How a Find My tracker finds things with no internet

What is actually inside a Find My tracker

Very little, and that is rather the point. Take the back off one and you find a coin cell, a small speaker, an antenna printed onto the circuit board, and a secure chip. No satellite receiver. No modem. Nothing that reaches for a mobile mast. The whole assembly is 36.3 mm square, 9 mm thick and weighs about ten grams.

What it does have is a Bluetooth Low Energy radio, and BLE was designed for precisely this job: say one very short thing, very quietly, over and over, for years, on a battery you could post in an envelope.

The short thing it says is a public key. Not a name, not a serial number, not your Apple Account a cryptographic key that rotates on a schedule, so the same tag looks like a different anonymous stranger to anybody who sits in a car park logging Bluetooth traffic all day. The tag does not know where it is. It has never known where it is, and it has no way of finding out.

The relay, step by step

Four things happen, and only the first one involves your property.

The tag speaks into the dark

Every few seconds the tag broadcasts its current rotating key. That advertisement travels up to about 60 m in open air, considerably less through a suitcase shell, a car boot lid or a brick wall. Nobody has to be listening. It broadcasts anyway.

Somebody else's iPhone overhears it

Any nearby Apple device running in the background, a stranger's iPhone in the taxi queue, an iPad in a hotel lobby, a Mac on a desk by a window, picks up that advertisement. Their device checks its own location, encrypts that location using the key it just overheard, and quietly uploads the result. Their phone never tells them it did this. It cannot tell them what it found, because it does not know either.

Apple stores something it cannot read

What arrives on Apple's servers is a sealed envelope filed under an index that means nothing on its own. Apple holds the ciphertext. Apple does not hold the key that opens it, so it cannot look inside any more than the passing stranger could.

Your iPhone opens the envelope

The private key that decrypts those reports exists in one place: the devices signed in to your Apple Account. When you open Find My and tap your item, your own phone fetches the sealed reports, unseals them locally, and draws the pin. The location you are looking at was worked out on your handset a second ago, by you, from data nobody else in the chain could read.

That is why the honest description of a Find My tracker is not "it phones home". It never phones anybody. Other people's phones do the phoning, blindly, on its behalf.

Why the word "offline" is misleading

People often ask whether a tag works offline. The truthful answer is that the tag is never online in the first place, not once, not for a second. It has no connection to lose.

What varies is not the tag's connectivity but the density of other people's Apple devices around it. That has some practical consequences worth planning for:

• Busy places update constantly. An airport concourse, a city centre, a motorway service station, a train, a tag in any of those is being overheard by dozens of handsets an hour, so the map keeps pace with reality.
• Empty places go quiet. A Highland bothy, a farm track, a storage yard at 3 a.m. The tag is still shouting; there is simply nobody in earshot to relay it.
• Metal and depth blunt it. An aircraft hold, a shipping container, the boot of a car in an underground car park. Bluetooth is a low-power radio and steel is very good at stopping it.

This is the single most important habit to build: read the timestamp, not just the pin. Find My tells you when a location was last confirmed. "Now" and "3 hours ago" mean two completely different things, and only one of them is worth getting in the car for.

What the network can and cannot do for you

It can tell you which building your bag reached. It can tell you the bag left the airport on a van. It can tell you your keys are somewhere in the house rather than somewhere in the pub. It can hold a message and a contact route for a stranger who picks your holdall up, without ever handing them your phone number.

It cannot give you a live, second-by-second trail like a vehicle tracker. It cannot point an arrow at the exact drawer, there is no Ultra Wideband radio in a tag at this end of the market, so Precision Finding is not part of the deal. And it cannot help an Android phone at all: this is Apple's network, reachable only from an iPhone or iPad on iOS 14.5 or later.

Once you are close, the map hands over to your ears. That is what the speaker is for.

How the Locata Tag fits into all this

The Locata Tag is one of those anonymous shouting devices, built to Apple's MFi specification so it registers in Find My as an item of your own alongside your phone and your AirPods. There is no separate app to install, no account to create and no subscription waiting for you in a year's time the relay described above is Apple's, and using it costs nothing.

Within earshot, tap Play Sound and the tag answers at 80–100 dB from as much as 60 m away, which is what actually gets you from "the right room" to "the right cushion". Turn on Notify When Left Behind and your iPhone speaks up as you walk away, while turning round is still a short walk. Mark it lost and a finder can reach you without learning anything about you.

It is IP67 rated, so rain and a spilled bottle are non-events, and the CR2032 inside runs for up to two years before you twist the back off and drop in a replacement from any supermarket. Boxes hold two tags and two key rings, which is generally one for the thing that travels and one for the thing that hides. If you want the specifications side by side, the full answers are on our FAQ page.

Two tags, free UK delivery, and a network that is already in your pocket. see what a box costs.