Apple Watch Ultra (1st Gen) vs Garmin Forerunner 255
The Verdict
Apple Watch Ultra dominates in display quality with its vibrant LTPO OLED Retina screen versus Garmin's basic MIP transflective display, and offers superior health monitoring including ECG and skin temperature sensors. Performance and software are notably more advanced on watchOS 11+, supporting broader app ecosystems and seamless iPhone integration. Battery life differs significantly: Apple delivers 36 hours normal or 60 hours in Low Power Mode, while Garmin achieves 14 days smartwatch mode but only 30 hours with continuous GPS. Garmin excels for dedicated runners and athletes with sport-specific features and exceptional battery longevity. Build quality favors Apple's titanium construction over Garmin's polymer casing, though Garmin is considerably lighter at 49g. For general users prioritizing technology and features, Apple Watch Ultra is superior. For endurance athletes and ultramarathoners needing multi-week battery life, Garmin Forerunner 255 remains the practical choice.
Who Should Buy
Buy the Apple Watch Ultra (1st Gen) if…
- →Titanium case is exceptionally durable for extreme sports and diving
- →36-hour battery life (60 hrs in Low Power Mode) is longest for Apple Watch
- →2000-nit peak brightness is readable in any outdoor condition
Buy the Garmin Forerunner 255 if…
- →14-day battery life means weekly charging at most
- →Multi-band GPS for exceptional outdoor tracking accuracy
- →Morning Report with daily training readiness and HRV status
Category Scores
Pros & Cons
Apple Watch Ultra (1st Gen)
Pros
- Titanium case is exceptionally durable for extreme sports and diving
- 36-hour battery life (60 hrs in Low Power Mode) is longest for Apple Watch
- 2000-nit peak brightness is readable in any outdoor condition
- Dual-frequency L1+L5 GPS provides precise tracking even in canyons
- Action Button is customizable for workouts, compass, and more
Cons
- 49mm case is very large — may be too bulky for smaller wrists
- Heavy at 61.3 g compared to standard Apple Watch models
- $799 is expensive for a first-generation product
- S8 chip is the same as Series 8 — no processing advantage
- Only one 49mm size option with no smaller variant
Garmin Forerunner 255
Pros
- 14-day battery life means weekly charging at most
- Multi-band GPS for exceptional outdoor tracking accuracy
- Morning Report with daily training readiness and HRV status
- Race Predictor estimates finish times for 5K to marathon
- Lightweight at 49 g and comfortable for 24/7 wear
Cons
- MIP display lacks the vibrancy of AMOLED competitors
- No touchscreen on base model — button-only navigation
- No ECG or blood pressure monitoring
- Limited smart features compared to Apple Watch or Wear OS
- Third-party app ecosystem is small
Full Specifications
| Spec | Apple Watch Ultra (1st Gen) | Garmin Forerunner 255 |
|---|---|---|
| Software | watchOS 9 (upgradable to watchOS 11+) | Garmin proprietary OS |
| Body | ||
| Weight | 61.3 g | 49 g |
| Case material | Titanium | Fiber-reinforced polymer |
| Water resistance | WR100, EN13319 (certified for recreational scuba diving to 40m) | 5ATM |
| Health & Sensors | ||
| ECG | ||
| SpO₂ | ||
| Skin temperature | ||
| Heart rate | ||
| Sleep tracking | ||
| Battery | ||
| Battery life | Up to 36 hours (60 hrs in Low Power Mode) | Up to 14 days (smartwatch), 30 hrs GPS |
| Display | ||
| Size | 49mm | 46mm |
| Type | LTPO OLED Always-On Retina | MIP (Memory-in-Pixel) transflective |
| Always-on display | ||
| Resolution | 410 x 502 | 260 x 260 |
| Processor | ||
| Chipset | Apple S8 SiP | Garmin custom SoC |
| Connectivity | ||
| GPS | ||
| NFC | ||
| Wi-Fi | ||
| Cellular | ||
| Bluetooth | 5.3 | 5.0 |
Related Comparisons
This comparison is based on verified manufacturer specifications covering display, performance, camera, battery, and build quality. Scores are generated by analyzing specs across weighted categories on a 10-point scale. Learn more about our methodology.
Explore more in smartwatches, see all Apple products or all Garmin products. View full details for the Apple Watch Ultra (1st Gen) or the Garmin Forerunner 255.