Basic Info |
| Suggested Price | $120 | $299 | $349 | $99 | $429 |
| Release | 2015 | 2017 | 2015 | 2016 | 2021 |
Activity & Fitness |
| Calories | | | | | |
| Cycling (Bicycling) | | | | NA | |
| Distance | | | | | |
| Heart | n/a | | | | |
| Oxygen | | | | | |
| Sleep | | | | NA | |
| Steps | | | | | |
| Swim | | | | | |
Battery |
| Duration | 8 days (without notifications) | 4+ days | 18 hours | NA | 18 Hours |
| Rechargeable | | | | | |
Compatibility |
| Android | | | | | |
| iOS | | | | NA | |
| Windows Phone | n/a | | NA | NA | |
| Mac | n/a | | NA | NA | |
| Windows | n/a | | NA | NA | |
Connectivity |
| Bluetooth | | | | | |
| Cellular | | | | | |
| GPS | | | | | |
| NFC | | | | | |
| Wi-Fi | | | | | |
Display |
| Color | | | | | |
| Resolution | n/a | 348x250 | 340 x 272 or 390 x 312 | NA | 396 x 484 |
| Size | n/a | 1.42 | 1.5 inches or 1.65 inches | NA | 1.9 inches |
| Touch | | | | NA | |
| Type | LED | OLED | AMOLED | NA | MicroLED |
Functions |
| Audio Speaker | | | | | |
| Clock | | | | | |
| Phone | | | | NA | |
| Vibration | | | | NA | |
| Voice | | | | | |
Hardware |
| Accelerometer | | | | NA | |
| Barometer or Altimeter | | | | | |
| Ultraviolet Sensor | | | | | |
| Water Resistance | 2 ATM | 50m | IPX7 | NA | water resistant but not waterproof |
Notifications |
| Phone | | | | NA | |
| Emails | | | | NA | |
| Texts | | | | NA | |
Software |
| Operating System | n/a | Fitbit OS | Watch OS | NA | WatchOS 8 |
| Apps | | | | | |
| Music | | | | | |
