How, exactly, do Airtags work?

I’ve read some articles that say Airtags use Bluetooth technology and Apple’s ‘extensive network’ to track them, but I’m not sure exactly how they work. I know that if I connect a device to my computer, I need to pair it. [NB: I’ve only paired a mouse to one computer, and I paired my phone to the car before I found it inconvenient.] I’m guessing Airtags work like RFID, where it ‘pings’ if it gets near a reader. I know that my computers need to be turned on and near a WiFi source in order to be tracked. (I have both of them, and my iPhone, in my Find My app.)

So what’s with Airtags? Are they always on? Do they communicate with cell towers and WiFi signals all the time? Do they only work if they’re in the presence of someone’s iPhone? Basically, when do they work, and when do the not? How are the ways they are tracked?

You can read the paper, but, basically,

No. You might say they indeed ‘ping’, but it is not RFID and has nothing to do with special readers, except that you do pair them with your Apple computer/phone.

They contain a CR2032 battery, so they do have their own power and are “always on”. They broadcast bluetooth packets, however:

Bluetooth Low Energy, not what you listed

iPhones, iPads, any Apple devices with the requisite Bluetooth capabilities

The Apple devices receive those advertisement beacons from the Airtag, which contain a public key, and upload (possibly not immediately; it could take a little while) an encrypted report to Apple servers. If you have the right Apple ID and private keys you can download those location reports and figure out where your Airtag is/was.

The upshot being that bluetooth tags are useful only if you want to track things in a densely populated area, useless otherwise. There exist GPS tags that don’t depend on the presence of other humans nearby, but they consume I think at least an order of magnitude more power.

ETA: maybe I’m wrong about the power thing - I’ve never actually used one, and I see the Galaxy SmartTag device claims “up to 500 days”. I may have to try these out, I was thinking about it a few months ago.

Are you sure it has GPS? I would expect the GPS model to have a much shorter battery life than the regular model.

That was what I thought too, so maybe it’s bullshit. Definitely GPS, but it has bluetooth integrated, so perhaps the battery life “estimate” is based on dubious assumptions about bluetooth working 99% of the time and GPS only kicking in rarely as a backup. Still, if they can make it work that way with minimal power consumption when GPS isn’t needed, it’s still maybe a good device.

OK, if I’m reading that correctly, the Airtag is continually in contact, via Bluetooth, with (for example) my iPhone. Let’s say I hide one on a motorcycle. As long as I’m in proximity to the vehicle, and have my iPhone, the motorcycle is not ‘lost’. If I go inside the house, the device says, ‘I’m lost!’ and ‘advertises’ its location to any other Bluetooth receiver. I can use Find My to locate it. The Airtag keeps ‘advertising’ as long as it’s ‘lost’, but it doesn’t do any good unless someone, somewhere, has a Bluetooth-connected device somewhere nearby. The owner of the ‘finder’ device doesn’t know the device has received a signal from the Airtag, and the device uploads encrypted location information to the Cloud where my device (e.g., iPhone) can access that information and receive an approximate location. (I have an iPhone SE, so I don’t think I can use precision finding.) Do I have that right?

If I am correct above, that makes sense. A lot of people in densely-populated areas are using Bluetooth (e.g., for their ear buds), but there would be fewer people using Bluetooth in a rural area.

The tags they use to track migratory wildlife are not Airtags or Bluetooth tags, let’s put it that way, unless there are special new high-tech tags that I have not heard about.

ETA we were actually talking about GPS tags… you can get, say, GPS Iridium tags or other GPS satellite tags, but I could not tell you off the top of my head what the battery life is. You can program them to take locations at particular intervals, not continuously, so they will not constantly drain the batteries.

Yes, except the “finder” does know that. You can examine the raw bluetooth packets, and there are apps that will warn you if a tag is “stalking” you.

Hell, iOS devices will tell you that you have an unknown AirTag traveling with you. And the AirTag itself will start to beep. That’s why they’re bad anti-theft devices. They’re designed to be used to help you find items you’ve lost, not items that have been stolen.

Right, but Apple or the tag provider is not proactively telling them, they are by default an unaware node in a network through which information passes. Presumably you agree to be part of this network in one of the pages of tiny print that you tick at some point somewhere.

Which makes me wonder - can you opt out of the network?

Our dogs wear Fi collar devices which use GPS for locating them. A fully charged collar lasts a few weeks, then needs recharged for a few hours. We’ve played around with AirTags but they are pretty much useless for tracking our dogs due to terrain, I think.

As best I can tell, the Galaxy SmartTag+ and 2 are just Bluetooth low energy devices, like the Apple AirTag. The primary difference is AirTags require you have an Apple device, and SmartTags require you have a Samsung phone.

Any claim of “GPS” are just using the GPS of the phone that hears the Bluetooth signal from the tag.

In my experience they’re useful for determining the general location of something, but not good at precision: “the violin is at school,” or “your jacket is someplace in the house.” On AirTags, at least, the direction aspect is pretty poor. The arrow on the phone might point the opposite direction of the tag, and the range will be off by tens of feet.

Ah, that makes perfect sense. Very misleading I think, in addition to the battery life I couldn’t figure out how they could be so inexpensive.

So does a receiving device alert the user, or not? Does the user have to turn something on that says ‘Alert me if an unknown device tries to connect’? That is, does a receiver definitely know an Airtag or other BLE device is calling for help? Or is it that they can know if they want to?

On an unmodified iPhone you are supposed to (there is a menu option) at least be able to completely disable Location Services or control access to it for individual apps (like Find My; there is also a separate menu option to disable Find My), as well as turn off Bluetooth, but absent further detailed information about specfic models and OS versions I would not assume anything. For instance, even a “powered-off” iPhone may be quite active.

Not quite. An AirTag is always broadcasting its signature via BLE and UWB to any iOS device nearby (or any device iOS or not if the user is scanning for BLE packets). The “Find My…” backend is always integrating all the location reports for a given AirTag, whether reported by your device or someone else’s.

After about 8-12 hours of an AirTag not ‘seeing’ your device, it will start beeping as an anti-stalking precaution. Somewhere between 0-12 hours, the user’s iOS device will also notify the person(s) that the AirTag is with that they are accompanied by an unknown AirTag, also as an anti-stalking measure. Any reasonably competent thief knows this now and either scans for an AirTag right away or at a minimum knows to dispose of it when it starts beeping.

If you enable lost mode for that specific AirTag, the Find My network will notify anyone whose device spots that AirTag that it has been reported lost and will provide follow up info. The AirTag itself doesn’t do this, it’s the backend delivering the message to a potential finder.

The direction/range precision for Airtags is supposed to be on the order of centimeters if you use Ultra Wideband. Otherwise you have to get within Bluetooth range and make the tag beep so you can find it.

I am constantly misplacing my keys and with the AirTag attached, I am able to navigate to them with astonishing precision. As in, if they’re in a pocket of a pair of pants on the floor, it will take me to the correct pocket.

I read this article yesterday:

Gavino said when she pulled up her cellphone, the AirTag hidden inside her parents’ luggage showed it was on Interstate 85 and on its way west toward Gastonia.

The Gavino family then gathered the rest of their bags, picked up their rental car and began to follow the AirTag to a neighborhood, but said they were unable to find the exact location.

According to Gavino, AirTag had stopped displaying its location after a certain point.

The Gavino family canceled the search, but resumed it on Christmas Day, in hopes of having better luck…

So the Airtag had been with the thief, and out of contact with the owner, for at least a day. The owner found the thief’s house and called the police, who found another piece of luggage that had been reported stolen, and which had an Airtag. So either the thief was not ‘reasonably competent’, or else couldn’t hear the two devices.

They kind of bleep, not emit a piercing 100 dB alarm. However they can be “disabled” by removing the battery, and your linked article says the Airtag indeed ceased broadcasting at some point.