What should I do if my Fitbit doesn't synchronize?
Update your phone
You may need to run a software update on your phone and this could be why your Fitbit doesn't synchronize. If your smartphone isn't up to date, some functionalities may not be working.
Check if Bluetooth is on
If your Fitbit doesn’t synchronize, check if Bluetooth is turned on on your phone and Fitbit. If Bluetooth is turned off on 1 of these devices, they can’t connect.
Check if your phone is connected to other devices
If your smartphone is connected to other devices, such as a music installation or headset, it's possible that the connection between your phone and activity tracker is lost. Check the Bluetooth menu to see which devices your phone is connected to and disconnect them.
Check if your Fitbit is connected to other devices
Your Fitbit tracker can only connect to 1 device. Make sure the tablet or your partner's phone isn’t connected to your Fitbit, for example.
Perform a hard reset
Hard reset iPhone
Close the Fitbit app. Go to settings > Bluetooth and turn Bluetooth off and back on. Open the Fitbit app and check whether the Fitbit is synchronizing. Didn't work? Turn off your iPhone and check whether it's synchronizing now. Still didn't work? Log in to your Fitbit account on a computer or another smartphone and try to synchronize from there. If this doesn't work, remove all devices from your account and from your list of connected Bluetooth devices. Connect the Fitbit to your smartphone again.
Hard reset Android
Close the Fitbit app and start again. Go to settings > Bluetooth. Turn Bluetooth off and back on. Open the Fitbit app. If your Fitbit still doesn't synchronize, restart the Fitbit app. Check again. Uninstall the Fitbit app and reinstall it. Log in to your Fitbit account from a computer or another smartphone and try to synchronize again. If this doesn't work, remove all devices from your account and from your list of connected Bluetooth devices. Connect the Fitbit to your smartphone again.