Nearly every feature in item tracking is a cure: the thing is lost, and the tracker helps you find it. Separation alerts are the exception. They are the one feature that stops the loss happening, and most people who own a tag have never switched them on.
What they do
Your phone keeps a rough sense of where you and your tagged items are. When you leave a place and a tagged item does not come with you, it tells you — ideally while you are still in the car park rather than at bedtime.
For keys, a wallet, a laptop bag or a passport, that is more valuable than any map, because the common failure in this category is not mislaying something at home. It is leaving it behind somewhere else.
How it works on each platform
Apple Find My. The most mature implementation, free, with no paid tier. Enabled per item, and it works for AirTags and third-party Find My accessories alike.
Google Find Hub. Equivalent functionality on Android for Find Hub devices, also free.
Samsung SmartThings Find. Same idea for SmartTags on Galaxy devices.
Tile. Tile calls these Smart Alerts and they sit behind a Life360 membership, published at $9.99, $16.99 and $24.99 a month. This is worth knowing because Smart Alerts are the feature in most Tile advertising, and on every other platform the equivalent is free.
The setup step everyone skips
Trusted locations. This single step decides whether you still have the feature enabled in a month.
Here is the failure sequence. You enable separation alerts. You leave the house without your spare keys, which live in a drawer, and get an alert. You go to work and leave your bike lock at home, and get an alert. By Thursday you have had six notifications about items you deliberately left behind, and you switch the feature off.
The fix is to mark the places where leaving an item is normal — home, work, a regular gym — as trusted, so no alert fires there. Do it during setup, before the annoyance accumulates.
A related point: enable alerts per item rather than for everything. Keys, wallet and laptop bag, yes. The tag on the spare car key that lives in a drawer, no.
What they are genuinely good at
Restaurants, taxis and bars. The classic wallet-and-phone-on-the-table scenario. An alert as you leave is worth more than knowing an hour later which restaurant it was.
Offices and co-working spaces. A laptop bag left under a desk, noticed in the lobby rather than at home.
Gyms and pools. The locker-room scenario, where things get put on a bench and left.
Travel. A bag left in a hotel room, a hire car, or at a departure gate. For a traveler this is the most valuable application of the whole category.
The honest limitations
They are not instant. The system needs to be confident you have actually left rather than walked to the far side of a building, so there is a lag — usually a few minutes. Enough to turn round in a car park; not enough to catch you on the way out of the door.
They depend on your phone. Flat phone, no alert. Phone left behind along with the keys, no alert.
They can miss in dense indoor environments. A large building where you move between floors can confuse the heuristic in both directions.
They are not a security feature. An item taken from you deliberately is a different problem, and the alert may arrive long after it matters.
How to set it up well, in four steps
1. Enable separation alerts for the three or four items you genuinely carry every day. Not everything you own a tag for.
2. Add home, work and any regular venue as trusted locations in the same sitting.
3. Live with it for a week and add any further trusted location that generates a nuisance alert, rather than switching the feature off.
4. Re-check it after a house move or a job change, because your trusted locations are now wrong and the nuisance alerts will start again.
The habits that pair with this do more than any feature, and together they are most of the problem solved.
