Fitbit Flex Not Syncing: How to Fix

There are many reasons why you should love the Fitbit Flex. Asides from being lightweight, the watch syncs wirelessly with your mobile device.

Although it is designed to be an easy process, pairing both devices isn’t always easy. However, there are several ways that you can deal with this issue.

Do you have a Fitbit Flex with syncing issues? If yes, then you can deal with such problems by using our guide.

fitbit flex not syncing

Fitbit Flex Not Syncing: DIY Fixes

Here are some of the best ideas for fixing the Fitbit Flex. But before using our guide, we suggest that you check the owner’s manual for additional advice.

1. Reset the Flex

Before trying any hacks, it would help if you reset the Fitbit Flex. After all, this step allows you to remove any bugs that caused the syncing issues. Now here are the best steps for performing a reset on the Fitbit flex.

  1. Insert the charging cable into your PC.
  2. Plug the Flex into the charging cable
  3. Insert a paperclip into the hole at the back of the charger
  4. Hold the paper clip for 3 – 5 seconds
  5. Disconnect the charger from the watch

2. Switch on the Bluetooth

As you connect the Fitbit Flex with a smartphone, make sure the Bluetooth of the mobile device is turned on. But as there are various phone models, there are also several ways to turn on the Bluetooth on these devices.

If you are using an iPhone:-

  1. Click on Settings – Bluetooth
  2. Tap the toggle switch at the side of the Bluetooth

If you are using an Andriod device:-

  1. Scroll to Settings – Connection – Bluetooth
  2. Toggle the switch at the side of the Bluetooth option

3. Restart the Mobile Device

If you are still having sync issues with your watch, it would help if you restarted the device on which you installed the Fitbit app. With this hack, the phone should easily pair your smartphone.

If you are restarting an iPhone:

  1. Press and hold the Side button
  2. Wait for the Power Off Slider to appear
  3. Drag the slider and wait for the device to go off

If you are restarting an Andriod device:

  1. Hold the Power and Volume Down Buttons
  2. Choose the Restart button
  3. Wait for the phone to restart

4. Update the Fitbit App

If Fitbit Flex has any sync issues, deal with them by updating the Fitbit app. As you use this idea, make sure you pick its latest version.

For Andriod devices:-

  1. Hit the Playstore app
  2. Hit the Menu icon at the upper corner of the app.
  3. Select My Apps & Games
  4. Check the Update list for the Fitbit app. If you find the app, hit the Update button beside it.

5. “Forget” the Watch

If your Fitbit Flex still has issues, then it would help if you removed it from the list of paired Bluetooth devices (on your phone). Then attempt to reconnect both devices and see if the watch can sync with your mobile device.

6. Sync the Watch with Your PC

Before syncing your watch with your mobile device, you should try to sync it with a computer. For the best results, you should try the following steps with an Andriod device:-

  1. Download the PC version of the Fitbit app
  2. Sync the PC with the watch
  3. Sync the watch with your smartphone

7. Force Quit the App

Are there still issues with syncing your watch? If yes, then you could force quit the app. You can check the owner’s manual for the best steps for performing this operation.

8. Charge Your Device

As soon as you have a low battery, the Fitbit starts to preserve its power. For this task, the watch has to stop syncing with other Bluetooth devices. So if your watch has run out of juice, try to charge it before syncing it with the mobile device.

9. Update the Software on Your Phone

With the latest version of your phone software, you can handle any issues that might affect the sync. If you are not sure about the right steps for upgrading your device,  you can check its owner’s manual.

10. Contact the Fitbit Customer Support

Supposing our hacks do not work with your device, we recommend that you reach out to Fitbit Customer Service. As expected, this service provides the best fixes for any Fitbit Flex issues. You can reach the service via mail, telephone, or by dropping a complaint on the Fitbit website.


  • Keith Rowland is a seasoned electrician who enjoys fixing faults in home appliances and electronics. Being someone who loves writing, he shares on this blog, DIY tips on how to fix various devices within a few minutes. When he's not fixing stuff or writing a new blog post, he's playing with his two cute girls and their mom.