Apple - Watch SE 3 vs Samsung - Galaxy Watch 7 (40mm)
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 7 (40mm) |
|---|---|---|
| Peak brightness | 1000 nits | 3000 nits |
| Battery life | 18 h | 30 h |
| Display size | 1.78 " | 1.31 " |
| Weight | 33 g | 28.8 g |
| ECG | false | true |
| SpO2 | false | true |
Between the Watch SE 3 and Galaxy Watch 7 (40mm), the Watch SE 3 comes out ahead in display size, while the Galaxy Watch 7 (40mm) wins on peak brightness / battery life. Overall, the Watch SE 3 scores 55.9 and the Galaxy Watch 7 (40mm) scores 69.6 on our Mars Score.
Which should you buy?
The Galaxy Watch 7 (40mm) is the clear pick on raw spec strength, leading by 13.7 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 care most about display size. The biggest gaps in its favor are display size. The single most decisive one: Display size — 35.88% more. 1.78 " vs 1.31 ".
Pick the Galaxy Watch 7 (40mm) 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 peak brightness, battery life, weight, among others. The single most decisive one: Peak brightness — 200.00% more. 3000 nits vs 1000 nits.
Both ship with comparable cellular, water resistance, so those specs do not separate the two — focus on the differences below.
Bottom line: the Galaxy Watch 7 (40mm) 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 7 (40mm)?
Samsung - Galaxy Watch 7 (40mm) leads the current Mars Score by 13.7 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.
Choose Samsung - Galaxy Watch 7 (40mm) if…
Samsung - Galaxy Watch 7 (40mm) has the measurable edge on peak brightness nits, 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 SE 3 wins
- ▲Display size — 35.88% more. 1.78 " vs 1.31 ".
Why Samsung - Galaxy Watch 7 (40mm) wins
- ▲Peak brightness — 200.00% more. 3000 nits vs 1000 nits.
- ▲Battery life — 66.67% more. 30 h vs 18 h.
- ▲Weight — 4.20 g less. 28.8 vs 33.
- ▲Has ECG.
- ▲Has SpO2.
Spec comparison
Design
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch 7 (40mm) |
|---|---|---|
| Case size | 44 mmlead | 40 mm |
| Weight | 33 g | 28.8 glead |
| Case material | aluminum | aluminum |
| Water resistanceⓘ | 5 ATM | 5 ATM |
Display
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch 7 (40mm) |
|---|---|---|
| Display size | 1.78 "lead | 1.31 " |
| Always-on display | false | truelead |
| Peak brightnessⓘ | 1000 nits | 3000 nitslead |
Health & Fitness
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch 7 (40mm) |
|---|---|---|
| ECG | false | truelead |
| SpO2 | false | truelead |
| Temperature sensor | false | truelead |
| Sleep tracking | true | true |
| Blood pressure | false | truelead |
Battery & Connectivity
| Spec | Apple - Watch SE 3 | Samsung - Galaxy Watch 7 (40mm) |
|---|---|---|
| Battery lifeⓘ | 18 h | 30 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 7 (40mm)?+
Galaxy Watch 7 (40mm) lasts 30 hours vs 18 hours.
Do Watch SE 3 or Galaxy Watch 7 (40mm) support ECG?+
Galaxy Watch 7 (40mm) supports ECG; Watch SE 3 does not.
Which has cellular, Watch SE 3 or Galaxy Watch 7 (40mm)?+
Both offer cellular variants.