How trackers actually work

Bluetooth crowd-network tags. The tag broadcasts a rotating identifier a few times a second. Any participating phone that hears it submits an encrypted report of where it was heard, and you see the result. The tag has no idea where it is, consumes almost no power, and costs nothing to run. Its usefulness is a direct function of how many participating phones are near it, which is why it is superb in an airport and useless on a ridge.

Cellular GPS trackers. A satellite receiver works out the device's own position; a cellular modem sends it. This works with nobody else present, which is the entire value, and the cellular data is the entire cost. Power consumption is in a different league: a tag runs a year on a coin cell, a cellular tracker runs days to months on a rechargeable pack depending on how often it reports.

Radio direction-finding. A handheld unit and a collar unit talk directly over license-free radio. There is no network, no SIM, no servers and no subscription. Range is long in open country and short around buildings, and the position only exists on the handheld in your hand — there is no map you can check from work. For hunting dogs and genuine dead zones this is the only thing that works, which is why professional kit still uses it.

The manufacturers' figures are honest and they are also not comparable, because they measure different things under different assumptions.

Apple's "more than a year" for an AirTag is based on everyday average usage of playing sound and Precision Finding, and Apple says so in its own footnote. Ring your keys fifteen times a day and you will not get a year. Samsung's "up to 500 days" for the SmartTag2 is a different usage model again. Chipolo's "about a year per charge" and Pebblebee's "up to 12 months" are rechargeable figures, which depend on how often the tag is woken.

For cellular trackers the variable is reporting interval, and it dominates everything else. The same hardware can last a week reporting every sixty seconds or four months reporting twice a day. A manufacturer quoting 140 days is quoting a long interval; a manufacturer quoting a week is quoting a short one. Neither is lying and the numbers cannot be compared without the interval attached.

The practical rule: treat every battery figure as an order of magnitude rather than a promise. Tags last about a year. Cellular trackers last days to months and you will be charging them.

Both major platforms now detect unwanted trackers automatically, and both do it well for the devices they cover.

On iPhone, you get an alert when an AirTag, a set of AirPods or a Find My network accessory that is not yours has been separated from its owner and seen moving with you over time. Apple's requirements are specific: iOS 17.5 or later, Location Services on with Significant Locations enabled, Bluetooth on, Tracking Notifications enabled and Airplane Mode off. Tapping through lets you play a sound, use Precision Finding on a UWB iPhone to walk to it, and get instructions to disable it. Turning off your own Location Services or Bluetooth does not stop the owner tracking the device — only disabling the device does.

On Android, the equivalent lives under Settings, Safety & emergency, Unknown tracker alerts. It covers Find Hub tags and Apple AirTags, plus Chipolo, Motorola and Pebblebee devices, and includes a manual Scan now that takes about ten seconds and works on Android 11 and later without Location Services enabled. Google's own guidance notes that turning some trackers off triggers a factory reset, which can prevent law enforcement identifying the owner — worth knowing before you disable one.

What both systems miss is the entire cellular category. A hidden cellular GPS tracker does no Bluetooth beaconing, so neither platform's scan will ever see it. Finding one of those means a physical search or an RF detector, and an RF detector only works while the device is actually transmitting — many sleep when the vehicle is stationary. That gap is real and it is why our detection pages cover both methods separately.