A Fitbit Inspire 3 syncs its steps, sleep and heart rate to the Fitbit app on a phone over Bluetooth, and when it stops syncing the cause is a broken link between the tracker and the phone, a permission that the app has lost or a stuck state in either device. Start with the phone. Open the Fitbit app, pull down on the Today screen to force a sync, and look at the device's status on the account screen, which shows when the tracker last synced.
The checks in more detail
Make sure Bluetooth is on and that the phone is within a few meters of the tracker. On Android, the app needs the Nearby devices and Location permissions, and on iPhone it needs Bluetooth permission, and a recent system update can reset these, so check Settings, Apps, Fitbit and allow them. Also check that battery saver or low power mode is not stopping the app in the background, because sync often runs when the app is not open.
If the basics are right, restart the tracker, following the steps in Fitbit's help for the Inspire 3, and restart the phone. Close the app fully and reopen it. Turn Bluetooth off and on, and on the phone remove the tracker from the Bluetooth device list if it appears there, since the Fitbit app manages the connection itself and a stale entry can interfere. Update the Fitbit app and the tracker's firmware, which the app does during a sync if the battery is above the required level.
Charge the tracker, because a low battery can stop sync. If the tracker was paired to another phone, or you recently changed phone, sign in on the new one and set the tracker up again, which keeps your history because it lives in your account. Sync only works when the tracker is connected to the account you are signed in to. If none of this works, remove the tracker from your account in the app and add it again, then contact Fitbit support if it still fails, giving the date of the last good sync.
Differential
Likely causes of “Fitbit Inspire 3 will not sync activity or data”, and how to tell them apart
- 1
Bluetooth is off or the phone is far away
What separates it The app shows an old sync time
How to confirm Turn Bluetooth on and keep the phone close
- 2
A lost app permission
What separates it Sync works only when the app is open
How to confirm Allow Nearby devices, Location and background activity
- 3
A stuck tracker
What separates it The tracker shows time but never syncs
How to confirm Restart the tracker
- 4
A stale Bluetooth pairing
What separates it A tracker entry in the phone's list
How to confirm Remove it there and let the Fitbit app reconnect
- 5
A new phone or account
What separates it The tracker is tied to another account
How to confirm Sign in and set the tracker up again
Before you touch a setting
Record this first — changing settings destroys the evidence
- The time of the last sync
- Whether Bluetooth is on
- The app permissions
- Whether the phone changed recently
Try in this order
0 of 6 completedPull to sync
ReversibleOn the Today screen.
Check Bluetooth and permissions
ReversibleNearby devices, Location and background.
Restart the tracker
ReversibleAs Fitbit's help describes.
Restart the phone
ReversibleAnd reopen the app.
Remove a stale pairing
ReversibleIn the phone's Bluetooth list.
Set up again
ReversibleIf you changed phone.
Model-specific
What is true of this model and not of its siblings
- Account
- Data lives in your Fitbit account.
- Permissions
- Nearby devices and Location are needed on Android.
Stop boundary
When this stops being a self-service repair
- !If the tracker will not sync after a restart and re-adding it, contact Fitbit support with the date of the last sync
- !Keep the app updated
- !Charge the tracker
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why is my Inspire 3 not syncing?+
Bluetooth, a lost permission or a stuck tracker.
Will I lose my data if I set it up again?+
No, history is stored in your account.
Does the app need to be open?+
Not always, but it needs background permission.
Should I pair it in Bluetooth settings?+
No, the Fitbit app manages the link.