Polar M400 vs. Casio WSD-F20A vs. Jawbone UP4 vs. Amazfit T-Rex
 | | | | |
| PolarM400Remove Buy Now | CasioWSD-F20ARemove Buy Now | JawboneUP4Remove Buy Now | AmazfitT-RexRemove Buy Now |
Basic Info | |||||
| Suggested Price | $200 | $399 | $200 | $140 | |
| Release | 2014 | 2018 | 2015 | 2019 | |
Activity & Fitness | |||||
| Calories | |||||
| Cycling (Bicycling) | |||||
| Distance | |||||
| Heart | n/a | ||||
| Oxygen | |||||
| Sleep | |||||
| Steps | |||||
| Swim | |||||
Battery | |||||
| Duration | 8 hours to 30 days | 1 day | NA | 20 days | |
| Rechargeable | |||||
Compatibility | |||||
| Android | |||||
| iOS | |||||
| Windows Phone | n/a | NA | |||
| Mac | NA | ||||
| Windows | NA | ||||
Connectivity | |||||
| Bluetooth | |||||
| Cellular | |||||
| GPS | |||||
| NFC | |||||
| Wi-Fi | |||||
Display | |||||
| Color | |||||
| Resolution | n/a | 320 x 320 | NA | 360 x 360 | |
| Size | n/a | 1.32 inches | NA | 1.3 inches | |
| Touch | NA | ||||
| Type | n/a | LCD | NA | AMOLED | |
Functions | |||||
| Audio Speaker | Alerts only | ||||
| Clock | |||||
| Phone | |||||
| Vibration | |||||
| Voice | |||||
Hardware | |||||
| Accelerometer | |||||
| Barometer or Altimeter | |||||
| Ultraviolet Sensor | |||||
| Water Resistance | 3 ATM | 5 ATM | NA | 5 ATM | |
Notifications | |||||
| Phone | |||||
| Emails | |||||
| Texts | |||||
Software | |||||
| Operating System | n/a | Wear OS | NA | Build-in | |
| Apps | |||||
| Music | NA | ||||