Fitbit Sense vs Garmin Forerunner 255
The Verdict
Fitbit Sense excels with its vibrant AMOLED display, comprehensive health sensors including ECG and skin temperature monitoring, and premium aluminum construction. Garmin Forerunner 255 counters with exceptional battery longevity, delivering up to 14 days in smartwatch mode versus Fitbit's 6+ days, plus superior GPS endurance at 30 hours. Display quality differs markedly: Sense's 336x336 AMOLED is sharper and more colorful, while Forerunner's MIP technology prioritizes battery efficiency over visual appeal. Both offer 5ATM water resistance, GPS, NFC, and sleep tracking. For health-conscious users valuing sensor richness and display quality, Fitbit Sense delivers better daily wear experience. Athletes and outdoor enthusiasts preferring extended battery life and proven GPS reliability will favor the Garmin. Fitbit edges ahead for casual fitness tracking; Garmin suits serious athletes.
Who Should Buy
Buy the Fitbit Sense if…
- →Most comprehensive health sensor suite at launch — EDA, ECG, SpO2, skin temp
- →6+ day battery outlasts Apple Watch and Samsung Galaxy Watch
- →Built-in GPS for phone-free outdoor workouts
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
Fitbit Sense
Pros
- Most comprehensive health sensor suite at launch — EDA, ECG, SpO2, skin temp
- 6+ day battery outlasts Apple Watch and Samsung Galaxy Watch
- Built-in GPS for phone-free outdoor workouts
- Stress management score with EDA sensor is unique
- NFC for Fitbit Pay contactless payments
Cons
- Fitbit OS app ecosystem is very limited compared to watchOS/Wear OS
- Capacitive button is unreliable and frustrating to press
- Many advanced features require Fitbit Premium subscription ($10/mo)
- Google acquisition created uncertainty about Fitbit OS future
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 | Fitbit Sense | Garmin Forerunner 255 |
|---|---|---|
| Software | Fitbit OS | Garmin proprietary OS |
| Body | ||
| Weight | 45.9 g | 49 g |
| Case material | Aluminum | Fiber-reinforced polymer |
| Water resistance | 5ATM | 5ATM |
| Health & Sensors | ||
| ECG | ||
| SpO₂ | ||
| Skin temperature | ||
| Heart rate | ||
| Sleep tracking | ||
| Battery | ||
| Battery life | Up to 6+ days | Up to 14 days (smartwatch), 30 hrs GPS |
| Display | ||
| Size | 40mm (1.58 inches) | 46mm |
| Type | AMOLED | MIP (Memory-in-Pixel) transflective |
| Always-on display | ||
| Resolution | 336 x 336 | 260 x 260 |
| Processor | ||
| Chipset | Fitbit custom processor | Garmin custom SoC |
| Connectivity | ||
| GPS | ||
| NFC | ||
| Wi-Fi | ||
| Cellular | ||
| Bluetooth | 5.0 | 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 Fitbit products or all Garmin products. View full details for the Fitbit Sense or the Garmin Forerunner 255.