vs
9.3Display3.8
7.9Smart features3.9
Why is Watch Ultra 4 better than U3?
- Built-in GPSYes · U3: No
- AMOLED / OLED displayYes · U3: No
- NFC paymentsYes · U3: No
- LTE (cellular)Yes · U3: No
- Battery capacity631 mAh vs 300 mAh2.1×
- eSIMYes · U3: No
- Screen size1.98″ vs 1.83″+8%
- Resolution (width)422 px vs 240 px+76%
- Pixel density326 ppi vs 203 ppi+61%
Why is U3 better than Watch Ultra 4?
U3 has no measurable advantages in this pair.
Specifications
Side by side
| Design & durability | ||
| Case size | 49 mm | — |
| Weight | 63 g | — |
| Thickness | 12 mm | — |
| Height | 49 mm | — |
| Width | 44 mm | — |
| Case material | Titanium | — |
| Sapphire crystal | Yes | — |
| Lens / cover glass | Sapphire crystal | — |
| Water resistance | 10 ATM | — |
| Ingress protection | IP6X | IP68 |
| Water resistance (IPx) | — | IPx8 |
| Water rating (maker) | 100 m | — |
| Military-grade (MIL-STD-810) | Yes | — |
| Colours | Natural, Black | Black, Silver, Pink |
| Display | ||
| Screen size | 1.98″ | 1.83″ |
| Display technology | OLED | LCD |
| Panel | Retina LTPO3 OLED | TFT |
| AMOLED / OLED display | Yes | No |
| Always-on display | Yes | — |
| Touchscreen | Yes | — |
| Resolution (width) | 422 px | 240 px |
| Resolution (height) | 514 px | 284 px |
| Pixel density | 326 ppi | 203 ppi |
| Peak brightness | 3,000 nits | — |
| LTPO display | Yes | — |
| Refresh rate | 60 Hz | 60 Hz |
| Battery | ||
| Battery life (smartwatch mode) | 2.1 days | — |
| Battery life (hours) | 50 h | — |
| Battery capacity | 631 mAh | 300 mAh |
| Battery type | Li-Ion | — |
| Wireless charging | Yes | — |
| Charged in 30 min | 53% | — |
| Health sensors | ||
| Optical heart rate | Yes | Yes |
| Blood oxygen (SpO2) | Yes | — |
| ECG | Yes | — |
| Skin temperature | Yes | — |
| Temperature sensor | Yes | — |
| HRV tracking | Yes | — |
| Sleep tracking | Yes | — |
| Sensors | Accelerometer, gyro, always-on heart rate, barometer, always-on altimeter (-500m to 9000m), compass, SpO2, VO2max, temperature (body), temperature (water) | Accelerometer, heart rate |
| Sports & navigation | ||
| Built-in GPS | Yes | No |
| Dual-band GPS | Yes | — |
| Satellite systems | GLONASS, GALILEO, BDS, QZSS | — |
| Barometric altimeter | Yes | — |
| Compass | Yes | — |
| Multisport / triathlon mode | Yes | — |
| Dive mode | Yes | — |
| Connectivity | ||
| NFC payments | Yes | No |
| LTE (cellular) | Yes | No |
| eSIM | Yes | No |
| Satellite messaging | Yes | — |
| Wi-Fi | Wi-Fi 4 | — |
| Bluetooth | 5.3 | 5.4 |
| Ultra Wideband | Yes | — |
| Smart features | ||
| Calls from the wrist | Yes | — |
| Speaker | Yes | Yes |
| Microphone | Yes | — |
| Voice assistant | Yes | — |
| Music on the watch | Yes | — |
| Storage | 64 GB | — |
| Platform | ||
| Operating system | watchOS 27 | Proprietary OS |
| Platform | watchOS | Proprietary |
| Works with | iOS | — |
| Chipset | Apple S11 | — |
