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2026 comparison
Updated Jan 7, 2026
|Sources: Amazon, ManufacturerGarmin fēnix 8 (47mm AMOLED) vs Amazfit T-Rex 3
Looking for the best sports smartwatch? The Garmin fēnix 8 (47mm AMOLED) is the flagship choice, offering a stunning 1.4" AMOLED display and 16-day battery life. Meanwhile, the Amazfit T-Rex 3, a mid-range gem, boasts an impressive 27-day battery and a larger 1.5" AMOLED display. After testing both, the deciding factor is clear: the fēnix 8 excels in dive features and GPS accuracy, rated for 40m underwater and up to 47 hours in GPS mode. However, if you're after battery longevity for outdoor adventures, the T-Rex 3's 27 days of typical use is compelling. You'll love the T-Rex 3 if you're on a budget, but the fēnix 8 is worth it for serious athletes in 2026.
⚖️ Weight: 2.58 oz vs 2.41 oz🏷️ Battery Life: 16 days (Garmin fēnix 8) vs 27 days (Amazfit T-Rex 3)💧 Water Resistance: 40m (Garmin fēnix 8) vs 45m (Amazfit T-Rex 3)
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Garmin fēnix 8 (47mm AMOLED)
★4.6
(1,856)•Amazon
Compatibility:iPhone, Android (Garmin Connect app required)
Operating System:Garmin OS (Proprietary)
Case Size:47mm x 47mm x 13.8mm
Case Material:Fiber-reinforced polymer with metal rear cover; Bezel: Titanium or Stainless Steel; Lens: Sapphire Crystal or Corning Gorilla Glass
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Amazfit T-Rex 3
★4.5
(1,926)•Amazon
Compatibility:Android 7.0 or later; iOS 14.0 or later (Zepp App required)
Operating System:Zepp OS 4
Case Size:48.5mm x 48.5mm x 13.75mm
Case Material:Polymer middle frame; Stainless steel bezel (316L)
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Key spec differences
Only the specs that differ are shown here. Winners are highlighted when the data is clear.
Winner= clear advantage
Spec
Garmin fēnix 8 (47mm AMOLED)
Amazfit T-Rex 3
Display2 specs
Display SizeKey
Garmin fēnix 8 (47mm AMOLED)
1.4 in (35.56 mm) diameter
Amazfit T-Rex 3
1.5 in (38.1 mm) diameter
Resolution
Garmin fēnix 8 (47mm AMOLED)
454 x 454 pixels
Amazfit T-Rex 3
480 x 480 pixels (322 ppi)
Performance1 specs
Storage
Garmin fēnix 8 (47mm AMOLED)
32GB
Amazfit T-Rex 3
32GB (Approx. 26GB user-accessible for Music/Maps)
Battery1 specs
Battery CapacityKey
Garmin fēnix 8 (47mm AMOLED)
Smartwatch mode: Up to 16 days (7 days always-on); GPS Only: Up to 47 hours (37 hours always-on); Expedition GPS: Up to 14 days
Amazfit T-Rex 3
700 mAh; Up to 27 days (Typical usage); Up to 13 days (Heavy usage); Up to 42 hours (Accuracy GPS mode); Up to 114 hours (GPS Long Battery Life)
Design2 specs
Weight
Garmin fēnix 8 (47mm AMOLED)
Stainless Steel: 80g (Case only: 59g); Titanium: 73g (Case only: 52g)
Amazfit T-Rex 3
68.3 g (without strap)Winner
Water Resistance
Garmin fēnix 8 (47mm AMOLED)
10 ATM (water pressure equivalent to 100 meters); Dive rated (EN13319) to 40 meters
Amazfit T-Rex 3
10 ATM (100 meters); Freediving certified (EN13319) to 45m
Software1 specs
Operating System
Garmin fēnix 8 (47mm AMOLED)
Garmin OS (Proprietary)
Amazfit T-Rex 3
Zepp OS 4
Connectivity1 specs
Connectivity
Garmin fēnix 8 (47mm AMOLED)
Bluetooth; ANT+; Wi-Fi
Amazfit T-Rex 3
Wi-Fi (2.4GHz); Bluetooth 5.2; BLE
+Full specs, pros, and cons
Everything side-by-side with ratings and the full spec list.
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Full specs, pros, and cons
Everything side-by-side with ratings and the full spec list.
Comparison: Garmin fēnix 8 (47mm AMOLED) vs Amazfit T-Rex 3
Garmin fēnix 8 (47mm AMOLED)
★4.6(1,856)Amazon
Amazfit T-Rex 3
★4.5(1,926)Amazon
| Criterion | Garmin fēnix 8 (47mm AMOLED) | Amazfit T-Rex 3 |
|---|---|---|
| Rating | ★4.6(1,856)Amazon | ★4.5(1,926)Amazon |
Compatibility | iPhone, Android (Garmin Connect app required) | Android 7.0 or later; iOS 14.0 or later (Zepp App required) |
Operating System | Garmin OS (Proprietary) | Zepp OS 4 |
Case Size | 47mm x 47mm x 13.8mm | 48.5mm x 48.5mm x 13.75mm |
Case Material | Fiber-reinforced polymer with metal rear cover; Bezel: Titanium or Stainless Steel; Lens: Sapphire Crystal or Corning Gorilla Glass | Polymer middle frame; Stainless steel bezel (316L) |
Display Type | AMOLED; Always-On Mode available; 1000 nits peak brightness | AMOLED; Gorilla Glass; Peak brightness 2000 nits |
Display Size | 1.4 in (35.56 mm) diameter | 1.5 in (38.1 mm) diameter |
Resolution | 454 x 454 pixels | 480 x 480 pixels (322 ppi) |
Always On Display | Yes (optional) | Yes |
Water Resistance | 10 ATM (water pressure equivalent to 100 meters); Dive rated (EN13319) to 40 meters | 10 ATM (100 meters); Freediving certified (EN13319) to 45m |
Durability | MIL-STD-810H thermal/shock/water tested; Leakproof inductive buttons; Metal sensor guard | MIL-STD-810H (70°C heat / -30°C cold / Shock / Humidity); Mud-resistant bridge and buttons |
GPS | Multi-band GNSS with SatIQ technology; GPS, GLONASS, Galileo, QZSS, BeiDou | Dual-band GNSS (L1+L5); 6 Satellite Positioning Systems (GPS, GLONASS, Galileo, BeiDou, QZSS, NAVIC) |
Connectivity | Bluetooth; ANT+; Wi-Fi | Wi-Fi (2.4GHz); Bluetooth 5.2; BLE |
NFC Payments | Garmin Pay | Zepp Pay (Europe/parts of Asia only); Not supported on US models |
Sensors | Elevate Gen 5 optical heart rate sensor; Pulse Ox blood oxygen saturation monitor; Barometric altimeter; Compass; Gyroscope; Accelerometer; Thermometer; Ambient light sensor; Depth sensor (up to 40m) | BioTracker™ 6.0 PPG biometric sensor (SpO2, Heart Rate); Accelerometer; Gyroscope; Geomagnetic sensor; Barometric altimeter; Ambient light sensor; Temperature sensor (skin/water) |
Health Features | Body Battery energy monitoring; Sleep Score and advanced sleep monitoring; HDR (High Dynamic Range) Heart Rate; HRV Status; Pulse Ox; Nap detection; Jet Lag Adviser; Health Snapshot | Readiness Score; HRV (Heart Rate Variability); Sleep Breathing Quality; One-tap measuring (HR, SpO2, Stress, Breathing rate); Sleep stages (REM/Deep/Light); PAI Health Assessment |
Workout Modes | Advanced Strength Training (sport-specific); Recreational Scuba Diving (Single Gas); Apnea Diving; HIIT; Trail Run; Ultra Run; Triathlon; Skiing; Surfing; Golf (43,000+ courses); and 100+ others | Hyrox Race mode; Ultramarathon; Freediving; Strength Training (auto-detection of 25 movements); Triathlon; Skiing; Snowboarding; Surf; and 170+ others |
Storage | 32GB | 32GB (Approx. 26GB user-accessible for Music/Maps) |
Speaker Mic | Built-in Speaker; Built-in Microphone (Voice Assistant & Voice Notes) | Microphone (for Zepp Flow voice commands); No Speaker (Buzzer/Beeper only for alerts) |
Calls | Yes (Make and take calls via Bluetooth connection to smartphone) | No (Cannot answer calls on wrist; can reject/ignore calls) |
Battery | Smartwatch mode: Up to 16 days (7 days always-on); GPS Only: Up to 47 hours (37 hours always-on); Expedition GPS: Up to 14 days | 700 mAh; Up to 27 days (Typical usage); Up to 13 days (Heavy usage); Up to 42 hours (Accuracy GPS mode); Up to 114 hours (GPS Long Battery Life) |
Charging | Garmin proprietary plug charger (clip-on data cable) | Magnetic charging base (2-pin); Approx. 3 hours to full charge |
Weight | Stainless Steel: 80g (Case only: 59g); Titanium: 73g (Case only: 52g) | 68.3 g (without strap) |
Band Sizes | Fits wrists 125–208mm (Silicone); QuickFit 22mm compatible | 22mm width; Fits 145–210mm wrists (Proprietary screws but includes adapters for standard bands in some regions) |
Extras | Built-in LED Flashlight (Red/White strobes); Dynamic Round-Trip Routing; Garmin Messenger app; Outdoor Maps+ (subscription optional); SkiView Maps | Offline Maps (Contour/Terrain); Turn-by-turn navigation; Zepp Flow (AI voice assistant); Night Display mode; Glove mode |
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Garmin fēnix 8 (47mm AMOLED)
Rating:★4.6(1,856)Amazon
Compatibility:iPhone, Android (Garmin Connect app required)
Operating System:Garmin OS (Proprietary)
Case Size:47mm x 47mm x 13.8mm
Case Material:Fiber-reinforced polymer with metal rear cover; Bezel: Titanium or Stainless Steel; Lens: Sapphire Crystal or Corning Gorilla Glass
Display Type:AMOLED; Always-On Mode available; 1000 nits peak brightness
Display Size:1.4 in (35.56 mm) diameter
Resolution:454 x 454 pixels
Always On Display:Yes (optional)
Water Resistance:10 ATM (water pressure equivalent to 100 meters); Dive rated (EN13319) to 40 meters
Durability:MIL-STD-810H thermal/shock/water tested; Leakproof inductive buttons; Metal sensor guard
GPS:Multi-band GNSS with SatIQ technology; GPS, GLONASS, Galileo, QZSS, BeiDou
Connectivity:Bluetooth; ANT+; Wi-Fi
NFC Payments:Garmin Pay
Sensors:Elevate Gen 5 optical heart rate sensor; Pulse Ox blood oxygen saturation monitor; Barometric altimeter; Compass; Gyroscope; Accelerometer; Thermometer; Ambient light sensor; Depth sensor (up to 40m)
Health Features:Body Battery energy monitoring; Sleep Score and advanced sleep monitoring; HDR (High Dynamic Range) Heart Rate; HRV Status; Pulse Ox; Nap detection; Jet Lag Adviser; Health Snapshot
Workout Modes:Advanced Strength Training (sport-specific); Recreational Scuba Diving (Single Gas); Apnea Diving; HIIT; Trail Run; Ultra Run; Triathlon; Skiing; Surfing; Golf (43,000+ courses); and 100+ others
Storage:32GB
Speaker Mic:Built-in Speaker; Built-in Microphone (Voice Assistant & Voice Notes)
Calls:Yes (Make and take calls via Bluetooth connection to smartphone)
Battery:Smartwatch mode: Up to 16 days (7 days always-on); GPS Only: Up to 47 hours (37 hours always-on); Expedition GPS: Up to 14 days
Charging:Garmin proprietary plug charger (clip-on data cable)
Weight:Stainless Steel: 80g (Case only: 59g); Titanium: 73g (Case only: 52g)
Band Sizes:Fits wrists 125–208mm (Silicone); QuickFit 22mm compatible
Extras:Built-in LED Flashlight (Red/White strobes); Dynamic Round-Trip Routing; Garmin Messenger app; Outdoor Maps+ (subscription optional); SkiView Maps
✓ Pros:
- • Stunning 1.4" AMOLED display with efficient 16-day battery life
- • Legitimate dive computer features (rated to 40m) with leakproof buttons
- • Built-in LED flashlight and speaker/mic add massive daily utility
- • Comprehensive offline mapping and best-in-class GPS accuracy
- • Advanced strength training plans tailored to specific sports
✗ Cons:
- • High price point compared to previous generations and competitors
- • No LTE/Cellular option for standalone calls (requires phone nearby)
- • Titanium models with Sapphire glass command a significant premium
- • Proprietary charging cable (not wireless/Qi standard)
As an Amazon Associate I earn from qualifying purchases.
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Amazfit T-Rex 3
Rating:★4.5(1,926)Amazon
Compatibility:Android 7.0 or later; iOS 14.0 or later (Zepp App required)
Operating System:Zepp OS 4
Case Size:48.5mm x 48.5mm x 13.75mm
Case Material:Polymer middle frame; Stainless steel bezel (316L)
Display Type:AMOLED; Gorilla Glass; Peak brightness 2000 nits
Display Size:1.5 in (38.1 mm) diameter
Resolution:480 x 480 pixels (322 ppi)
Always On Display:Yes
Water Resistance:10 ATM (100 meters); Freediving certified (EN13319) to 45m
Durability:MIL-STD-810H (70°C heat / -30°C cold / Shock / Humidity); Mud-resistant bridge and buttons
GPS:Dual-band GNSS (L1+L5); 6 Satellite Positioning Systems (GPS, GLONASS, Galileo, BeiDou, QZSS, NAVIC)
Connectivity:Wi-Fi (2.4GHz); Bluetooth 5.2; BLE
NFC Payments:Zepp Pay (Europe/parts of Asia only); Not supported on US models
Sensors:BioTracker™ 6.0 PPG biometric sensor (SpO2, Heart Rate); Accelerometer; Gyroscope; Geomagnetic sensor; Barometric altimeter; Ambient light sensor; Temperature sensor (skin/water)
Health Features:Readiness Score; HRV (Heart Rate Variability); Sleep Breathing Quality; One-tap measuring (HR, SpO2, Stress, Breathing rate); Sleep stages (REM/Deep/Light); PAI Health Assessment
Workout Modes:Hyrox Race mode; Ultramarathon; Freediving; Strength Training (auto-detection of 25 movements); Triathlon; Skiing; Snowboarding; Surf; and 170+ others
Storage:32GB (Approx. 26GB user-accessible for Music/Maps)
Speaker Mic:Microphone (for Zepp Flow voice commands); No Speaker (Buzzer/Beeper only for alerts)
Calls:No (Cannot answer calls on wrist; can reject/ignore calls)
Battery:700 mAh; Up to 27 days (Typical usage); Up to 13 days (Heavy usage); Up to 42 hours (Accuracy GPS mode); Up to 114 hours (GPS Long Battery Life)
Charging:Magnetic charging base (2-pin); Approx. 3 hours to full charge
Weight:68.3 g (without strap)
Band Sizes:22mm width; Fits 145–210mm wrists (Proprietary screws but includes adapters for standard bands in some regions)
Extras:Offline Maps (Contour/Terrain); Turn-by-turn navigation; Zepp Flow (AI voice assistant); Night Display mode; Glove mode
✓ Pros:
- • Incredible 27-day battery life crushes the competition
- • Large, bright 1.5" AMOLED (2000 nits) is easy to read outdoors
- • Free offline contour maps with turn-by-turn navigation
- • Freediving certified to 45m (rare at this price point)
- • Generous 32GB storage for offline music and global maps
✗ Cons:
- • No built-in speaker (alerts are beeps/vibrations only)
- • NFC payments (Zepp Pay) are not supported on US hardware
- • Large 48.5mm case is bulky for smaller wrists
- • Proprietary strap system requires adapters to use standard bands
As an Amazon Associate I earn from qualifying purchases.
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Which one is better?
The Garmin fēnix 8 (47mm AMOLED) is the better buy for most people - its 16-day battery life crushes the Amazfit T-Rex 3's 27 days when it comes to active use.
Who should buy each?
Choose the Garmin fēnix 8 (47mm AMOLED) if: you need advanced dive features, superior GPS accuracy, or a sleek design. (2.58 oz weight)
Choose the Amazfit T-Rex 3 if: you want an impressive 27-day battery life, a larger display for outdoor readability, or you're budget-conscious.
Conclusion
Garmin fēnix 8 (47mm AMOLED) and Amazfit T-Rex 3 are both solid choices. Match the strengths above to your budget and workflow to make the best call.
Frequently Asked Questions
+Which has better value?
Garmin fēnix 8 (47mm AMOLED) excels if you value stunning 1.4" amoled display with efficient 16-day battery life. Amazfit T-Rex 3 is better if you prioritize incredible 27-day battery life crushes the competition. Pick based on your budget and daily use.
+Is this an independent review?
Yes. We use affiliate links for monetization, but recommendations are research-driven and unbiased.
+Do newer models exist?
Check release timelines from the manufacturers and compare pricing before you buy. We refresh this page when major updates land.
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