Amazfit T-Rex Ultra vs Garmin Fenix 8 Pro
The Verdict
The Amazfit T-Rex Ultra and Garmin Fenix 8 Pro sit in the same category and end up appealing to slightly different buyers. The Amazfit T-Rex Ultra is the cheaper of the two at $450 versus $1,200, a difference of about $750. The Garmin Fenix 8 Pro 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 Garmin Fenix 8 Pro is praised for inreach satellite + cellular connectivity. 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 Garmin Fenix 8 Pro if…
- →inReach satellite + cellular connectivity
- →Up to 27 days battery (AMOLED)
- →MicroLED display option ($1999)
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
Garmin Fenix 8 Pro
Pros
- inReach satellite + cellular connectivity
- Up to 27 days battery (AMOLED)
- MicroLED display option ($1999)
- LTE voice calls and two-way messaging
- Built for extreme outdoor adventures
Cons
- $1199 starting price ($1999 MicroLED)
- No ECG sensor
- Garmin OS lacks app ecosystem of watchOS/Wear OS
- 73g is heavy on the wrist
Full Specifications
| Spec | Amazfit T-Rex Ultra | Garmin Fenix 8 Pro |
|---|---|---|
| Software | Zepp OS 2.0 | Garmin OS |
| Body | ||
| Weight | 89 g | 73 g (47mm AMOLED) |
| Case material | Stainless steel bezel, fiber-reinforced polymer case | Titanium bezel, fiber-reinforced polymer |
| Water resistance | 10 ATM, ISO 22810 certified for free-diving to 45m | 10 ATM |
| Health & Sensors | ||
| ECG | ||
| SpO₂ | ||
| Skin temperature | ||
| Heart rate | ||
| Sleep tracking | ||
| Battery | ||
| Battery life | Up to 20 days typical use, 80 hours GPS | Up to 27 days (AMOLED smartwatch mode) |
| Display | ||
| Size | 1.39 inch | 47mm / 51mm |
| Type | AMOLED | AMOLED or MicroLED |
| Always-on display | ||
| Resolution | 454 x 454 | — |
| Connectivity | ||
| GPS | ||
| NFC | ||
| Wi-Fi | ||
| Cellular | ||
| Bluetooth | 5.0 | 5.2 |
| Processor | ||
| Chipset | — | Garmin proprietary |
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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 Garmin products. View full details for the Amazfit T-Rex Ultra or the Garmin Fenix 8 Pro.