If you, as an iPhone owner, enable Lost mode for an AirTag, the iPhone will anonymously reach out to a vast network of compatible iPhones and iPads around the world. If any of these Apple devices is within 300 feet of your AirTag, you will be alerted to your AirTag’s location so you can retrieve your lost item. This process is encrypted and happens in the background, so the owner of an iPhone that locates your AirTagged item remains oblivious that their phone was involved.
For Android phone users, the popular Tile tracker offers a similar Bluetooth-enabled crowdsourcing process to find items outside the normal tracking range of several hundred feet and alert you via the Tile app. Notably, the CR2032 3V lithium coin battery that powers Apple Air Tags and Tile trackers is the same type of battery that powers many other items that often travel on planes, including watches, car key fobs and glucose monitors.