOLED panel installed here displays 466 x 466 pixels on a 1.32-inch diagonal.

According to the manufacturer, the sapphire glass-protected display achieves a peak brightness of 3,000 nits. That is 50 percent more than the 2,000 nits brightness of the T-Rex 3. Although we only measured a value of 2,650 nits in the center, this still benefits readability in very bright environments, for example in direct sunlight.