Fitbit Flex features five LED indicator lights. The lights behave differently depending on what the tracker is doing.
The indicator lights illuminate as you hit 20% increments towards your goal. Tap your Flex to see your progress. When you reach your goal, Flex will celebrate by buzzing and flashing its lights.
For more information, see How do I change the primary goal on my Flex?
When you tap your Flex rapidly for one or two seconds to enter sleep mode, it will vibrate and display two slowly dimming lights. During sleep mode, two blinking lights alternate. After you tap your Flex rapidly to exit sleep mode, it will vibrate and flash all five lights three times and then display a spinning light pattern. For more information, see How do I track my sleep?
While your Flex is charging, an indicator light will pulse to show the battery level every few seconds.
Each indicator light represents progress towards the total charge. When the Flex has charged completely, all 5 indicator lights will blink. For more information, see How do I charge my Flex?
If an update fails to complete, your Flex's LED indicator lights may cycle back and forth repeatedly, from left to right, and your Flex no may longer respond to taps, charging, or resets. If this occurs restart your tracker using the instructions at How do I restart my tracker?
If an update still fails to complete, try updating using a different method; for example, if you were updating using Fitbit Connect on your computer, try updating using the mobile app. If this fails as well, contact Customer Support
for further troubleshooting.
When a silent alarm goes off, the Flex vibrates and the center light flashes. For more information, see How do I manage silent alarms with Flex?