Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Garmin - Fenix 8 (47mm) | Withings - ScanWatch 2 |
|---|---|---|
| Display size | 1.4 " | 0.63 " |
| Battery life | 384 h | 720 h |
| Weight | 73 g | 59 g |
| Water resistance | 10 ATM | 5 ATM |
| Peak brightness | 1000 nits | 0 nits |
Between the Fenix 8 (47mm) and ScanWatch 2, the Fenix 8 (47mm) comes out ahead in display size / water resistance, while the ScanWatch 2 wins on battery life / weight. Overall, the Fenix 8 (47mm) 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 Fenix 8 (47mm) 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, water resistance, peak brightness. The single most decisive one: Display size — 122.22% more. 1.4 " 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 — 87.50% more. 720 h vs 384 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: Garmin - Fenix 8 (47mm) 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 Garmin - Fenix 8 (47mm) if…
Garmin - Fenix 8 (47mm) has the measurable edge on display size in, water resistance atm, peak brightness nits.
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 Garmin - Fenix 8 (47mm) wins
- ▲Display size — 122.22% more. 1.4 " vs 0.63 ".
- ▲Water resistance — 5.00 ATM more. 10 vs 5.
- ▲Peak brightness: 1000 nits vs 0 nits.
Why Withings - ScanWatch 2 wins
- ▲Battery life — 87.50% more. 720 h vs 384 h.
- ▲Weight — 14.00 g less. 59 vs 73.
Spec comparison
Design
| Spec | Garmin - Fenix 8 (47mm) | Withings - ScanWatch 2 |
|---|---|---|
| Case size | 47 mmlead | 42 mm |
| Weight | 73 g | 59 glead |
| Case material | fiber-reinforced polymer | stainless steel |
| Water resistanceⓘ | 10 ATMlead | 5 ATM |
Display
| Spec | Garmin - Fenix 8 (47mm) | Withings - ScanWatch 2 |
|---|---|---|
| Display size | 1.4 "lead | 0.63 " |
| Always-on display | truelead | false |
| Peak brightnessⓘ | 1000 nitslead | 0 nits |
Health & Fitness
| Spec | Garmin - Fenix 8 (47mm) | Withings - ScanWatch 2 |
|---|---|---|
| ECG | true | true |
| SpO2 | true | true |
| Temperature sensor | true | true |
| Sleep tracking | true | true |
| Blood pressure | false | false |
Battery & Connectivity
| Spec | Garmin - Fenix 8 (47mm) | Withings - ScanWatch 2 |
|---|---|---|
| Battery lifeⓘ | 384 h | 720 hlead |
| GPS | truelead | false |
| Cellular | false | false |
| NFC | truelead | false |
| OS | Garmin OS | Withings OSlead |
Frequently asked
Which has longer battery life, Fenix 8 (47mm) or ScanWatch 2?+
ScanWatch 2 lasts 720 hours vs 384 hours.
Do Fenix 8 (47mm) or ScanWatch 2 support ECG?+
Both support ECG.
Which has cellular, Fenix 8 (47mm) or ScanWatch 2?+
Neither offers cellular.