# How, exactly, do Airtags work? **URL:** \ **Category:** Factual Questions\ **Created:** [December 29, 2023, 3:48pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317 "2023-12-29T15:48:22Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [December 30, 2023, 2:11pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/41 "2023-12-30T14:11:09Z")
Thanks. I didn’t know that, though the alert is minor enough that I just glance at it and move on. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [December 30, 2023, 2:36pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/42 "2023-12-30T14:36:32Z")
> [@Riemann](#): > > Next you’ll be telling me that someone other than the TSA has access to the top secret keys that allow the TSA to open combination locks on luggage. Nobody does. Last time I locked my luggage (2006), TSA broke the zipper on the suitcase instead of cutting the lock, just to be dicks. > [@echoreply](#): > > You get a tracking notification if the tag is following you, not if you just happen to be near it. If at the house party you “accidentally” grab the wrong jacket with a tag in the pocket you’ll get a notification after it has been in several different locations with you but not it’s owner. Ah. The multiple location, multiple instances thing makes more sense. I can see false positives still happening but nowhere near as many. > [@Measure\_for\_Measure](#): > > Thanks. What if the stolen car is going one way and a car with an Apple is going the other? 30 MPH each way, 60MPH combined. Will the Airtag be detected? Of course the guy tailgating or stopped behind the stolen car at the light could easily give away the location, not to mention if Moriarty parks near a busy sidewalk or in a crowded parking garage. I’ve had my car grab my phone conversation from about 40 feet away, so yeah, that’s about normal range. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [December 30, 2023, 2:45pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/43 "2023-12-30T14:45:06Z")
My buddy dropped his brand new (white) earpods while we were ski touring last winter. We were lost, and when we found the right track and skied back to the truck he discovered his loss. We had no cell service, but once we got back in to service he could see right where they were. How does THAT work? Funny coda–he was going to skin the 2 miles up and retrieve them the next day. He checked the location and they were now at a **neighbor’s house!** The guy liked to skin around in the woods, happened to follow our wretched skin path, and happened to see the white case on the white snow. If that isn’t the mother of all coincidences, I don’t know what is! ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 30, 2023, 3:04pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/44 "2023-12-30T15:04:51Z")
> [@Tride](#): > > We had no cell service, but once we got back in to service he could see right where they were. How does THAT work? Presumably the device location and tracking service on his phone caches the location reports it was going to send and once it has cell or Wi-Fi connectivity, sends them all then. Had you also not been able to receive GPS positions up on the slopes then I suspect there would have been no location reports created then to send later when you got to the parking area and encountered a useable cell signal. ---
**Author:** ![Wolf333](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf333/32/3460_2.png) [@Wolf333](https://boards.straightdope.com/u/Wolf333)\ **Post date:** [December 30, 2023, 4:16pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/45 "2023-12-30T16:16:44Z")
Wretched Skin Path is my new band name. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [December 30, 2023, 5:54pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/46 "2023-12-30T17:54:13Z")
Are you saying the phone caches the last known location of the earpods? He did press “find my earpods” and they were in the middle of nowhere with no wifi within at least 5 miles and no cell service. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 30, 2023, 6:01pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/47 "2023-12-30T18:01:04Z")
If it was his own phone, then the Find My app will [assuming Location Services is enabled] display the last location where it saw the item, even without network connectivity. But you said they showed up at a neighbor’s house, so I assume they were back in range at that point. If they were 5000 miles away, you would have to download location reports from the server. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 30, 2023, 6:05pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/48 "2023-12-30T18:05:35Z")
ETA: ninja-ed by @DPRK I’m saying that the earpods or air tags or whatever are continuously pinging via Bluetooth “I’m alive; I’m alive. My name is [whatever] and I’m alive.” Any / all iPads or iPhones close enough to hear the Bluetooth signal record for themselves “At lat/long X (from the phone’s GPS) at time Y, I heard from the device named Z”. All those ping records are stored on the phone until the phone can connect to a cell tower or a wifi and send all that stored info home to Mama Apple. So his phone would know when and where it last heard from his earpods. Regardless of whether there was a cell or wifi signal there then. Exactly how the UI works and whether his phone would show him that data before it’s been synced to Mama Apple are details I’m not familiar with. The whole point of involving Mama Apple is that’s how other people’s i-devices can be enlisted to help find _your_ lost gizmo. And especially in the case where your gizmo has been moved since your i-device last talked with it to know where it was then. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [December 30, 2023, 6:12pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/49 "2023-12-30T18:12:46Z")
OK–that makes sense. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [December 30, 2023, 9:31pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/50 "2023-12-30T21:31:02Z")
I presume too, that if the item is pinging every, say, 2 seconds, then as you ski by their location, you get a “from… to” location (series of locations) off the phone’s GPS. If I were a programmer, I’d pick the middle of those two extremes as the proximate location. Can Bluetooth do someting like “I’m 25 feet from you bearing NNE”? (But more likely for the Airpods, they were right on the trail.) I presume they were location-reported from the neighbour’s house by his iPhone? ---
**Author:** ![echoreply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/echoreply/32/3641_2.png) [@echoreply](https://boards.straightdope.com/u/echoreply)\ **Post date:** [December 30, 2023, 11:29pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/51 "2023-12-30T23:29:02Z")
> [@md-2000](#): > > Can Bluetooth do someting like “I’m 25 feet from you bearing NNE”? Yes, sort of. As I mention above, with my Bluetooth only iPad it reports information like “25 feet, NNE,” but is not very accurate. Apperently ultra wide band does much better. I’ve played with things like Bluetooth lockers for my computer. If the computer thinks my phone’s Bluetooth signal is more than a few feet away, lock, when I return to range, unlock. It does not work very well. I can watch the range indicator bounce all over the place sitting in my chair. My car though, has something like 6 or 8 Bluetooth antennas and is very good at detecting how close a paired phone is. It can lock and unlock as appropriate, and even change the driver profile based on which phone is on the driver’s side of the car, in the front seat. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 30, 2023, 11:44pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/52 "2023-12-30T23:44:05Z")
> [@DPRK](#): > > 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. I’m not sure if any commercially available GPS tags do this yet, but there’s an interesting technique for improving battery life dramatically: just _record_ the GPS signal but don’t process it in any way; instead, just save it to flash memory. Since the processing of the signal is the energy intensive part (due to having to extract an extremely faint signal from the noise), the tag hardly consumes any power. It’s useless for, say, a smartphone, where you want to know where you are right at the moment. But useful for monitoring wildlife or the like, where you don’t need real-time positioning and can save the processing for a later step. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [December 31, 2023, 2:16pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/53 "2023-12-31T14:16:30Z")
I assume they were reported by some Apple product, yes. I told my buddy if I was the neighbor, I’d say “It was you that put in that shitty skin track? I’m keeping 'em!” ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [December 31, 2023, 3:57pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/54 "2023-12-31T15:57:33Z")
> [@echoreply](#): > > Yes, sort of. As I mention above, with my Bluetooth only iPad it reports information like “25 feet, NNE,” but is not very accurate. But I assume that’s because an iPad has GPS? Whereas from what I’m reading, it implies the Airtags only have “Hello, anyone? … it’s me!” and let the Apple product doing the receiving figure out its own GPS location as the location “Airtag is nearby this point”? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 31, 2023, 4:44pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/55 "2023-12-31T16:44:31Z")
I think @echoreply was referring to the case where his i-device and his airtag are actively communicating right now. As I rad it, he’s saying the i-device can use something akin to radio direction-finding, signal strength-based range guessing, and its internal compass to develop a _relative_ position between the i-device and the airtag. i.e. the airtag is 25 feet NNE of the i-device. GPS has no role in that. And he’s saying that the relative position-finding process works better / more accurately with UWB than it does with Bluetooth. A separate issue / question is how your i-device’s UI works to lead you to a previously stored GPS location where a non-communicating or out-of-range airtag is presumed to be. Is the UI a map, a computed range and bearing between the I-device’s current GPS coords and the stored GPS coords of the airtag? Does it give “You’re getting warmer / colder” verbal instructions as you walk and turn this way and that, slowly homing in on the stored coords? I don’t know. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 31, 2023, 6:16pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/56 "2023-12-31T18:16:08Z")
> [@LSLGuy](#): > > Is the UI a map, a computed range and bearing between the I-device’s current GPS coords and the stored GPS coords of the airtag? Does it give “You’re getting warmer / colder” verbal instructions as you walk and turn this way and that, slowly homing in on the stored coords? I don’t know. I do not have all the different devices and apps to test, but… you should see a map with your location and the tag’s current or last known location and the distance, and you can click on “Directions” to get specific directions. At some point, if you are close, you can make the tag beep, and you may also see (if you click on “Find”) a big arrow pointing to the tag along with written directions, e.g. “11 ft to your right”. ---
**Author:** ![echoreply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/echoreply/32/3641_2.png) [@echoreply](https://boards.straightdope.com/u/echoreply)\ **Post date:** [December 31, 2023, 6:51pm UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/57 "2023-12-31T18:51:14Z")
> [@LSLGuy](#): > > A separate issue / question is how your i-device’s UI works to lead you to a previously stored GPS location where a non-communicating or out-of-range airtag is presumed to be. > [@DPRK](#): > > you should see a map with your location and the tag’s current or last known location and the distance, and you can click on “Directions” to get specific directions Yes, pretty much exactly that. I’m currently away from home, and have two AirTags near me, and a third at home. On my Bluetooth only ipad I can click “directions” for the nearby AirTags, and it is pretty useless, other than saying we’re all within 100 feet of each other. However on my wife’s iPhone with UWB, I can click “directions” and it does some kind of scanning and then puts up an arrow and range estimate. That did seem very accurate. I had to move around with the phone for a few seconds before it locked on. On both devices, the “directions” for the AirTag that is back at home brought up Apple Maps with driving directions to get there. Apple also reports that AirTag was last seen 3 days ago. At some point someone will go to my house to bring in the mail, and that should give that AirTag a chance to check in with Apple. So the Apple Maps routing seems useful for something like “did I leave my jacket at work or at the restaurant? Take the next left so we can go back,” but a bit silly when it is 800 miles away. If I’m (un)lucky, the airlines will lose my bag on the way home, and I can report what happens when I go to DEN, but my bag goes to DAL. Also, the beeping feature is not very loud. In a quiet house it let me figure out which of the two identical suitcases had the AirTag in it, but in a school, even with the kids all in class, it was absolutely no help in finding the correct instrument case. For malicious intents, there are directions available to disable the beeper, making it difficult for a stalked person to locate the AirTag following them. ---
**Author:** ![Pork\_Rind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pork_rind/32/111_2.png) [@Pork\_Rind](https://boards.straightdope.com/u/Pork_Rind)\ **Post date:** [January 2, 2024, 3:47am UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/58 "2024-01-02T03:47:54Z")
> [@LSLGuy](#): > > As I rad it, he’s saying the i-device can use something akin to radio direction-finding, signal strength-based range guessing, and its internal compass to develop a _relative_ position between the i-device and the airtag. i.e. the airtag is 25 feet NNE of the i-device. GPS has no role in that. And he’s saying that the relative position-finding process works better / more accurately with UWB than it does with Bluetooth. How the UWB location works is through integration of the accelerometers in the iOS device and time of flight measurement of the UWB challenge and response signal. The Find My app knows the distance to the AirTag after measuring the round trip time of a ping, and the app knows how the phone is moving through space from the accelerometers and gyros on board. It only takes a very short period of time for the app to get a ‘fix’ on the AirTag by comparing the motion produced by the user flailing about with the changing measured distance to the tag. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 2, 2024, 3:56am UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/59 "2024-01-02T03:56:58Z")
> [@Pork\_Rind](#): > > How the UWB location works is through integration of the accelerometers in the iOS device and time of flight measurement of the UWB challenge and response signal. Earlier iPhones had real direction-finding via multiple antennas (either 2 or 3, as best I can discern). So in principle, they could do absolute positioning without doing any IMU stuff with the accelerometers. But in the iPhone 14+ there’s only one antenna, and presumably they have to use some kind of warmer-colder system to infer direction. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [January 2, 2024, 5:19am UTC](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317/60 "2024-01-02T05:19:36Z")
I’m sure glad I’m not seeing any advocacy of stalking in this thread. Airtags have definitely been misused for this purpose, and auto mechanics are being trained to spot them. [Previous page](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317.md?page=2) [Next page](https://boards.straightdope.com/t/how-exactly-do-airtags-work/995317.md?page=4)