Technical documentation

How Findy works

Five inspection methods, what each one physically measures, and the conditions under which each one fails. If you only read one page about this app, read this one.

Read this first

None of these methods identifies a hidden camera with certainty. They surface things worth looking at. The final step is always your own eyes on the physical object. An app that tells you it has "confirmed a hidden camera" is telling you something it cannot know.

A. Camera lens-reflection inspection

Camera lenses reflect directed light. When you shine a light at an object and view it from close to the light's axis, a lens can appear as a small, distinctly bright point that shifts as you move. This is the same technique used to spot lenses by eye; the phone camera makes the reflection easier to notice and hold steady.

What limits it

How Findy reports the result

3 reflection(s)

The automatic lens scan reports how many reflective points it is currently tracking and offers an Inspect action. It does not classify any of them.

Hidden camera confirmed

Findy never says this. It cannot classify or validate the device, so any such claim would be false.

B. Infrared-style viewing

Many cameras with night vision illuminate a room using infrared LEDs. That light is invisible to the eye, but some infrared wavelengths reach a phone camera's sensor and appear as a faint white or purple glow on screen. Findy provides a viewing mode intended to make such sources easier to notice in a dark room.

What limits it

Wording we avoid

Findy does not "turn your iPhone into an infrared camera". Your iPhone is not an infrared camera and cannot be made into one in software. Findy provides a viewing mode designed to help you notice light sources that are hard to see unaided. Results depend on your hardware and the room.

C. Wi-Fi and local-network scanning

When you are connected to a Wi-Fi network, other devices on that same network are often reachable. Findy looks at the network you are on and reports what it can observe: which addresses respond, which services they advertise over Bonjour, and which respond on ports commonly used by IP cameras and recorders (RTSP and the vendor control and web ports).

What Findy can observe

What limits it

Device discovered is not camera identified

These are different claims and Findy keeps them separate. A device named IPC-1234 advertising a video service is genuinely worth investigating. A device with no name and no recognisable service is simply unidentified — and most home and hotel networks are full of those.

Findy marks each discovered device either as ordinary or as showing camera-related indicators, and shows the specific reason it was marked. There is no "confirmed" state and no certainty score.

How network results are marked
LabelWhat it means
OrdinaryNothing Findy observed about the device is associated with cameras.
Shows camera-related indicatorsOne of the checks below matched. Findy totals these and reports the count as the number of suspicious devices.

The reason shown beside a marked device is one of the following:

Findy shows the reason behind every flag. Be aware that a device whose name matches a manufacturer known for cameras is flagged on that basis alone — many such manufacturers also make televisions, doorbells and routers, so treat a name-only match as a starting point rather than a finding.

D. Bluetooth discovery

Findy lists Bluetooth Low Energy devices that are advertising nearby, and shows an estimated distance and a direction arrow calculated from the received signal strength. It also watches, in the background, for a device that keeps reappearing near you across different places — the pattern that suggests an item tracker is travelling with you rather than simply being nearby.

Bluetooth discovery finds devices that are

It cannot find devices that are

On distance

Findy estimates a distance and shows a direction arrow, but both are derived from signal strength alone. The estimate comes from a generic path-loss model applied to the received signal level — it is a calculation, not a measurement. Walls, furniture, your own body, the device's orientation and its transmit power all distort it, often severely, so the figure can be wrong by a large margin. Treat it as warmer or colder while you physically move around: the number should fall as you get closer to the source. It is never the device's actual position.

E. Magnetometer checks

The iPhone's magnetometer measures magnetic field strength. Electronics containing motors, speakers, shielding or magnets distort the local field. Sweeping the phone slowly across one specific object, and comparing against a baseline taken away from electronics, can reveal that the object contains more hardware than it appears to.

Important

Magnetic readings are not proof of a camera or microphone. This feature is for investigating a specific physical object — not for sweeping a room automatically. Speakers, motors, chargers, magnets, metal structures, appliances, magnetic phone cases and the building's own wiring all move the needle.

How to take a reading that means something

  1. Remove magnetic phone accessories, cases and stands.
  2. Establish a baseline well away from electronics and metal.
  3. Move slowly around the specific object you are inspecting.
  4. Repeat the measurement to check the reading is stable.
  5. Compare several sides of the object rather than one face.
  6. Inspect the object visually before concluding anything.

Why several methods instead of one button

Each method above fails in a different way. Lens reflection needs the right angle. Infrared needs the camera to actually use infrared. Network scanning needs the device to be on your network and powered on. Bluetooth needs it to be advertising. Magnetometer readings need a specific object to test.

A device that evades one method is often visible to another — and a device that evades all of them exists too. That is why the guided visual checklist matters more than any scan, and why Findy presents its output as evidence to interpret rather than a verdict. One exception we should name: when a device name matches a manufacturer known for cameras, Findy words the reason as "Likely <vendor> camera", which overstates what a name match can actually tell you. We treat that wording as a known weakness rather than a claim you should rely on.

Read the complete limitations · See how we test these claims

Last reviewed 2026-07-23 · Written and reviewed by the Findy developer.