Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Amazfit - T-Rex 3 | Polar - Vantage V3 |
|---|---|---|
| Battery life | 672 h | 168 h |
| Peak brightness | 2000 nits | 1000 nits |
| Weight | 68 g | 57 g |
| Display size | 1.5 " | 1.39 " |
| Water resistance | 10 ATM | 5 ATM |
| ECG | false | true |
Between the T-Rex 3 and Vantage V3, the T-Rex 3 comes out ahead in battery life / peak brightness, while the Vantage V3 wins on weight / ecg. Overall, the T-Rex 3 scores 62.7 and the Vantage V3 scores 69.2 on our Mars Score.
Which should you buy?
The Vantage V3 edges ahead on the Mars Score (62.7 vs 69.2), but the 6.5-point gap is small enough that the right pick comes down to which spec advantages matter to you.
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, display size, among others. The single most decisive one: Battery life — 300.00% more. 672 h vs 168 h.
Pick the Vantage V3 if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are weight, ecg. The single most decisive one: Weight — 11.00 g less. 57 vs 68.
Both ship with comparable cellular, spo2, so those specs do not separate the two — focus on the differences below.
Bottom line: the Vantage V3 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Which should you buy: Amazfit - T-Rex 3 or Polar - Vantage V3?
Polar - Vantage V3 leads the current Mars Score by 6.5 points.The more useful decision is the trade-off behind that result: compare display size, battery life against the way you will actually use the product.
Choose Amazfit - T-Rex 3 if…
Amazfit - T-Rex 3 has the measurable edge on battery life h, peak brightness nits, display size in.
Choose Polar - Vantage V3 if…
Polar - Vantage V3 has the measurable edge on weight g, has ecg.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Amazfit - T-Rex 3 wins
- ▲Battery life — 300.00% more. 672 h vs 168 h.
- ▲Peak brightness — 100.00% more. 2000 nits vs 1000 nits.
- ▲Display size — 7.91% more. 1.5 " vs 1.39 ".
- ▲Water resistance — 5.00 ATM more. 10 vs 5.
Why Polar - Vantage V3 wins
- ▲Weight — 11.00 g less. 57 vs 68.
- ▲Has ECG.
Spec comparison
Design
| Spec | Amazfit - T-Rex 3 | Polar - Vantage V3 |
|---|---|---|
| Case size | 48.5 mmlead | 47 mm |
| Weight | 68 g | 57 glead |
| Case material | polymer | aluminum |
| Water resistanceⓘ | 10 ATMlead | 5 ATM |
Display
| Spec | Amazfit - T-Rex 3 | Polar - Vantage V3 |
|---|---|---|
| Display size | 1.5 "lead | 1.39 " |
| Always-on display | true | true |
| Peak brightnessⓘ | 2000 nitslead | 1000 nits |
Health & Fitness
| Spec | Amazfit - T-Rex 3 | Polar - Vantage V3 |
|---|---|---|
| ECG | false | truelead |
| SpO2 | true | true |
| Temperature sensor | true | true |
| Sleep tracking | true | true |
| Blood pressure | false | false |
Battery & Connectivity
| Spec | Amazfit - T-Rex 3 | Polar - Vantage V3 |
|---|---|---|
| Battery lifeⓘ | 672 hlead | 168 h |
| GPS | true | true |
| Cellular | false | false |
| NFC | false | false |
| OS | Zepp OSlead | Polar OS |
Frequently asked
Which has longer battery life, T-Rex 3 or Vantage V3?+
T-Rex 3 lasts 672 hours vs 168 hours.
Do T-Rex 3 or Vantage V3 support ECG?+
Vantage V3 supports ECG; T-Rex 3 does not.
Which has cellular, T-Rex 3 or Vantage V3?+
Neither offers cellular.