Polar M400 vs. Garmin 645 Music vs. Fitbit Flex vs. Fitbit Sense 2
 | | | | |
| PolarM400Remove Buy Now | Garmin645 MusicRemove Buy Now | FitbitFlexRemove Buy Now | FitbitSense 2Remove Buy Now |
Basic Info | ||||
| Suggested Price | $200 | $450 | $100 | $300 |
| Release | 2014 | 2018 | 2013 | 2022 |
Activity & Fitness | ||||
| Calories | ||||
| Cycling (Bicycling) | ||||
| Distance | ||||
| Heart | n/a | |||
| Oxygen | ||||
| Sleep | ||||
| Steps | ||||
| Swim | ||||
Battery | ||||
| Duration | 8 hours to 30 days | 7 days | 5 days | 6 days |
| Rechargeable | ||||
Compatibility | ||||
| Android | ||||
| iOS | ||||
| Windows Phone | n/a | NA | ||
| Mac | ||||
| Windows | ||||
Connectivity | ||||
| Bluetooth | ||||
| Cellular | ||||
| GPS | ||||
| NFC | ||||
| Wi-Fi | ||||
Display | ||||
| Color | ||||
| Resolution | n/a | 240 x 240 | NA | 336x336 |
| Size | n/a | 1.2 inches | NA | 1.59 inches |
| Touch | NA | |||
| Type | n/a | MIP | LED | AMOLED |
Functions | ||||
| Audio Speaker | Alerts only | |||
| Clock | ||||
| Phone | ||||
| Vibration | ||||
| Voice | ||||
Hardware | ||||
| Accelerometer | ||||
| Barometer or Altimeter | ||||
| Ultraviolet Sensor | ||||
| Water Resistance | 3 ATM | 5 ATM | 1 ATM | 5 ATM |
Notifications | ||||
| Phone | ||||
| Emails | ||||
| Texts | ||||
Software | ||||
| Operating System | n/a | NA | ||
| Apps | ||||
| Music | ||||