Amazfit GTS 4 vs Amazfit T-Rex Ultra
The Verdict
Both smartwatches run Zepp OS 2.0 and offer AMOLED displays with always-on capability, but serve different user needs. Amazfit GTS 4 excels as a lightweight daily driver at 27g with a compact 42mm form factor, dual-band GPS, Wi-Fi connectivity, and solid 8-day battery life,ideal for fitness enthusiasts seeking convenience. Amazfit T-Rex Ultra targets rugged adventurers with its 89g titanium-reinforced construction, military-grade durability (10 ATM certification, free-diving rated to 45m), and exceptional 20-day battery endurance. Both lack ECG and skin temperature sensors. GTS 4 delivers better portability and everyday wearability at half the price, while T-Rex Ultra justifies premium cost through superior durability, extended battery performance, and adventure-ready engineering. Choose GTS 4 for balanced performance and value; select T-Rex Ultra if extreme conditions and extended autonomy matter most.
Who Should Buy
Buy the Amazfit GTS 4 if…
- →Large 1.75" AMOLED display is bright and vivid for the price
- →Dual-band GPS provides accurate outdoor tracking rivaling Garmin
- →Ultra-lightweight at 27 g — one of the lightest smartwatches available
Buy the Amazfit T-Rex Ultra if…
- →Excellent 20-day battery life with always-on display
- →Dual-band six-satellite GPS for high accuracy
- →Rugged design with 15 military-grade certifications
Category Scores
Pros & Cons
Amazfit GTS 4
Pros
- Large 1.75" AMOLED display is bright and vivid for the price
- Dual-band GPS provides accurate outdoor tracking rivaling Garmin
- Ultra-lightweight at 27 g — one of the lightest smartwatches available
- 8-day battery comfortably outlasts Apple Watch and Galaxy Watch
- 150+ sport modes cover virtually every activity
Cons
- Zepp OS has a very limited third-party app ecosystem
- No NFC for contactless payments in most markets
- Notification interaction is basic — can't reply to messages
- Build quality feels less premium than Apple or Samsung at this price
Amazfit T-Rex Ultra
Pros
- Excellent 20-day battery life with always-on display
- Dual-band six-satellite GPS for high accuracy
- Rugged design with 15 military-grade certifications
- Free-diving rated to 45 meters
- Offline maps with route import support
Cons
- No ECG, skin temperature, or NFC payments
- No Wi-Fi or cellular connectivity
- Zepp OS app ecosystem is limited
- Heavier than most smartwatches at 89g
- No third-party app store
Full Specifications
| Spec | Amazfit GTS 4 | Amazfit T-Rex Ultra |
|---|---|---|
| Software | Zepp OS 2.0 | Zepp OS 2.0 |
| Body | ||
| Weight | 27 g (without strap) | 89 g |
| Case material | Aluminum alloy | Stainless steel bezel, fiber-reinforced polymer case |
| Water resistance | 5ATM | 10 ATM, ISO 22810 certified for free-diving to 45m |
| Health & Sensors | ||
| ECG | ||
| SpO₂ | ||
| Skin temperature | ||
| Heart rate | ||
| Sleep tracking | ||
| Battery | ||
| Battery life | Up to 8 days (typical usage) | Up to 20 days typical use, 80 hours GPS |
| Display | ||
| Size | 42mm (1.75 inches) | 1.39 inch |
| Type | AMOLED | AMOLED |
| Always-on display | ||
| Resolution | 390 x 450 | 454 x 454 |
| Processor | ||
| Chipset | Huami custom processor | — |
| Connectivity | ||
| GPS | ||
| NFC | ||
| Wi-Fi | ||
| Cellular | ||
| Bluetooth | 5.0 | 5.0 |
Related Comparisons
This comparison is based on verified manufacturer specifications covering display, performance, camera, battery, and build quality. Scores are generated by analyzing specs across weighted categories on a 10-point scale. Learn more about our methodology.
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