Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Polar - Vantage V3 | Withings - ScanWatch 2 |
|---|---|---|
| Battery life | 168 h | 720 h |
| Display size | 1.39 " | 0.63 " |
| Weight | 57 g | 59 g |
| Peak brightness | 1000 nits | 0 nits |
Between the Vantage V3 and ScanWatch 2, the Vantage V3 comes out ahead in display size / weight, while the ScanWatch 2 wins on battery life. Overall, the Vantage V3 scores 69.2 and the ScanWatch 2 scores 78.3 on our Mars Score.
Which should you buy?
The ScanWatch 2 is the clear pick on raw spec strength, leading by 9.1 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 Vantage V3 if the display is what you stare at all day — refresh rate, brightness, or sharpness is where the difference will be most visible. The biggest gaps in its favor are display size, weight, peak brightness. The single most decisive one: Display size — 120.63% more. 1.39 " vs 0.63 ".
Pick the ScanWatch 2 if your top frustration with your current device is running out of charge before the day ends — endurance is the lead spec here. Its strongest claims are battery life. The single most decisive one: Battery life — 328.57% more. 720 h vs 168 h.
Both ship with comparable ecg, cellular, spo2, so those specs do not separate the two — focus on the differences below.
Bottom line: the ScanWatch 2 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: Polar - Vantage V3 or Withings - ScanWatch 2?
Withings - ScanWatch 2 leads the current Mars Score by 9.1 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 Polar - Vantage V3 if…
Polar - Vantage V3 has the measurable edge on display size in, weight g, peak brightness nits.
Choose Withings - ScanWatch 2 if…
Withings - ScanWatch 2 has the measurable edge on battery life h.
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 Polar - Vantage V3 wins
- ▲Display size — 120.63% more. 1.39 " vs 0.63 ".
- ▲Weight — 2.00 g less. 57 vs 59.
- ▲Peak brightness: 1000 nits vs 0 nits.
Why Withings - ScanWatch 2 wins
- ▲Battery life — 328.57% more. 720 h vs 168 h.
Spec comparison
Design
| Spec | Polar - Vantage V3 | Withings - ScanWatch 2 |
|---|---|---|
| Case size | 47 mmlead | 42 mm |
| Weight | 57 glead | 59 g |
| Case material | aluminum | stainless steel |
| Water resistanceⓘ | 5 ATM | 5 ATM |
Display
| Spec | Polar - Vantage V3 | Withings - ScanWatch 2 |
|---|---|---|
| Display size | 1.39 "lead | 0.63 " |
| Always-on display | truelead | false |
| Peak brightnessⓘ | 1000 nitslead | 0 nits |
Health & Fitness
| Spec | Polar - Vantage V3 | Withings - ScanWatch 2 |
|---|---|---|
| ECG | true | true |
| SpO2 | true | true |
| Temperature sensor | true | true |
| Sleep tracking | true | true |
| Blood pressure | false | false |
Battery & Connectivity
| Spec | Polar - Vantage V3 | Withings - ScanWatch 2 |
|---|---|---|
| Battery lifeⓘ | 168 h | 720 hlead |
| GPS | truelead | false |
| Cellular | false | false |
| NFC | false | false |
| OS | Polar OS | Withings OSlead |
Frequently asked
Which has longer battery life, Vantage V3 or ScanWatch 2?+
ScanWatch 2 lasts 720 hours vs 168 hours.
Do Vantage V3 or ScanWatch 2 support ECG?+
Both support ECG.
Which has cellular, Vantage V3 or ScanWatch 2?+
Neither offers cellular.