Polar M400 vs. Fitbit Alta HR vs. Garmin Vivofit 4 vs. Amazfit T-Rex
 | | | | |
| PolarM400Remove Buy Now | FitbitAlta HRRemove Buy Now | GarminVivofit 4Remove Buy Now | AmazfitT-RexRemove Buy Now |
Basic Info | ||||
| Suggested Price | $200 | $150 | $79.95 | $140 |
| Release | 2014 | 2017 | 2018 | 2019 |
Activity & Fitness | ||||
| Calories | ||||
| Cycling (Bicycling) | ||||
| Distance | ||||
| Heart | n/a | |||
| Oxygen | ||||
| Sleep | ||||
| Steps | ||||
| Swim | ||||
Battery | ||||
| Duration | 8 hours to 30 days | 7 days | 1 year | 20 days |
| Rechargeable | ||||
Compatibility | ||||
| Android | ||||
| iOS | ||||
| Windows Phone | n/a | |||
| Mac | ||||
| Windows | ||||
Connectivity | ||||
| Bluetooth | ||||
| Cellular | ||||
| GPS | ||||
| NFC | ||||
| Wi-Fi | ||||
Display | ||||
| Color | ||||
| Resolution | n/a | 128 x 36 | 88 x 88 | 360 x 360 |
| Size | n/a | 1.4 inches | NA | 1.3 inches |
| Touch | ||||
| Type | n/a | OLED | NA | AMOLED |
Functions | ||||
| Audio Speaker | Alerts only | |||
| Clock | ||||
| Phone | ||||
| Vibration | ||||
| Voice | ||||
Hardware | ||||
| Accelerometer | ||||
| Barometer or Altimeter | ||||
| Ultraviolet Sensor | ||||
| Water Resistance | 3 ATM | 5 ATM | 5 ATM | |
Notifications | ||||
| Phone | ||||
| Emails | ||||
| Texts | ||||
Software | ||||
| Operating System | n/a | Build-in | ||
| Apps | ||||
| Music | ||||