The scope statement
What our products cannot detect.
This page exists because it is the most useful thing we can tell you, and because a company that only publishes what its products can do has told you almost nothing. Some of the items below are features we built and then removed.
It is also where being a software company shows. We extend what the phone already does — we cannot add a sensor to it. Where its radios stop, we stop. No alert is not a guarantee of safety.
01 — Named plainly
The list.
A microphone that is recording
A phone cannot detect an active microphone. There is no signal to read. We cut the feature rather than ship the theater, and any app claiming otherwise is selling you a light show.
A cell‑site simulator
iOS gives no app access to the baseband radio. Nothing on the App Store can do this honestly, ours included.
A wired or cellular tracker on a vehicle
We find Bluetooth trackers, because they announce themselves. A logger spliced into the wiring and reporting over the cellular network never speaks to your phone.
An AirTag
iOS strips Apple’s manufacturer data out of the advertisement before any third‑party app can see it. QuietCheck cannot detect AirTags and we will not imply otherwise. Your iPhone does this itself, natively and well — that is the tool for that job.
A camera with no radio
A recorder writing to an SD card with its wireless off broadcasts nothing. QuietCheck does offer an optional lens‑glint check that can sometimes catch a lens optically — but it is a heuristic aid, it misses real cameras often, and it flags jewelry and glass. Never treat it as a clearance.
Whether a camera or pair of glasses is actually recording
Recording state is not broadcast. A radio scan can put a device in the room; it cannot put it in the act. On smart glasses the indicator light is the only mechanism designed to tell you that, and it only works when you can see it. The full explanation is here.
A drone that isn’t broadcasting
We read the FAA Remote ID broadcast most drones are required to send. A drone that doesn’t send it is invisible to us.
Anything at all, while it is powered off
Every finding we report starts as a radio signal. No signal, no finding — and the absence of a finding is not evidence of an absence.
No alert is not a guarantee of safety.
If Bluetooth trackers are your specific worry, AirGuard from TU Darmstadt is free, open‑source and good at exactly that. Use it. We would rather you have the right tool than only ours.
02 — The commitment
Why this page exists at all.
Every product we ship gets one of these. It is the first page we write, not the last, and it is a condition of shipping rather than a disclaimer bolted on afterwards.
The reasoning is not modesty. In a category where the product is trust, a limit you published is worth more than a capability you claimed, because the limit is the thing a person can check. A claim only pays off if it holds at the exact moment someone is relying on it, and we would rather be measured on the ones we can keep.
The long version — what a smartphone can and cannot establish about recording devices nearby, and why the difference is physics and platform policy rather than effort — is set out in our reference document. It names the weakest technique in our own product as the weakest technique in our own product.