Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Apple - Watch Ultra 2 | Withings - ScanWatch 2 |
|---|---|---|
| Battery life | 36 h | 720 h |
| Display size | 1.92 " | 0.63 " |
| Water resistance | 10 ATM | 5 ATM |
| Weight | 61.4 g | 59 g |
| Cellular | true | false |
| Peak brightness | 3000 nits | 0 nits |
Between the Watch Ultra 2 and ScanWatch 2, the Watch Ultra 2 comes out ahead in display size / water resistance, while the ScanWatch 2 wins on battery life / weight. Overall, the Watch Ultra 2 scores 71.9 and the ScanWatch 2 scores 78.3 on our Mars Score.
Which should you buy?
The ScanWatch 2 edges ahead on the Mars Score (71.9 vs 78.3), but the 6.4-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the Watch Ultra 2 if you care most about display size / water resistance. The biggest gaps in its favor are display size, water resistance, cellular, among others. The single most decisive one: Display size — 204.76% more. 1.92 " 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, weight. The single most decisive one: Battery life — 1900.00% more. 720 h vs 36 h.
Both ship with comparable ecg, 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: Apple - Watch Ultra 2 or Withings - ScanWatch 2?
Withings - ScanWatch 2 leads the current Mars Score by 6.4 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 Ultra 2 if…
Apple - Watch Ultra 2 has the measurable edge on display size in, water resistance atm, has cellular.
Choose Withings - ScanWatch 2 if…
Withings - ScanWatch 2 has the measurable edge on battery life h, weight g.
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 Ultra 2 wins
- ▲Display size — 204.76% more. 1.92 " vs 0.63 ".
- ▲Water resistance — 5.00 ATM more. 10 vs 5.
- ▲Has Cellular.
- ▲Peak brightness: 3000 nits vs 0 nits.
Why Withings - ScanWatch 2 wins
- ▲Battery life — 1900.00% more. 720 h vs 36 h.
- ▲Weight — 2.40 g less. 59 vs 61.4.
Spec comparison
Design
| Spec | Apple - Watch Ultra 2 | Withings - ScanWatch 2 |
|---|---|---|
| Case size | 49 mmlead | 42 mm |
| Weight | 61.4 g | 59 glead |
| Case material | titanium | stainless steel |
| Water resistanceⓘ | 10 ATMlead | 5 ATM |
Display
| Spec | Apple - Watch Ultra 2 | Withings - ScanWatch 2 |
|---|---|---|
| Display size | 1.92 "lead | 0.63 " |
| Always-on display | truelead | false |
| Peak brightnessⓘ | 3000 nitslead | 0 nits |
Health & Fitness
| Spec | Apple - Watch Ultra 2 | Withings - ScanWatch 2 |
|---|---|---|
| ECG | true | true |
| SpO2 | true | true |
| Temperature sensor | true | true |
| Sleep tracking | true | true |
| Blood pressure | false | false |
Battery & Connectivity
| Spec | Apple - Watch Ultra 2 | Withings - ScanWatch 2 |
|---|---|---|
| Battery lifeⓘ | 36 h | 720 hlead |
| GPS | truelead | false |
| Cellular | truelead | false |
| NFC | truelead | false |
| OS | watchOS | Withings OSlead |
Frequently asked
Which has longer battery life, Watch Ultra 2 or ScanWatch 2?+
ScanWatch 2 lasts 720 hours vs 36 hours.
Do Watch Ultra 2 or ScanWatch 2 support ECG?+
Both support ECG.
Which has cellular, Watch Ultra 2 or ScanWatch 2?+
Watch Ultra 2 offers a cellular variant; ScanWatch 2 is Wi-Fi only.