You may think you've turned off your phone's Wi-Fi but, a technology expert warns, your phone could still be using Wi-Fi services in the background.

As explained in a widely circulated TikTok video published on Saturday by user @tatechtips, Android phones will still use Wi-Fi scanning for more accurate location services, even if the phone's Wi-Fi is turned "off."

"That means when you've got your Wi-Fi off … your phone is constantly still sending out probe requests for Wi-Fi," he said in the video.

But turning off this feature can add "an extra level of privacy," @tatechtips says, as you may not want your apps to have your precise location data. Turning Wi-Fi off completely can also help preserve your phone's battery life.

Android user who want turn off this feature can navigate to "Location Services" in the phone settings and toggle Wi-Fi scanning off.

This video was posted a week after pushed a software update for iPhones, iPads and Macs, patching a serious security flaw that could allow hackers to gain full control of a device.

Similar to Android devices, turning the Wi-Fi off from the Control Centre pull-down menu on iPhone won't completely turn off the phone's Wi-Fi. Just like on Android devices, the iPhone can still use Wi-Fi services for location data, and other Wi-Fi-dependant services like AirPlay and AirDrop will continue to function.

To fully turn off Wi-Fi, iPhone users can go into the settings app and turn off Wi-Fi from there rather than using Control Centre.