Amazfit T-Rex Ultra vs Garmin Fenix 7
The Verdict
Amazfit T-Rex Ultra and Garmin Fenix 7 both deliver rugged outdoor smartwatches with 10 ATM water resistance, multi-day battery life, and comprehensive health tracking. Amazfit's T-Rex Ultra shines with a vibrant 454x454 AMOLED display and exceptional 20-day battery in typical use, ideal for users prioritizing screen quality and minimal charging. Garmin's Fenix 7 counters with multi-band GPS (GPS/GLONASS/Galileo), integrated Wi-Fi and NFC for contactless payments, plus superior expedition mode reaching 40 days,critical for serious outdoor athletes. The Fenix 7's MIP transflective display excels in direct sunlight but appears dimmer indoors compared to AMOLED. At $449.99 versus $699, Amazfit offers exceptional value for general fitness and casual adventuring. However, Garmin's ecosystem, advanced navigation capabilities, and specialized outdoor features justify the premium for dedicated hikers, climbers, and expedition planners. Choose Amazfit for everyday versatility and display brilliance; select Fenix 7 for serious backcountry performance.
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 7 if…
- →Multi-week battery life is in a completely different class from Apple/Samsung
- →Multi-band GPS is the most accurate satellite positioning on any watch
- →Built-in maps with TopoActive and Ski Maps for outdoor adventures
Category Scores
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 7
Pros
- Multi-week battery life is in a completely different class from Apple/Samsung
- Multi-band GPS is the most accurate satellite positioning on any watch
- Built-in maps with TopoActive and Ski Maps for outdoor adventures
- Touchscreen added alongside traditional button navigation
- Garmin Connect ecosystem is the gold standard for athletic training
Cons
- MIP display looks dated compared to AMOLED smartwatches
- No cellular or call capability — strictly a fitness/outdoor watch
- Heavy at 79 g — noticeable during sleep and daily wear
- $699 starting price, with Solar and Sapphire models costing more
Full Specifications
| Spec | Amazfit T-Rex Ultra | Garmin Fenix 7 |
|---|---|---|
| Software | Zepp OS 2.0 | Garmin OS (Connect IQ) |
| Body | ||
| Weight | 89 g | 79 g |
| Case material | Stainless steel bezel, fiber-reinforced polymer case | Fiber-reinforced polymer with stainless steel bezel |
| Water resistance | 10 ATM, ISO 22810 certified for free-diving to 45m | 10ATM |
| Health & Sensors | ||
| ECG | ||
| SpO₂ | ||
| Skin temperature | ||
| Heart rate | ||
| Sleep tracking | ||
| Battery | ||
| Battery life | Up to 20 days typical use, 80 hours GPS | Up to 18 days (smartwatch), 57 hrs GPS, 40 days expedition GPS |
| Display | ||
| Size | 1.39 inch | 47mm (1.3 inches) |
| Type | AMOLED | MIP (memory-in-pixel) transflective |
| Always-on display | ||
| Resolution | 454 x 454 | 260 x 260 |
| Connectivity | ||
| GPS | ||
| NFC | ||
| Wi-Fi | ||
| Cellular | ||
| Bluetooth | 5.0 | 5.0 |
| Processor | ||
| Chipset | — | Garmin custom processor |
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.
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 7.