The internals are identical, so it's purely a question of size. Is the bigger screen worth the extra? That depends on your wrist.
Short answer
Apple Watch SE 3 44 mm - a bigger 368×448 display, easier to read notifications and tap buttons. Apple Watch SE 3 40 mm - lighter (26.3 g), sits better on a slim wrist and cheaper.
Key differences
| Spec | Apple Watch SE 3 40mm GPS | Apple Watch SE 3 44mm GPS |
|---|---|---|
| Display | OLED, 324×394 | OLED, 368×448 |
| Chip | Apple S10 | Apple S10 |
| Memory | 64 GB | 64 GB |
| Battery life | up to 18 h | up to 18 h |
| Connectivity | Bluetooth, Wi-Fi | Bluetooth, Wi-Fi |
| Navigation | GPS, GLONASS, Galileo, QZSS, BeiDou (L1) | GPS, GLONASS, Galileo, QZSS, BeiDou (L1) |
| NFC | yes | yes |
| Sensors | heart rate, barometer, compass, gyroscope, temperature | heart rate, barometer, compass, gyroscope, temperature |
| Protection | 50 m | 50 m |
| OS | watchOS 26 | watchOS 26 |
| Compatibility | iPhone 11 / iPhone SE 2 / iOS 26 | iPhone 11 / iPhone SE 2 / iOS 26 |
| Dimensions, weight | 40×34×10.7 mm, 26.3 g | 44×38×10.7 mm, 32.9 g |
| Price | current prices | current prices |
Specs come from the device pages on Smartphone.ua.
What's the same
Apple S10 chip, 64 GB, up to 18 h, GPS, NFC for Apple Pay, water resistance to 50 m, watchOS 26. Heart rate, barometer, compass and temperature on both.
Display and case
40×34 mm and 324×394 vs 44×38 mm and 368×448. Same 10.7 mm thickness, 26.3 vs 32.9 g.
How to choose
If your wrist is under 15-16 cm, the 40 mm will look neater. For a large wrist and small fonts I'd take the 44 mm.
Verdict: who should buy which
- Bigger screen - Apple Watch SE 3 44 mm.
- Slim wrist and saving money - Apple Watch SE 3 40 mm.
FAQ
Is battery life the same?
Yes, up to 18 h according to Apple.
Does it measure SpO2?
No, the SE 3 doesn't in either size.
Which is cheaper?
The 40 mm.