Start with the simplest fixes first

Most Fitbit sync problems come from three things: your phone's Bluetooth is off, your Fitbit app needs an update, or you have not opened the app in several days. Before you reset anything, check those three in order. Turn Bluetooth on in your phone's settings, open the app store on your phone and search for "Fitbit" to see if an update is waiting, and then open the Fitbit app itself and wait 30 seconds to see if it syncs.

If none of that works, the next step is to force close the Fitbit app and reopen it. On Android, go to Settings > Apps > Fitbit, then tap "Force Stop". On iPhone, swipe up from the bottom of the screen to open the app switcher, find Fitbit, and swipe it away. Then open the app again and wait another 30 seconds.

These steps fix the problem about half the time. If your Fitbit still will not sync after this, move to the next section.

Key Takeaways

  • Turn Bluetooth on, update the Fitbit app from your app store, and force close and reopen the app before trying anything else.
  • Forget your Fitbit from your phone's Bluetooth settings and re-pair it if the app still will not sync after a force close.
  • Restart both your phone and your Fitbit device by holding the button or letting the battery drain completely, then charge it again.
  • If your Fitbit still will not sync after re-pairing and restarting, a factory reset of the device is usually the last step before contacting Fitbit support.
  • Sync problems often return if you do not open the Fitbit app at least once every few days, even if you have automatic syncing turned on.

Forget and re-pair your Fitbit through Bluetooth

If force closing the app did not work, your phone's Bluetooth connection to your Fitbit may be corrupted. The fix is to remove the device from your phone's Bluetooth list and pair it again from scratch. On Android, go to Settings > Bluetooth, find your Fitbit device in the list, tap the gear icon next to it, and select "Unpair" or "Forget". On iPhone, go to Settings > Bluetooth, find your Fitbit, tap the "i" icon, and select "Forget This Device".

Once you have forgotten the device, open the Fitbit app and go to the profile icon in the bottom right corner. Tap "Set Up a Device" and follow the steps to pair your Fitbit again. Your phone will ask for permission to use Bluetooth — tap "Allow". This usually takes two to three minutes.

After re-pairing, wait 30 seconds and check whether your Fitbit syncs. If it does, you are done. If it does not, move to the restart section.

Restart your phone and your Fitbit device

A restart clears temporary memory on both devices and often fixes sync problems that re-pairing did not solve. Restart your phone the normal way — power it off completely, wait 10 seconds, and turn it back on. While your phone is restarting, restart your Fitbit. The method depends on which model you have: most Fitbits have a button on the side or back that you hold for 10 to 15 seconds until you see the Fitbit logo on the screen. Some older models require you to let the battery drain completely, then charge it again.

Once both devices are back on, open the Fitbit app and wait 30 seconds. If your Fitbit syncs, the problem is solved. If it still will not sync, check the next section.

Check your Fitbit battery and account sign-in

A Fitbit that is nearly out of battery will not sync, even if it still turns on. Charge your Fitbit for at least 30 minutes before trying to sync again. While it charges, sign out of the Fitbit app on your phone: go to the profile icon, scroll down, and tap "Sign Out". Then sign back in with your email and password. This refreshes your account connection and sometimes fixes sync issues that come from a stale login.

After you sign back in, make sure your Fitbit is charged to at least 50 percent, then open the app and wait 30 seconds. If your Fitbit syncs now, you are done. If it still will not sync after a full charge and a fresh sign-in, a factory reset is usually the next step.

Factory reset your Fitbit as a last resort

A factory reset erases all data on your Fitbit and returns it to the state it was in when you first unboxed it. You will lose any data that has not synced to your account, so make sure you have synced at least once before doing this. To factory reset, go to the Fitbit app, tap your profile icon, select your device, scroll down to "About", and look for "Clear User Data" or "Factory Reset". The exact wording varies by model.

Tap that option and confirm. Your Fitbit will restart and show a setup screen. Follow the on-screen steps to pair it again as if it were new. This usually takes five to ten minutes. After setup is complete, wait 30 seconds and check whether it syncs. Factory resets fix the problem in most cases where re-pairing and restarting did not.

What to do if nothing works

If your Fitbit still will not sync after a factory reset, the problem is likely a hardware issue with your device or a persistent account problem that requires Fitbit support. Contact Fitbit through the app by tapping your profile icon, scrolling to the bottom, and selecting "Contact Us". You can also visit fitbit.com/support and choose your device model to see support options. Have your device serial number ready — you can find it in the app under your device settings.

Before you contact support, write down the exact steps you have already tried: the app version number (visible in the app settings), your phone model and operating system version, and when the sync problem started. This information helps support troubleshoot faster.

Prevent sync problems from happening again

Fitbit sync problems often return if you do not use the app regularly. Open the Fitbit app at least once every three days, even if you have automatic syncing turned on. Automatic syncing works only when your phone and Fitbit are in range and Bluetooth is on, but opening the app manually forces a sync regardless. Keep your Fitbit app updated by checking your app store once a month for new versions.

If you use multiple phones or tablets with the same Fitbit account, sync problems are more likely. Stick to one primary device if you can. If you must use more than one, make sure only one device has Bluetooth pairing active at a time — forget your Fitbit from the other devices' Bluetooth settings.

Frequently Asked Questions

Why does my Fitbit sync sometimes but not other times?

Intermittent syncing usually means your Bluetooth connection is unstable or your phone is too far from your Fitbit. Keep your phone within 30 feet of your Fitbit and make sure Bluetooth stays on. If the problem persists, re-pair your device and restart both your phone and Fitbit.

Will I lose my data if I factory reset my Fitbit?

You will lose data that has not synced to your account yet. Before you factory reset, open the Fitbit app and wait for it to sync at least once. Any data that reached your account will stay there even after the reset.

Can I use my Fitbit without the app?

Your Fitbit will track steps and other metrics without the app, but you will not see the data unless you sync it. The app is required to view your stats and change device settings. Syncing through the app is the only way to back up your data.

What if my Fitbit pairs but still will not sync?

If pairing works but syncing does not, sign out and back into the Fitbit app, restart your phone, and make sure your Fitbit battery is above 50 percent. If that does not work, try a factory reset. A sync problem after successful pairing usually points to a software issue rather than a Bluetooth connection problem.

How long does a Fitbit usually take to sync?

A normal sync takes 10 to 30 seconds once your phone and Fitbit are connected. If syncing takes longer than a minute, force close the app and try again. Slow syncing can mean your Bluetooth connection is weak or your phone is running low on memory.