AmazFit T-Rex 3 Pro Review: Budget-friendly best watch for runners

By Henry Howard

After years of loyalty to other major watch brands, I am super impressed with a newcomer to the scene. The AmazFit T-Rex 3 Pro is a GPS running watch that punches well above its weight class at just $279.

I conducted extensive testing on roads, trails, in cities and rural areas and everything in between, I have a good handle on why the AmazFit T-Rex 3 Pro is the best value running watch. It struck me as the same feeling I had when I first tried Coros when it burst onto the scene nearly a decade ago.

Over the past 15 years, I have worn and tested running watches from Garmin and Suunto, as well as Coros. Pound for pound, the AmazFit T-Rex 3 Pro is the best watch for runners looking for premium features in a budget-friendly option.

First impressions: Built to last

The T-Rex 3 Pro immediately feels substantial. Available in both 44mm and 48mm sizes, this watch caters to different wrist sizes without compromising on features. The addition of titanium bezel and sapphire glass gives it a premium feel that belies its budget-friendly price point. At 68.3g for the 48mm version, it’s light enough for all-day wear but sturdy enough to handle whatever your training throws at it.

The 1.5” AMOLED touchscreen is gorgeous – vibrant, easy to read especially in the dark, and responsive even when wet with sweat, snow or sleet. I have had issues seeing the numbers on my Coros watch but the T-Rex 3 Pro is clear and easy to read. I’ve been running with the always-on display enabled, and the battery life remains stellar (more on that later).

The running experience: Where the T-Rex 3 Pro shines

For runners, the T-Rex 3 Pro delivers where it matters most. The multiband/dual-frequency GPS has been remarkably accurate across my training runs, whether I’m navigating downtown streets flanked by tall buildings or hitting remote trail systems. Distance tracking has been consistently spot-on, and the pace data is reliable enough to trust during intervals and tempo work.

One thing that really impressed me was on my first run from home. The T-Rex 3 Pro GPS immediately found my location and was ready to start before I was. Even though I have started a run hundreds of times from my house, the Coros still needs more time.

The T-Rex 3 Pro optical heart rate sensor is another solid feature. It tracks steady-state efforts beautifully and responds quickly to interval changes. During a 90-minute progression run with intervals, it stayed locked onto my heart rate with minimal drift. While I don’t personally rely on heart rate training, this is a huge win for runners who prefer wrist-based heart rate monitoring.

The watch offers solid structured workout support, including customizable intervals based on time or distance. You can set up repeats, recovery periods, and add warm-up/cool-down sections. While you can’t import workouts from TrainingPeaks (a limitation for some athletes), the on-watch interval builder works well for most running workouts.

Standout features for runners

Battery life: The best among running watches

This is where the T-Rex 3 Pro absolutely demolishes the competition. I’m consistently getting multiple full weeks of battery life with daily runs averaging 1-2 hours, always-on display enabled.

For longer efforts, AmazFit claims up to 180 hours of GPS battery depending on the mode you select. In an era where charging your watch frequently has become the norm, this is genuinely liberating.

Brilliant charging station

On those rare occasions when you do need to charge the watch, its magnetic charging dock is ingenious. It clips securely onto the watch and connects via USB-C (not included but we all have too many of these already).

No more trying to keep my Coros watch and its charging cable properly connected during a charge, which has been frustrating.

The data: intuitive and comprehensive

The interface is refreshingly intuitive. Data fields are customizable (up to six per page), and you can swipe through multiple screens during your run. The watch tracks all the metrics serious runners expect: pace, distance, cadence, heart rate, elevation and more.

Training load calculations have been consistent and useful for managing my weekly mileage.

Post-run, the Zepp app provides detailed analytics including splits, elevation profiles and heart rate zones. The data automatically syncs to Strava, making it easy to share your runs with your training community.

Built-in flashlight

As a runner who often squeezes in zero dark thirty miles, the built-in flashlight is surprisingly useful. It’s bright enough to find something in your car at a dark trailhead or help you find your keys in your gym bag. It’s one of those features you don’t think you need until you have it.

Two size options

The 44mm option, which I chose, is a welcome addition for runners with smaller wrists who want serious features without the oversized watch look.

Room for improvement

No watch is perfect, and the T-Rex 3 Pro has some quirks.

The navigation features, while functional for following pre-loaded routes, aren’t as polished as what you’ll find on premium Garmin or Coros watches. The maps can be confusing (water bodies don’t always render clearly), and creating routes within the app isn’t possible. You’ll need to use a third-party service like Komoot or Strava.

For me, that has not been a big deal as I generally run similar routes or prefer to explore new-to-me areas myself. If you rely on such maps, the question is whether it’s worth the extra cost of a higher-tier watch.

Outdoor cycling heart rate can be hit-or-miss, particularly on descents or rough terrain. For me, this is not an issue personally. But if you use heart rate as part of your cycling workouts, you might want to pair the watch with a chest strap for better accuracy.

The verdict: AmazFit T-Rex 3 Pro is an exceptional value for runners

At $279 (save 10% at this link with my discount code: RUNSPIRITED), the AmazFit T-Rex 3 Pro offers incredible value for runners.

The T-Rex 3 Pro nails the fundamentals: accurate GPS, solid heart rate monitoring for running, excellent battery life, and a durable build quality. The minor software quirks and navigation limitations are easy to overlook when you consider the price point and battery performance.

Is it a “Garmin killer”? Not quite – the ecosystem, software polish, and advanced features still favor the premium brands. But for runners who want reliable tracking, excellent battery life, and solid build quality without spending $500 to $800, the T-Rex 3 Pro watch is the best option.

After years with premium brands, I could not be more pleased with AmazFit. The T-Rex 3 Pro has convinced me that you don’t need to break the bank for a running watch that can handle serious training. It’s earned its place as my daily companion, and I suspect it’ll convert plenty of other runners too.

Frequently Asked Questions: AmazFit T-Rex 3 Pro

Q: How accurate is the GPS for running?

A: Exceptionally accurate. In my testing across roads, trails and urban environments, the multiband GPS has been consistently reliable for both distance and pace tracking.

Q: Can I use the watch for trail running?

A: Absolutely. The T-Rex 3 Pro handles trail running beautifully with accurate GPS tracking and excellent battery life for longer adventures. The 45-meter depth gauge and rugged build make it suitable for various outdoor conditions.

Q: How long does the battery actually last?

A: With daily runs and always-on display, I’m measuring the time in between charges in weeks not days. For GPS-only activities, you can expect 40+ hours depending on the accuracy mode selected.

Q: Does it work with running power meters like Stryd?

A: Yes, the watch supports external running power meters via Bluetooth connectivity.

Q: Can I receive smartphone notifications during runs?

A: Yes, but the gesture recognition for viewing notifications can be finicky, sometimes requiring exaggerated wrist movements to activate the display.

Q: Is the watch suitable for swimming?

A: Yes, though I have not tested it. The watch is water-resistant and includes swim tracking modes. The optical heart rate works during pool swimming, though open water GPS tracking can be less accurate than dedicated swim watches.

Q: Can I create custom workouts on the watch?

A: You can create structured interval workouts with the watch and app, including warm-up, repeats, recovery, and cool-down segments. However, you cannot import workouts from platforms like TrainingPeaks.

Q: How does it compare to Garmin or Coros watches?

A: The T-Rex 3 Pro exceeds premium brands in GPS accuracy and battery life, and beats them significantly on price. However, it lacks the ecosystem depth, advanced training features, and software polish of those premium options. For the majority of runners, the AmazFit T-Rex 3 Pro is excellent and incredibly useful for regular daily training. For runners who focus more on mountain running and require the advanced analytics and features, premium brands still have the edge but come with a higher price point.

Q: What comes in the box?

A: The watch, magnetic charging dock and user manual.

Q: Can I load music onto the watch?

A: The watch has music controls for your phone but doesn’t store music locally.