Find My network coverage: what a tag needs to be found

What is Find My network coverage?

It is the density of Apple devices near your item, and nothing else.

A Find My accessory broadcasts a rotating encrypted identifier over Bluetooth Low Energy. Any nearby Apple device that hears it uploads an encrypted note of its own position at that moment. Your Apple Account is the only thing that can decrypt the note. There is no coverage map to consult, because the coverage is wherever people are.

How does a tag get found with no internet of its own?

The passing device supplies the internet; the tag supplies only a signal.

This is why a tag has no SIM, no data plan and no roaming charges, and why a coin cell lasts up to two years. It also explains the shape of the failure: a tag with a perfectly good battery in a building with nobody in it is invisible, not broken.

Which places have good coverage and which do not?

Anywhere with a crowd is excellent; anywhere without one is a guess.

What is the range of the tag itself?

Up to 60 m / 200 ft between your own phone and the tag, before the network takes over.

That figure is line of sight in the open. A suitcase full of clothes, a car boot, a wall or a metal locker all cut it, sometimes by half. Within that range you can also make the tag sound at 80–100 dB, which is the part of finding things that a map cannot do.

How often does the position update?

Whenever somebody passes, which is as often as the place is busy.

There is no update interval to set. A bag on a carousel may refresh several times a minute; the same bag in a locked store at 4am may not refresh until the first shift arrives. Because of that, the timestamp next to a position is as important as the position: a six-hour-old pin in a warehouse is usually correct and simply means the warehouse was empty.

How many devices does it take to find something?

One is enough, and one is often all there is.

People assume the network needs a crowd to work. It does not: a single phone in a passing pocket produces a sighting, and a sighting is a position and a time. A crowd only changes how often the position refreshes. That is why a tag in a quiet village still reports once or twice a day, and why the difference between a busy setting and a quiet one is measured in freshness rather than in whether the thing can be found at all.

Does anyone else see where my things are?

No, and the relay is anonymous in both directions.

The device that reports your tag learns nothing about you or the item, and you learn nothing about the device that reported it. The sighting is encrypted before it leaves that phone, and only your Apple Account holds the key. Apple cannot read it, we cannot read it, and the manufacturer cannot read it. Apple's unwanted-tracking alerts sit on top of this, so a tag travelling with a person who does not own it will warn them, which is the intended behaviour rather than a flaw.

What breaks coverage entirely?

Metal, distance from people, and being switched off.

Sealed metal containers attenuate Bluetooth badly, which is why bags rarely report from inside a loaded freight container. Beyond that, the failure modes are prosaic: a flat coin cell, a tag left out of the bag, or an item that never went where you thought. None of these are network problems, and all of them look like one.

How Locata Tag uses the network

The Locata Tag carries an MFi certified chip, which means it is found by precisely the mechanism described above, no servers of ours are involved at any point, and there is nothing to log into. It registers as an Other Item in Apple's Find My app, on iPhones and iPads from iOS 14.5 onwards, beside Apple's own accessories.

Two design choices follow from how the network behaves. The speaker is loud, at 80–100 dB, because sound is the only tool for the last few metres when there is no Ultra Wideband and therefore no Precision Finding arrow. And the battery is a user-replaceable CR2032 running up to two years, because a tag that needs charging is a tag that is dead in exactly the quiet places where coverage is already poor.

The sealing is IP67 and the tag is 36.3 × 36.3 × 9 mm, around 10 g, so it can live in a suitcase lining or a bike bag permanently. It is iPhone and iPad only; there is no Android version and there will not be one.

Boxes hold two tags and two key rings. see what that costs.