Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch Ultra 2 |
|---|---|---|
| Battery life | 18 h | 60 h |
| Peak brightness | 1000 nits | 3000 nits |
| Weight | 33 g | 60 g |
| Display size | 1.78 " | 1.5 " |
| Water resistance | 5 ATM | 10 ATM |
| ECG | false | true |
Between the Watch SE 3 and Galaxy Watch Ultra 2, the Watch SE 3 comes out ahead in weight / display size, while the Galaxy Watch Ultra 2 wins on battery life / peak brightness. Overall, the Watch SE 3 scores 55.9 and the Galaxy Watch Ultra 2 scores 67.5 on our Mars Score.
Which should you buy?
The Galaxy Watch Ultra 2 is the clear pick on raw spec strength, leading by 11.6 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 weight, display size. The single most decisive one: Weight — 27.00 g less. 33 vs 60.
Pick the Galaxy Watch Ultra 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, peak brightness, water resistance, among others. The single most decisive one: Battery life — 233.33% more. 60 h vs 18 h.
Both ship with comparable cellular, so those specs do not separate the two — focus on the differences below.
Bottom line: the Galaxy Watch Ultra 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 Samsung - Galaxy Watch Ultra 2?
Samsung - Galaxy Watch Ultra 2 leads the current Mars Score by 11.6 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 weight g, display size in.
Choose Samsung - Galaxy Watch Ultra 2 if…
Samsung - Galaxy Watch Ultra 2 has the measurable edge on battery life h, peak brightness nits, water resistance atm.
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
- ▲Weight — 27.00 g less. 33 vs 60.
- ▲Display size — 18.67% more. 1.78 " vs 1.5 ".
Why Samsung - Galaxy Watch Ultra 2 wins
- ▲Battery life — 233.33% more. 60 h vs 18 h.
- ▲Peak brightness — 200.00% more. 3000 nits vs 1000 nits.
- ▲Water resistance — 5.00 ATM more. 10 vs 5.
- ▲Has ECG.
- ▲Has SpO2.
Spec comparison
Design
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch Ultra 2 |
|---|---|---|
| Case size | 44 mm | 47 mmlead |
| Weight | 33 glead | 60 g |
| Case material | aluminum | titanium |
| Water resistanceⓘ | 5 ATM | 10 ATMlead |
Display
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch Ultra 2 |
|---|---|---|
| Display size | 1.78 "lead | 1.5 " |
| Always-on display | true | true |
| Peak brightnessⓘ | 1000 nits | 3000 nitslead |
Health & Fitness
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch Ultra 2 |
|---|---|---|
| ECG | false | truelead |
| SpO2 | false | truelead |
| Temperature sensor | true | true |
| Sleep tracking | true | true |
| Blood pressure | false | truelead |
Battery & Connectivity
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch Ultra 2 |
|---|---|---|
| Battery lifeⓘ | 18 h | 60 hlead |
| GPS | true | true |
| Cellular | true | true |
| NFC | true | true |
| OS | watchOS | WearOSlead |
Frequently asked
Which has longer battery life, Watch SE 3 or Galaxy Watch Ultra 2?+
Galaxy Watch Ultra 2 lasts 60 hours vs 18 hours.
Do Watch SE 3 or Galaxy Watch Ultra 2 support ECG?+
Galaxy Watch Ultra 2 supports ECG; Watch SE 3 does not.
Which has cellular, Watch SE 3 or Galaxy Watch Ultra 2?+
Both offer cellular variants.