When using the Fitbit app to sync Fitbit devices, there are small amounts of data transferred during each sync that will count against a participant's data plan. Internal testing has confirmed that the daily amount of data transferred during consistent syncing (using the "All-Day Sync" option should be minimal.
- For the Flex 2 (a device with no heart rate), the data fetch range is 1 KB – 340 KB per day, which translates to approximately 10.2 MB per month.
- For the Charge 2 (a device with heart rate), the data fetch range is 1 KB – 3.3 MB per day, which translated to approximately 99MB per month (or .1GB)
For best results, we recommend using wifi for syncing whenever possible to limit the amount of data transfer that may count against a data cap.