I just updated my Nexus 5 to Lollipop, and the feature I'm most anticipating is Smart Lock — the ability to keep my phone unlocked when it's near me but still have strong protection if lost or stolen.

I figured that since I have a Fitbit One in my pocket pretty much whenever I have my pants on, I'd use that as the "key". It syncs by Bluetooth, so I figured I'd be all set.

However, when I go into Smart Lock in the settings and attempt to add a Trusted Device, it doesn't show up in the list. Why not?


8 Answers 8


In order for a Bluetooth device to work with smartlock, it needs to be constantly connected while it's within range of your phone. Dedicated smart watches, Bluetooth speakers, and your cars Bluetooth are constantly connected to your phone to pass data (calls, texts, music, notifications). For a lack of better term, the Bluetooth connectivity is "active" (always connected) for these devices.

Fitbit on the other hand only connects periodically and only for a few seconds to sync health data. So basically Bluetooth connectivity is in "sleep" mode (disconnected) until the timer activates Bluetooth to sync health data and then disconnects again after it's done.

There is an option for your fitbit device to notify you of incoming calls, however this still doesn't maintain Bluetooth connectivity. When you get a call, your phone temporarily activates Bluetooth to send the signal and then disconnects. This is why your fitbit gets a delayed notification instead of an instant notification like a true smart watch which has permanent Bluetooth connectivity.


Bluetooth Low Energy devices can be used for Smart Lock, but they need to be paired at OS level and it seems that the Fitbit uses some kind of pseudo-pairing at app level. From the Fitbit manual:

Unlike standard Bluetooth devices, like headsets, your Fitbit tracker will be set up directly through the Fitbit app and not through your Android device's Bluetooth pairing settings.

  • 1
    Note that you can pair a fitbit device (use code 0000), but it still does not work with Smart Lock.
    – doc
    Commented Apr 6, 2015 at 21:45
  • @doc How would one do that? I'm not seeing it under "Available devices" on the Bluetooth screen .
    – mattdm
    Commented Apr 6, 2015 at 21:49
  • 1
    Try tapping the fitbit until the lights come on and then seeing if it appears as a device
    – doc
    Commented Apr 7, 2015 at 10:53

Lollipop does not appear to allow Bluetooth Low Energy devices to be used for Smart Lock. I believe that Fitbits are devices of this type.

I have a similar issue with one of Fitbit's rivals - I've successfully set up Smart Lock with "normal" Bluetooth devices such as a speaker in my kitchen - i.e. ones that show a connection in the bluetooth settings - but I'm unable to do it with my UP24 band.

  • Do you have any document which said about BLE cannot uses for smart lock?
    – Jame
    Commented Nov 21, 2016 at 9:04

I was able to pair my Fitbit Surge with my phone, but I have only had it work with Smart Lock when Fitbit was running on my phone. Once I close the app, I have to start entering my code again.

UPDATE! - I discovered that my watch has an option for Bluetooth (Classic). I synced my phone to Surge (Classic) and I can now unlock my phone at anytime while wearing my Fitbit Surge. = Happiness :)

This will probably make my watch battery last a shorter time, but the trade off is worth it to me.


I've got a fitbit HR and I've found smart unlock is available after I changed the "enable notification widget" setting in the call notification menu to on. This burns more battery but it's a trade off I'll gladly take for not having to enter a pin every time I open my phone.


I had to pair my fitbit surge through the bluetooth panel, and then it showed up as an option for smart unlock. This might help with the fitbit one?


I have a Charge 2. My solution is to sync using the Fitbit app and then add as a trusted device. This method also works when Smart Lock times out after 4 hours of inactivity.


As @Warbert noted in the accepted answer, Smart Lock requires a current bluetooth (BT) connection. Devices like Fitbit try to minimize BT connection duration to maximize Fitbit battery life.

But the latest Fitbit android app has an "Always Connected" option that tries to force the Fitbit device to maintain the connection. This works well with my Fitbit Alta HR. FYI, the setting is per device paired with the app, so it's kind of "deep" in the app to get to the setting for the Fitbit device.

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