Fitbit Won't Sync? FIXED! Here's the Ultimate 12-Point Troubleshooting Guide

Last updated: November 5, 2025

You wake up one morning, ready to check your sleep score and daily steps, but your Fitbit isn’t syncing! It’s stuck “Looking…” or showing an old timestamp, meaning your latest workout, heart rate, or sleep data is missing. It’s frustrating, but nearly always fixable.

The problem is rarely a single issue. Synchronization relies on a perfect alignment of Bluetooth, Internet, App Settings, and Device Power. When one of these fails, the sync breaks.

We’ve compiled the ultimate 12-point checklist to fix the dreaded Fitbit Won’t Sync Error, starting with the simplest restarts and moving up to advanced device-specific solutions.

Table of Contents

Phase 1: The Essential Resets (Try First!)

These simple restarts resolve about 70% of all sync issues by clearing temporary communication glitches.

1. Force a Manual Sync

If your tracker is currently connected, force it to wake up and sync.

Open the Fitbit App on your phone.
Go to the Today tab (dashboard).
Pull down on the screen and hold until you see the progress bar or the spinning circle. Release and wait for the sync to complete.

2. Toggle Bluetooth OFF and ON

This forces your phone’s Bluetooth radio to refresh the connection stack.

Go to your phone’s Settings or Control Center / Quick Settings.
Turn Bluetooth OFF for at least 10 seconds.
Turn Bluetooth ON and re-open the Fitbit app to initiate a sync.

3. Force Quit the Fitbit App

Ensure the app isn’t stuck in a corrupted background state.

iPhone: Swipe up from the bottom (or double-tap the Home button) to view open apps, then swipe up on the Fitbit app card to close it.
Android: Go to Settings $\rightarrow$ Apps $\rightarrow$ Fitbit $\rightarrow$ Force Stop.
Relaunch the app and attempt to sync.

4. Reboot Your Phone and Fitbit Tracker

The classic IT solution—turn everything off and back on again—is surprisingly effective.

Reboot your Phone: Power it down completely, wait 30 seconds, and turn it back on.
Restart your Fitbit: Plug your device into its charging cable, then follow the manufacturer’s specific restart procedure for your model (usually a button press for 8–10 seconds). (A restart is a soft reboot and does not erase your data).

Phase 2: Advanced Connection Checks

If the basic resets failed, the issue is likely rooted in your phone’s settings or conflicting connections.

5. Check Internet and Device Power

Internet Connection: The Fitbit app must have a stable Wi-Fi or cellular connection to upload your data to the cloud. Double-check your Wi-Fi is on and working.
Fitbit Charge: Your Fitbit’s battery must have at least a 25% charge for the sync process to complete successfully. Put it on the charger and try syncing again.

6. Remove and Re-Pair the Device (The Best Fix)

This forces a clean, fresh connection between your phone and your tracker.

A. Forget in Bluetooth: Go to your phone’s Settings $\rightarrow$ Bluetooth. Find your Fitbit device in the list and select Forget This Device or Unpair.
B. Remove in App: Open the Fitbit app, tap your Profile Picture $\rightarrow$ Select your Fitbit Device $\rightarrow$ Scroll down and select Remove [Device Name].
C. Re-Pair: Tap your Profile Picture $\rightarrow$ Set Up a Device $\rightarrow$ Follow the on-screen steps to reconnect your Fitbit.

7. Disable Android Battery Optimization (Critical for Android)

Modern Android operating systems are very aggressive with battery-saving, often killing the Fitbit app’s background sync process.

Go to Settings $\rightarrow$ Apps $\rightarrow$ Fitbit $\rightarrow$ Battery.
Change the setting from Optimized/Restrict to Unrestricted (or “Don’t optimize” on older versions). This allows the Fitbit app to run in the background without the OS cutting it off.

8. Verify App Permissions (Location & Background Refresh)

Fitbit requires Location Services to scan for Bluetooth devices on Android and continuous background access on iOS.

iPhone: Go to Settings $\rightarrow$ General $\rightarrow$ Background App Refresh $\rightarrow$ Ensure Fitbit is ON.
Android: Go to Settings $\rightarrow$ Apps $\rightarrow$ Fitbit $\rightarrow$ Permissions. Ensure Location is set to “Allow all the time” (or similar).

9. Check for Competing Devices

A Fitbit can only sync to one device at a time.

If you have an old phone, tablet, or PC that previously synced with your Fitbit, make sure its Bluetooth is OFF or the Fitbit app is uninstalled on that device.

Phase 3: Final Software Overhauls

If nothing above worked, it’s time to refresh the core software.

10. Update Everything

Outdated software is a common cause of unexpected sync failure.

Update your Fitbit App: Check the Google Play Store or Apple App Store for the latest version.
Update your Fitbit Tracker: Check the Fitbit app for any pending firmware updates for your device.
Update your Phone OS: Ensure your phone is running the latest version of iOS or Android.

11. Clear Cache and Reinstall App

A full reinstall ensures you have a clean, non-corrupted copy of the app.

Android Only (Clear Cache): Go to Settings >Apps > Fitbit > Storage > Clear Cache (Do NOT tap “Clear Data”).

Uninstall and Reinstall: Delete the Fitbit app from your phone. Restart your phone. Re-download and install the latest version from the app store, log in, and try syncing.

12. Factory Reset the Fitbit (Last Resort)

This is a final, nuclear option that clears all data stored on the tracker itself (but your already-synced data remains safe in the cloud).

Before you begin: Ensure your device is fully synced before resetting.
Modern Models (Sense, Versa, Charge 6/5, etc.): You can usually find the option in the device’s settings: Settings App > About/Device Info > Factory Reset or Clear User Data.
Older Models: The process is a combination of charging cable connection and button presses. Search for the specific procedure for your Fitbit model on the official Google/Fitbit support site.
After the factory reset, you must set up your device again as if it were brand new.

FAQs on Syncing

Question	Answer
What is a “restart” vs. a “factory reset?”	A restart is a soft reboot (like turning a PC off/on) that fixes minor glitches without losing data. A factory reset wipes all user data and settings from the tracker, returning it to its original state. Always try a restart first.
Does the Fitbit App need to be open to sync data?	No. The app is designed to run in the background and sync periodically. However, on Android, you must ensure Battery Optimization is set to “Unrestricted” (see step 7) for this to work reliably.
Can I sync my Fitbit to two phones?	No. A Fitbit tracker can only be actively paired and synced to one phone or tablet at a time. If you switch phones, you must remove the device from the old phone and then set it up as a new device on the new one.
Why is my Fitbit clock time wrong?	Your Fitbit gets its time from your phone’s time and date settings upon sync. If the time is wrong, perform a manual sync (Step 1). If the time zone is incorrect, go to the Fitbit app $\rightarrow$ Profile $\rightarrow$ App Settings $\rightarrow$ Time Zone and select the correct one.

Fitbit Won’t Sync? FIXED! Here’s the Ultimate 12-Point Troubleshooting Guide

Technical Skills Everyone Should Have

What Is A Dangerous Temperature For A CPU? Warning Signs

MPEG Noise Reduction: What It Is and How to Use It