Between the T-Rex 3 and Watch SE 3, the T-Rex 3 comes out ahead in battery life and peak brightness, while the Watch SE 3 wins on weight and display size. Overall, the T-Rex 3 scores 79.7 and the Watch SE 3 scores 56.1 on our Mars Score.
Which should you buy?
The T-Rex 3 is the clear pick on raw spec strength, leading by 23.6 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
Pick the T-Rex 3 if your top frustration with your current device is running out of charge before the day ends — endurance is the lead spec here. The biggest gaps in its favor are battery life, peak brightness, water resistance, among others.
Pick the Watch SE 3 if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are weight, display size, cellular.
Both ship with comparable ecg, so those specs don't separate the two — focus on the differences below.
Bottom line: the T-Rex 3 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Amazfit - T-Rex 3 wins
- ▲Battery life — 3633.33% more. 672 h vs 18 h.
- ▲Peak brightness — 100.00% more. 2000 nits vs 1000 nits.
- ▲Water resistance — 5.00 ATM more. 10 vs 5.
- ▲Has SpO2.
Why Apple - Watch SE 3 wins
- ▲Weight — 35.00 g less. 33 vs 68.
- ▲Display size — 18.67% more. 1.78 " vs 1.5 ".
- ▲Has Cellular.
Spec comparison
Design
| Spec | Amazfit - T-Rex 3 | Apple - Watch SE 3 |
|---|---|---|
| Case size | 48.5 mmlead | 44 mm |
| Weight | 68 g | 33 glead |
| Case material | polymer | aluminum |
| Water resistanceⓘ | 10 ATMlead | 5 ATM |
Display
| Spec | Amazfit - T-Rex 3 | Apple - Watch SE 3 |
|---|---|---|
| Display size | 1.5 " | 1.78 "lead |
| Always-on display | truelead | false |
| Peak brightnessⓘ | 2000 nitslead | 1000 nits |
Health & Fitness
| Spec | Amazfit - T-Rex 3 | Apple - Watch SE 3 |
|---|---|---|
| ECG | false | false |
| SpO2 | truelead | false |
| Temperature sensor | truelead | false |
| Sleep tracking | true | true |
| Blood pressure | false | false |
Battery & Connectivity
| Spec | Amazfit - T-Rex 3 | Apple - Watch SE 3 |
|---|---|---|
| Battery life | 672 hlead | 18 h |
| GPS | true | true |
| Cellular | false | truelead |
| NFC | false | truelead |
| OS | Zepp OSlead | watchOS |
Frequently asked
Which has longer battery life, T-Rex 3 or Watch SE 3?+
T-Rex 3 lasts 672h vs 18h.
Do T-Rex 3 or Watch SE 3 support ECG?+
Neither supports ECG.
Which has cellular, T-Rex 3 or Watch SE 3?+
Watch SE 3 offers a cellular variant; T-Rex 3 is Wi-Fi only.
Spec-level deep dives
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