Bluetooth trackers are everywhere. AirTag, Tile, Samsung SmartTag — the market is full of small, cheap devices you can slip into a bag or attach to your keys. They're marketed as the solution to lost items. But there's a fundamental limitation baked into every one of them — and understanding it explains exactly why people find their tracker useless the one time they actually need it.
Every one of these trackers uses Bluetooth Low Energy (BLE) — a version of Bluetooth designed for devices that need to run for months on a coin cell battery. The tradeoff for that efficiency is range and data throughput. A BLE device broadcasting at typical power levels can be detected from roughly 10 to 30 metres — though walls, interference, and real-world conditions shrink that significantly.
BLE devices communicate through advertising packets: small bursts of data broadcast on a repeating schedule. Your tracker sends these packets every few hundred milliseconds. Any nearby device with Bluetooth scanning enabled — a phone, a tablet, a laptop — can pick them up.
Your phone is always doing this in the background. When it sees your tracker's advertising packet, it records the signal and knows the tracker is close. That's the whole system when you're nearby: your phone sees the packet, logs the location. Simple.
The problem begins the moment the tracker leaves your Bluetooth range. If your bag is left in a hotel room and you've checked out, your phone can't see it. If your luggage goes to the wrong city, you can't ping it. The tracker is still broadcasting — but there's nothing listening.
This is where crowd networks come in. Apple's Find My, Tile's network, and Samsung's SmartThings Find all work on the same principle:
No single participant can see whose tracker it is or that they've relayed anything. The encryption is real and the anonymisation is genuine. It's a clever system.
The crowd network model works in two scenarios: dense urban environments where millions of compatible devices are constantly moving around, and situations where your item is mislaid rather than truly lost. For everything else, it breaks down in predictable ways.
Apple has the largest crowd network by a significant margin — hundreds of millions of iPhones continuously scanning in the background. In Manhattan, London, or Tokyo, there's a very real chance someone walks past your tracker within minutes of it being left somewhere. In a rural area, a parking lot at night, or any location with sparse foot traffic, your tracker could sit for hours — or days — without a single update.
When you open your tracker app and look for a location, you're not pinging the device. You're seeing the most recent crowd network sighting — which could be from ten minutes ago or ten hours ago. There's no way to ask your tracker "where are you right now?" because it has no internet connection. It can only be found if someone else happened to walk by.
Theft tends to happen fast. A bag snatched and put in a car can travel 60 km/h. The window during which a crowd network might catch a location update — between the theft and the tracker leaving populated areas — is exactly when you most need real-time data. A stale location from thirty minutes ago tells you very little.
AirTag notifies nearby iPhones if an unknown AirTag has been travelling with them for a while. This is a legitimate and important anti-stalking measure. But it also means a thief with an iPhone will receive an alert, know there's a tracker in the bag, and dispose of it. The privacy protection that makes these devices trustworthy also makes them easier to defeat.
The phrase you'll see in every Bluetooth tracker's marketing — "last known location" — deserves scrutiny. It means: the last place a stranger's phone happened to pick up your tracker's signal. In a busy city, that might be accurate to a few minutes. In a suburb at 2am, it could be the location from before you left the house yesterday morning.
When you're standing in the right neighbourhood with your phone open, Bluetooth proximity works well. The device shows "nearby," you make it ring, you find your keys. That's the use case these trackers were genuinely designed for — and they handle it well.
The failure mode isn't the technology being broken. It's the technology being sold as something it isn't: a way to find things that are truly gone.
The only way around the crowd network limitation is to give the tracker its own independent connection to the internet. That means either GPS (so it knows its own coordinates) plus cellular (so it can transmit them), or some combination of the two.
A device with GPS and LTE doesn't depend on strangers. It knows where it is. It can tell you. You can ask it — right now — and it responds. The tradeoff is battery life and cost: GPS and cellular radios use significantly more power than BLE, and they require an active cellular plan.
But for the scenarios where tracking actually matters — theft, loss in unfamiliar places, luggage that goes to the wrong destination — independent connectivity isn't a premium feature. It's the minimum viable capability.
Understanding what Bluetooth trackers actually do makes their limitations obvious — and makes it clear why a fundamentally different hardware approach is the only real solution for situations where the item is truly gone. The next article covers how GPS and LTE work, and why the battery tradeoffs are more manageable than you might expect.
Ankhora uses GPS + LTE to find your things anywhere, independently — no crowd network required. Join the founding member waitlist.