Amazfit has two of the best value GPS watches on the market right now, and they sit $110 apart. The Active 3 Premium costs $169.99 and punches way above its weight with sapphire glass, offline maps, and dual-band GPS. The T-Rex 3 costs $279 and brings military-grade durability, a bigger battery, and a brighter screen.
Both are excellent. Both undercut Garmin by a wide margin. But they are built for different people. Here is how to figure out which one fits you.
The Short Version
Active 3 Premium is the best budget running watch you can buy. At $169.99, you get a sapphire AMOLED display, dual-band GPS, offline routable maps, lactate threshold tracking, and a stainless steel bezel. It is lighter and more compact than the T-Rex 3, making it better for everyday wear and smaller wrists.
T-Rex 3 is the rugged adventure watch. At $279, you get a bigger 1.5-inch display, 27-day battery life, 42 hours of GPS, military-grade durability ratings, and better outdoor readability. It is the watch you want for trail running, hiking, and multi-day adventures where toughness and battery matter most.
Spec Comparison
| Feature | Active 3 Premium | T-Rex 3 |
|---|---|---|
| Price | $169.99 | $279 |
| Case size | 45mm | 47.4mm |
| Weight | Lighter (stainless steel) | Heavier (polymer + metal) |
| Display | 1.32" AMOLED, 3,000 nits, sapphire | 1.5" AMOLED, 2,000 nits, glass |
| Battery (typical) | 12 days | 27 days |
| Battery (AOD) | ~5 days | ~14 days |
| GPS (continuous) | 24 hours | 42 hours |
| Dual-band GPS | Yes | Yes |
| Offline maps | Yes (routable) | Yes (routable) |
| Water resistance | 5 ATM | 10 ATM (100m) |
| Military tests | No | Yes (15 mil-spec tests) |
| Built-in flashlight | No | Yes |
| Buttons | 4 | 4 |
| Storage | Onboard | Onboard |
| Temp range | Standard | -22F to 158F |
Display: Different Sizes, Different Brightness
The T-Rex 3 has the bigger screen at 1.5 inches. The Active 3 Premium has a smaller but sharper 1.32-inch display with a higher pixel density. Both are AMOLED and both look great.
Where they diverge is peak brightness. The Active 3 Premium hits 3,000 nits, which is brighter than most watches at any price. The T-Rex 3 tops out at 2,000 nits. In practice, both are readable in direct sunlight, but the Active 3 Premium has the edge in raw brightness.
The T-Rex 3's bigger display wins for maps and data fields, though. If you are navigating with offline maps on a trail run, the extra screen real estate makes a real difference. Six data fields fit comfortably on the T-Rex 3. The Active 3 Premium shows four before things feel cramped.
Battery Life: The T-Rex 3 Dominates
This is where the $110 price gap starts to make sense.
The T-Rex 3 delivers 27 days of typical use and 42 hours of continuous GPS. That is Garmin Fenix territory in a watch that costs half as much.
The Active 3 Premium delivers 12 days typical and 24 hours of GPS. Solid for the price, but less than half the T-Rex 3's endurance.
For a daily runner who charges every week or two, either watch works fine. But if you are doing ultra-distance events, multi-day hiking, or just hate charging your watch, the T-Rex 3's battery advantage is significant. 42 hours of GPS covers most 50-mile races. 24 hours does not.
Durability: T-Rex 3 Is Built Different
The T-Rex 3 is the rugged watch here. It passes 15 military-standard durability tests including temperature extremes (-22F to 158F), shock, and humidity. It is rated to 10 ATM (100 meters), meaning you can swim, snorkel, and freedive with it.
The Active 3 Premium is rated to 5 ATM (50 meters). Fine for swimming and showers, but not for diving. It does not carry the military durability ratings.
The T-Rex 3 also has a built-in flashlight, which is one of those features you do not think about until you use it every day. Night runners, campers, and anyone who has ever fumbled for a key in the dark will appreciate it. The Active 3 Premium does not have one.
Running Features: Nearly Identical
This is the interesting part. Both watches share the same core running platform:
- Dual-band GPS with six satellite systems
- Offline routable maps with turn-by-turn navigation
- Zepp Coach AI adaptive training plans
- Heart rate, HRV, VO2 max, and training load tracking
- Automatic Strava upload
- TrainingPeaks, Runna, and Intervals.icu sync
- Lactate threshold tracking
The running experience is very similar on both. The Active 3 Premium actually has a slight edge in GPS brightness readability thanks to the 3,000-nit display. But the T-Rex 3's bigger screen is better for map viewing.
If you are buying purely for running metrics, the Active 3 Premium delivers 95% of the T-Rex 3's capability for $110 less.
Price and Value
Active 3 Premium at $169.99 is the value champion. You are getting sapphire glass, dual-band GPS, offline maps, and a 3,000-nit AMOLED for less than many basic fitness trackers cost. It is genuinely the best budget running watch on the market right now.
T-Rex 3 at $279 costs $110 more and adds a bigger screen, more than double the battery life, military-grade toughness, deeper water resistance, and a built-in flashlight. Those are real, meaningful upgrades if you need them.
Which One Should You Buy?
Get the Active 3 Premium if:
- You are a road runner or gym-goer who wants great value
- You want the lightest, most compact option
- 12 days of battery and 24 hours of GPS covers your activities
- You want sapphire glass and 3,000-nit brightness at the lowest price
- You have smaller wrists and want a watch that does not dominate them
Get the T-Rex 3 if:
- You trail run, hike, or do multi-day adventures
- You need maximum battery life (27 days, 42 hours GPS)
- Military-grade durability and temperature extremes matter to you
- You want a bigger screen for map navigation
- The built-in flashlight is a feature you would actually use
- You swim or freedive and need 10 ATM water resistance
The Bottom Line
Amazfit made two great watches for two different people, and the prices make both easy to recommend.
The Active 3 Premium is the smart money pick for most runners. At $169.99, nothing else touches it on value. Sapphire glass, offline maps, and dual-band GPS at that price is absurd.
The T-Rex 3 is the right call if your watch takes abuse. Trail runs, outdoor adventures, extreme conditions, and long battery needs. The extra $110 buys real capability, not just marketing fluff.
You cannot go wrong with either. Just pick the one that matches what you actually do with your watch.
Active 3 Premium: Buy on Amazon | T-Rex 3: Buy on Amazon