Can a Security Camera See Through a Window?

The short answer

Yes by day, mostly no by night, and it depends on the camera in a way the box does not tell you. There are two separate problems with a camera behind glass, and they have different fixes. The first is light: at night the camera illuminates the scene with infrared LEDs, and glass throws that light straight back into the lens. The second is detection: battery cameras notice motion by sensing body heat, and heat does not pass through a modern window. A camera that has both problems — a battery camera with infrared — is useless behind glass after dark. A plug-in camera with a sensitive sensor and its infrared switched off is a workable window camera, provided there is some light outside.

Everything below is drawn from the camera makers’ own support pages, read on the date at the top of this page. Ring, Arlo, TP-Link, Wyze and Blink all address the window question directly, and they agree with each other to a degree that is unusual in this industry. We have not tested cameras behind glass ourselves; here is what we do instead.

Problem one: the camera lights itself up

Night vision is not a more sensitive eye; it is a flashlight you cannot see. When the light drops, a camera switches on infrared LEDs — Blink describes an 850nm infrared LED that shows “clear video in areas of complete darkness,” and Ring describes switching “to sharp black and white infrared imaging” when the scene goes fully dark. Point that at a window and the pane acts as a mirror for part of the beam. What you get in the footage is a white bloom, a ghost image of the camera, or a picture so washed out the street disappears.

The makers are blunt about it. TP-Link: “If the camera is installed behind glass, infrared lights may cause reflection when the camera works in the Night mode, resulting in blurry and unclear images.” Ring: “Positioning your camera to face a window, screen, or other transparent barrier can cause issues with motion detection and video quality.” Blink: “Placing your camera on a deep ledge or beside any reflective surface can result in glare that can impact image quality.” Wyze went as far as designing a separate camera for the job and explains why: it “removed the IR lights and the spotlight entirely to reduce glare and reflections that cause poor image quality at night.”

The fix follows from the cause: turn the infrared off. Ring says as much — “if your camera is facing a window, the infrared light can be turned off to avoid lights reflecting back into the camera.” Wyze’s support pages document a Night Vision IR Lights toggle in its app, with the caveat that visibility with the LEDs off depends on the light available. TP-Link’s advice for keeping the IR LEDs off at night is to set the camera to Day mode. With the LEDs off, the camera can only see what the outside world lights for it: a porch light, a streetlamp, a neighbor’s floodlight. That is where the sensor matters.

Problem two: battery cameras cannot feel heat through glass

A battery camera spends most of its life asleep, waiting for a passive infrared sensor — a heat detector — to wake it. That is what gives it months of battery life, and it is why it fails behind a window. TP-Link’s positioning guide is categorical: “Do not place the camera behind glasses (such as windows) since glasses will block the motion sensor of the battery camera, making it unable to detect motions.” Arlo explains the mechanism — “some motion detection technology works by detecting changes in heat. Most glass used in homes today is insulated, limiting the movement of heat through windows” — and adds that “moving reflections in glass surfaces can trigger false motion detection.”

So a battery camera behind glass does two wrong things at once: it misses the person walking up the path, and it wakes for the headlights sweeping across the pane. No setting fixes that, because the sensor is physical. This rules out every battery camera we cover for window duty — the eufyCam, the Reolink Argus, the Blink Outdoor 4, Ring’s battery Outdoor Cam, the Arlo Pro — however good they are on a wall. Our wired vs wireless guide covers the detection difference in full.

A plug-in camera is always awake, so it can watch the image itself for change rather than waiting for heat. TP-Link’s own caveat applies: reflections on the glass can still blur the image and confuse detection, especially at night, so expect more false alerts from a window camera than from the same camera outside. During the day, with the glass clean, it works.

The setup that does work

If you cannot mount outside — a rental, an upper floor, a wall you cannot drill — here is the arrangement the makers’ guidance adds up to.

Two more things. Turn any built-in spotlight off as well — it reflects exactly as infrared does, which is why Wyze removed both from its window camera. And keep expectations honest: a window camera with its infrared off sees what a person standing at that window would see. On a lit street, that is plenty. In a dark yard, it is very little, and the right answer is a light outside or a camera outside.

The two cameras we would put in a window

Both are plug-in, both publish a starlight-type sensor with full-color low-light video, both let you switch the infrared off, and both record to a memory card with no plan — which matters, because a window camera is often the only camera a renter has. TP-Link publishes a 1/2.9” progressive-scan CMOS starlight sensor with full-color night vision, 2K QHD resolution, a 120-degree diagonal view and a microSD slot up to 512GB for the Tapo C120. Wyze publishes a CMOS starlight sensor with color night vision, 2.5K resolution, a 115.8-degree diagonal view and a microSD slot up to 256GB for the Cam v4, and its support pages document the IR-light toggle. Neither is designed specifically for glass — Wyze sells a separate camera for that — but both have the two features that make glass workable.

Choosing between them is our Wyze vs Tapo comparison; both also appear in the indoor camera ranking. If the window in question is beside the front door, a video doorbell mounted outside is usually the better answer, and do video doorbells need existing wiring? covers whether yours can take one.

If you can mount outside, do

Every maker’s guidance ends the same way. TP-Link: a camera “should always be placed with an unobstructed view,” and an outdoor area is best covered by an outdoor-rated camera mounted outside. Ring’s positioning guide gives the height — outdoor cameras 8 to 10 feet up with a 20-degree tilt. The two cameras above are both outdoor-rated, IP66 for the Tapo and IP65 for the Wyze with its outdoor power adapter, so the window camera you buy today can move under the eave the day you are allowed to drill. Our placement guide covers the rest, including the privacy lines around what a camera pointed at the street may record of your neighbors — which apply just as much from behind a window as from a wall.