Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Apple - Watch SE 3 | Withings - ScanWatch 2 |
|---|---|---|
| Battery life | 18 h | 720 h |
| Display size | 1.78 " | 0.63 " |
| Weight | 33 g | 59 g |
| Cellular | true | false |
| ECG | false | true |
| SpO2 | false | true |
Between the Watch SE 3 and ScanWatch 2, the Watch SE 3 comes out ahead in display size / weight, while the ScanWatch 2 wins on battery life / ecg. Overall, the Watch SE 3 scores 55.9 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 22.4 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 Watch SE 3 if you carry the device everywhere and weight or thickness has been the deciding factor before. The biggest gaps in its favor are display size, weight, cellular, among others. The single most decisive one: Display size — 182.54% more. 1.78 " 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, ecg, spo2. The single most decisive one: Battery life — 3900.00% more. 720 h vs 18 h.
Both ship with comparable water resistance, 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: Apple - Watch SE 3 or Withings - ScanWatch 2?
Withings - ScanWatch 2 leads the current Mars Score by 22.4 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 Apple - Watch SE 3 if…
Apple - Watch SE 3 has the measurable edge on display size in, weight g, has cellular.
Choose Withings - ScanWatch 2 if…
Withings - ScanWatch 2 has the measurable edge on battery life h, has ecg, has spo2.
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 Apple - Watch SE 3 wins
- ▲Display size — 182.54% more. 1.78 " vs 0.63 ".
- ▲Weight — 26.00 g less. 33 vs 59.
- ▲Has Cellular.
- ▲Peak brightness: 1000 nits vs 0 nits.
Why Withings - ScanWatch 2 wins
- ▲Battery life — 3900.00% more. 720 h vs 18 h.
- ▲Has ECG.
- ▲Has SpO2.
Spec comparison
Design
| Spec | Apple - Watch SE 3 | Withings - ScanWatch 2 |
|---|---|---|
| Case size | 44 mmlead | 42 mm |
| Weight | 33 glead | 59 g |
| Case material | aluminum | stainless steel |
| Water resistanceⓘ | 5 ATM | 5 ATM |
Display
| Spec | Apple - Watch SE 3 | Withings - ScanWatch 2 |
|---|---|---|
| Display size | 1.78 "lead | 0.63 " |
| Always-on display | truelead | false |
| Peak brightnessⓘ | 1000 nitslead | 0 nits |
Health & Fitness
| Spec | Apple - Watch SE 3 | Withings - ScanWatch 2 |
|---|---|---|
| ECG | false | truelead |
| SpO2 | false | truelead |
| Temperature sensor | true | true |
| Sleep tracking | true | true |
| Blood pressure | false | false |
Battery & Connectivity
| Spec | Apple - Watch SE 3 | Withings - ScanWatch 2 |
|---|---|---|
| Battery lifeⓘ | 18 h | 720 hlead |
| GPS | truelead | false |
| Cellular | truelead | false |
| NFC | truelead | false |
| OS | watchOS | Withings OSlead |
Frequently asked
Which has longer battery life, Watch SE 3 or ScanWatch 2?+
ScanWatch 2 lasts 720 hours vs 18 hours.
Do Watch SE 3 or ScanWatch 2 support ECG?+
ScanWatch 2 supports ECG; Watch SE 3 does not.
Which has cellular, Watch SE 3 or ScanWatch 2?+
Watch SE 3 offers a cellular variant; ScanWatch 2 is Wi-Fi only.