Amazfit T-Rex Ultra vs Samsung Galaxy Watch8
The Verdict
The Amazfit T-Rex Ultra and Samsung Galaxy Watch8 sit in the same category and end up appealing to slightly different buyers. The Samsung Galaxy Watch8 is the cheaper of the two at $300 versus $450, a difference of about $150. The Samsung Galaxy Watch8 is the newer release, which usually means a faster chipset and longer software support. Amazfit T-Rex Ultra stands out for excellent 20-day battery life with always-on display, while Samsung Galaxy Watch8 is praised for thinnest galaxy watch at 8.6mm. Use the side-by-side spec table below to compare cameras, displays, battery life and connectivity in detail and decide which one fits your priorities.
Who Should Buy
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
Buy the Samsung Galaxy Watch8 if…
- →Thinnest Galaxy Watch at 8.6mm
- →3nm Exynos W1000 processor
- →3000 nits peak brightness
Pros & Cons
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
Samsung Galaxy Watch8
Pros
- Thinnest Galaxy Watch at 8.6mm
- 3nm Exynos W1000 processor
- 3000 nits peak brightness
- Wear OS 6 with Gemini AI assistant
- Dual-frequency GPS
Cons
- $300 starting price for base model
- Battery life varies heavily with AOD
- Limited third-party watch face selection on Wear OS
Full Specifications
| Spec | Amazfit T-Rex Ultra | Samsung Galaxy Watch8 |
|---|---|---|
| Software | Zepp OS 2.0 | Wear OS 6 with Gemini |
| Body | ||
| Weight | 89 g | 28.8 g (40mm) |
| Case material | Stainless steel bezel, fiber-reinforced polymer case | Armor Aluminum |
| Water resistance | 10 ATM, ISO 22810 certified for free-diving to 45m | 5ATM + IP68, MIL-STD-810H |
| Health & Sensors | ||
| ECG | ||
| SpO₂ | ||
| Skin temperature | ||
| Heart rate | ||
| Sleep tracking | ||
| Battery | ||
| Battery life | Up to 20 days typical use, 80 hours GPS | Up to 40 hours |
| Display | ||
| Size | 1.39 inch | 40mm / 44mm |
| Type | AMOLED | Super AMOLED |
| Always-on display | ||
| Resolution | 454 x 454 | 480 x 480 (44mm) |
| Connectivity | ||
| GPS | ||
| NFC | ||
| Wi-Fi | ||
| Cellular | ||
| Bluetooth | 5.0 | 5.3 |
| Processor | ||
| RAM | — | 2 GB |
| Chipset | — | Exynos W1000 (3nm) |
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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.
Explore more in smartwatches, see all Amazfit products or all Samsung products. View full details for the Amazfit T-Rex Ultra or the Samsung Galaxy Watch8.