Polar M400 vs. Fitbit Flex vs. Jawbone UP4 vs. Amazfit GTR
Basic Info |
| Suggested Price | $200 | $100 | $200 | $199 |
| Release | 2014 | 2013 | 2015 | 2019 |
Activity & Fitness |
| Calories | | | | |
| Cycling (Bicycling) | | | | |
| Distance | | | | |
| Heart | n/a | | | |
| Oxygen | | | | |
| Sleep | | | | |
| Steps | | | | |
| Swim | | | | |
Battery |
| Duration | 8 hours to 30 days | 5 days | NA | 24 days |
| Rechargeable | | | | |
Compatibility |
| Android | | | | |
| iOS | | | | |
| Windows Phone | n/a | NA | NA | |
| Mac | | | NA | |
| Windows | | | NA | |
Connectivity |
| Bluetooth | | | | |
| Cellular | | | | |
| GPS | | | | |
| NFC | | | | |
| Wi-Fi | | | | |
Display |
| Color | | | | |
| Resolution | n/a | NA | NA | 454 x 454 |
| Size | n/a | NA | NA | 1.39 inches |
| Touch | | NA | NA | |
| Type | n/a | LED | NA | AMOLED |
Functions |
| Audio Speaker | Alerts only | | | |
| Clock | | | | |
| Phone | | | | |
| Vibration | | | | |
| Voice | | | | |
Hardware |
| Accelerometer | | | | |
| Barometer or Altimeter | | | | |
| Ultraviolet Sensor | | | | |
| Water Resistance | 3 ATM | 1 ATM | NA | 5 ATM |
Notifications |
| Phone | | | | |
| Emails | | | | |
| Texts | | | | |
Software |
| Operating System | n/a | NA | NA | Build-in |
| Apps | | | | |
| Music | | | NA | |
