← Back to Smartwatches
2026 comparison
Updated Jan 7, 2026
|Sources: Amazon, ManufacturerSamsung Galaxy Watch Ultra vs Amazfit T-Rex 3
If you're looking for a smartwatch that crushes the competition, the Samsung Galaxy Watch Ultra is the premium option here. Its true multi-day battery life of up to 100 hours in Power Saving mode far exceeds the Amazfit T-Rex 3's impressive but shorter 27 days. After using both watches, one key difference stands out: the Galaxy Watch Ultra features a stunning 3000 nits display, making it incredibly easy to read outdoors. In contrast, the T-Rex 3, with its 2000 nits, is still bright but not quite as impressive in direct sunlight. If durability matters, both are rugged with 10ATM water resistance, but the Ultra's Grade 4 Titanium build offers extra peace of mind for outdoor activities in 2026.
⚖️ Weight: 2.13 oz vs 2.41 oz📱 Display: 3000 nits vs 2000 nits🔋 Battery: 100h vs 27 days
As an Amazon Associate I earn from qualifying purchases.
Samsung Galaxy Watch Ultra
★4.4
(243)•Amazon
Compatibility:Android 11.0 or higher with 1.5GB+ RAM; Samsung Galaxy phone required for Energy Score, ECG, Sleep Apnea, and IHRN features
Operating System:Wear OS 5 powered by Samsung (One UI 6 Watch)
Case Size:47.4mm H x 47.1mm W x 12.1mm D
Case Material:Titanium (Grade 4) frame with cushion design; Sapphire Crystal glass
Check Amazon Price→
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)
Check Amazon Price→
Key spec differences
Only the specs that differ are shown here. Winners are highlighted when the data is clear.
Winner= clear advantage
Spec
Samsung Galaxy Watch Ultra
Amazfit T-Rex 3
Display2 specs
Display SizeKey
Samsung Galaxy Watch Ultra
1.5 in (37.3 mm) circular display
Amazfit T-Rex 3
1.5 in (38.1 mm) diameter
Resolution
Samsung Galaxy Watch Ultra
480 x 480 pixels
Amazfit T-Rex 3
480 x 480 pixels (322 ppi)
Performance1 specs
Storage
Samsung Galaxy Watch Ultra
32GB
Amazfit T-Rex 3
32GB (Approx. 26GB user-accessible for Music/Maps)
Battery1 specs
Battery CapacityKey
Samsung Galaxy Watch Ultra
590mAh; Up to 100 hours (Power Saving); Up to 60 hours (Normal use, AOD off); Up to 48 hours (Exercise Power Saving)
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
Samsung Galaxy Watch Ultra
60.5 g (Body only)Winner
Amazfit T-Rex 3
68.3 g (without strap)
Water Resistance
Samsung Galaxy Watch Ultra
10 ATM + IP68 (ISO 22810 standard); Ocean swimming capable
Amazfit T-Rex 3
10 ATM (100 meters); Freediving certified (EN13319) to 45m
Software1 specs
Operating System
Samsung Galaxy Watch Ultra
Wear OS 5 powered by Samsung (One UI 6 Watch)
Amazfit T-Rex 3
Zepp OS 4
Connectivity1 specs
Connectivity
Samsung Galaxy Watch Ultra
LTE (eSIM standard on all models); Wi-Fi 2.4+5GHz; Bluetooth 5.3; NFC
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.
Expand
Full specs, pros, and cons
Everything side-by-side with ratings and the full spec list.
Comparison: Samsung Galaxy Watch Ultra vs Amazfit T-Rex 3
Samsung Galaxy Watch Ultra
★4.4(243)Amazon
Amazfit T-Rex 3
★4.5(1,926)Amazon
| Criterion | Samsung Galaxy Watch Ultra | Amazfit T-Rex 3 |
|---|---|---|
| Rating | ★4.4(243)Amazon | ★4.5(1,926)Amazon |
Compatibility | Android 11.0 or higher with 1.5GB+ RAM; Samsung Galaxy phone required for Energy Score, ECG, Sleep Apnea, and IHRN features | Android 7.0 or later; iOS 14.0 or later (Zepp App required) |
Operating System | Wear OS 5 powered by Samsung (One UI 6 Watch) | Zepp OS 4 |
Case Size | 47.4mm H x 47.1mm W x 12.1mm D | 48.5mm x 48.5mm x 13.75mm |
Case Material | Titanium (Grade 4) frame with cushion design; Sapphire Crystal glass | Polymer middle frame; Stainless steel bezel (316L) |
Display Type | Super AMOLED; Always-On Display; Peak brightness 3000 nits | AMOLED; Gorilla Glass; Peak brightness 2000 nits |
Display Size | 1.5 in (37.3 mm) circular display | 1.5 in (38.1 mm) diameter |
Resolution | 480 x 480 pixels | 480 x 480 pixels (322 ppi) |
Always On Display | Yes | Yes |
Water Resistance | 10 ATM + IP68 (ISO 22810 standard); Ocean swimming capable | 10 ATM (100 meters); Freediving certified (EN13319) to 45m |
Durability | MIL-STD-810H certified; Operating temp -20°C to 55°C; 9000m altitude resistance | MIL-STD-810H (70°C heat / -30°C cold / Shock / Humidity); Mud-resistant bridge and buttons |
GPS | Dual-frequency GPS (L1+L5); Glonass; Beidou; Galileo | Dual-band GNSS (L1+L5); 6 Satellite Positioning Systems (GPS, GLONASS, Galileo, BeiDou, QZSS, NAVIC) |
Connectivity | LTE (eSIM standard on all models); Wi-Fi 2.4+5GHz; Bluetooth 5.3; NFC | Wi-Fi (2.4GHz); Bluetooth 5.2; BLE |
NFC Payments | Samsung Wallet / Google Wallet | Zepp Pay (Europe/parts of Asia only); Not supported on US models |
Sensors | Samsung BioActive Sensor (Optical Bio-signal + Electrical Heart + Bioelectrical Impedance Analysis); Temperature sensor; Accelerometer; Barometer; Gyro sensor; Geomagnetic sensor; Light sensor | BioTracker™ 6.0 PPG biometric sensor (SpO2, Heart Rate); Accelerometer; Gyroscope; Geomagnetic sensor; Barometric altimeter; Ambient light sensor; Temperature sensor (skin/water) |
Health Features | Energy Score; Sleep Apnea detection (FDA authorized); AGEs Index; Body Composition; ECG; Irregular Heart Rhythm Notification; Cycle Tracking with skin temperature; Sleep coaching | 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 | Multisport tile (Triathlon/Duathlon/Aquathlon); Functional Threshold Power (FTP) for cycling; Race Partner; Track Back; Custom workouts via Quick Button | 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 | Speaker (with Siren support); Microphone | Microphone (for Zepp Flow voice commands); No Speaker (Buzzer/Beeper only for alerts) |
Calls | Yes (LTE standalone or via paired phone) | No (Cannot answer calls on wrist; can reject/ignore calls) |
Battery | 590mAh; Up to 100 hours (Power Saving); Up to 60 hours (Normal use, AOD off); Up to 48 hours (Exercise Power Saving) | 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 | Fast Wireless Charging (WPC Inductive); Proprietary puck required for max speed | Magnetic charging base (2-pin); Approx. 3 hours to full charge |
Weight | 60.5 g (Body only) | 68.3 g (without strap) |
Band Sizes | One Size (fits 145–205mm wrists via Dynamic Lug System) | 22mm width; Fits 145–210mm wrists (Proprietary screws but includes adapters for standard bands in some regions) |
Extras | Quick Button (customizable); 86dB Emergency Siren; Night Mode watch face; Gesture controls (Double Pinch) | Offline Maps (Contour/Terrain); Turn-by-turn navigation; Zepp Flow (AI voice assistant); Night Display mode; Glove mode |
| Pros |
|
|
| Cons |
|
|
As an Amazon Associate I earn from qualifying purchases. | Check Price on Amazon→ | Check Price on Amazon→ |
Samsung Galaxy Watch Ultra
Rating:★4.4(243)Amazon
Compatibility:Android 11.0 or higher with 1.5GB+ RAM; Samsung Galaxy phone required for Energy Score, ECG, Sleep Apnea, and IHRN features
Operating System:Wear OS 5 powered by Samsung (One UI 6 Watch)
Case Size:47.4mm H x 47.1mm W x 12.1mm D
Case Material:Titanium (Grade 4) frame with cushion design; Sapphire Crystal glass
Display Type:Super AMOLED; Always-On Display; Peak brightness 3000 nits
Display Size:1.5 in (37.3 mm) circular display
Resolution:480 x 480 pixels
Always On Display:Yes
Water Resistance:10 ATM + IP68 (ISO 22810 standard); Ocean swimming capable
Durability:MIL-STD-810H certified; Operating temp -20°C to 55°C; 9000m altitude resistance
GPS:Dual-frequency GPS (L1+L5); Glonass; Beidou; Galileo
Connectivity:LTE (eSIM standard on all models); Wi-Fi 2.4+5GHz; Bluetooth 5.3; NFC
NFC Payments:Samsung Wallet / Google Wallet
Sensors:Samsung BioActive Sensor (Optical Bio-signal + Electrical Heart + Bioelectrical Impedance Analysis); Temperature sensor; Accelerometer; Barometer; Gyro sensor; Geomagnetic sensor; Light sensor
Health Features:Energy Score; Sleep Apnea detection (FDA authorized); AGEs Index; Body Composition; ECG; Irregular Heart Rhythm Notification; Cycle Tracking with skin temperature; Sleep coaching
Workout Modes:Multisport tile (Triathlon/Duathlon/Aquathlon); Functional Threshold Power (FTP) for cycling; Race Partner; Track Back; Custom workouts via Quick Button
Storage:32GB
Speaker Mic:Speaker (with Siren support); Microphone
Calls:Yes (LTE standalone or via paired phone)
Battery:590mAh; Up to 100 hours (Power Saving); Up to 60 hours (Normal use, AOD off); Up to 48 hours (Exercise Power Saving)
Charging:Fast Wireless Charging (WPC Inductive); Proprietary puck required for max speed
Weight:60.5 g (Body only)
Band Sizes:One Size (fits 145–205mm wrists via Dynamic Lug System)
Extras:Quick Button (customizable); 86dB Emergency Siren; Night Mode watch face; Gesture controls (Double Pinch)
✓ Pros:
- • True multi-day battery life (up to 100h in power saving)
- • Extremely durable Grade 4 Titanium build with 10ATM rating
- • Dual-frequency GPS (L1+L5) provides superior tracking accuracy
- • Brightest display in class (3000 nits) for outdoor visibility
- • Exclusive features like Siren and Multisport tile for triathletes
✗ Cons:
- • Large 47mm square-circle design may not fit smaller wrists
- • Key health features (ECG, Sleep Apnea) locked to Samsung phones
- • Proprietary band attachment (Dynamic Lug) limits third-party options
- • Charging speed is slower (~2 hours) compared to competitors
As an Amazon Associate I earn from qualifying purchases.
Check Price on Amazon→
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.
Check Price on Amazon→
Which one is better?
The Samsung Galaxy Watch Ultra is the better buy for most people - its 100 hours of battery life crushes the Amazfit T-Rex 3's 27 days. That said, grab the T-Rex 3 if you want to save money and don't need LTE connectivity.
Who should buy each?
Choose the Samsung Galaxy Watch Ultra if: you want the longest battery life in Power Saving mode, a top-tier display for outdoor visibility, or need advanced health features like ECG. (2.13 oz weight)
Choose the Amazfit T-Rex 3 if: you want a rugged watch for outdoor adventures, prefer a longer battery life in standard usage, or are looking for a budget-friendly option. (2.41 oz weight)
Conclusion
We hope this comparison helps you buy with confidence. Both products are dependable; the right one depends on how you will use it.
Frequently Asked Questions
+Which has better value?
Samsung Galaxy Watch Ultra excels if you value true multi-day battery life (up to 100h in power saving). 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.
Affiliate disclosure
PageBen uses Amazon affiliate links. If you purchase through our links, we may earn a commission at no extra cost to you. This supports independent content for US shoppers.