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Learn about Nest Detect and how it works

Google Nest Detect is an advanced sensor that can detect motion and when windows and doors open or close. It can even tell when it’s being tampered with. Detect requires Google Nest Guard to sound the alarm and work with the Nest app.

Detect also has convenient features like Pathlight which automatically lights your way in the dark. But first, let’s cover some key points about setup and installation: how and where you choose to install Detect will change what it will look out for. 

Where you can place Nest Detects 

When you’re first setting up a Nest Detect, the app will ask you whether you want to install your Detect on a door, window or wall. It will sense different things depending on where you’re going to install it.

Here’s a table showing what Detect can look for in each type of spot:


detect on door image

detect on window image

detect on wall image


On a door

On a window

On a wall


Nest Detect can
sense when a door
opens or closes, or
when someone walks nearby

Nest Detect can
sense when a
window opens or

Nest Detect can
sense when someone walks nearby

Detects motion
in a room or hallway

check mark icon


check mark icon

Detects open-close
(requires open-close magnet, included)

check mark icon

check mark icon


How the security level affects what Detects sense 

Google Nest Secure has three different security levels that you can use when you’re home or away. Your Detects will look for different activities depending on what level is currently set. For complete details, see the following article.

Learn about Nest Secure alarm levels: Home and Guarding, Away and Guarding, and Off >

How open/close detection works 

Nest Detect senses that a door or window is open or closed by measuring the magnetic force from the open/close magnet. When Nest Secure is armed, and Detect senses it has moved away from the magnet, the alarm will sound and you’ll get a notification sent to your phone. Depending on the mode it’s armed in, you may get a spoken Heads-Up alert from Nest Guard before the alarm sounds.

How motion detection works 

Motion detection is enabled by default when Nest Secure is set to Away and Guarding. You can also enable motion detection on Detects when Nest Secure is set to Home and Guarding. When a person enters the Detect’s range (about 15 feet or 4.5 m), both their motion and body heat can trigger an alarm. The illustration below shows Detect’s motion detection range.

detection motion side image

detect motion top image

Side view

Top view

Additional Detect features 

We decided to make Nest Detect more than just a sensor, so we gave it features that make it easy for everyone in your home to use.

Quiet Open

If you just want to let some fresh air in while Nest Secure is armed, simply press the button on a Detect to turn on Quiet Open. Then you can open that door or window without sounding the alarm.

Reduced Motion Sensitivity

Reduced Motion Sensitivity will let you set your Detects and Guard to help reduce false alarms caused by your dog (under 40 pounds or 18 kg) or other things in your home. You’ll need to place Detects at a different height than your would for a standard installation (exactly 6 feet 4 inches above the floor), and you’ll need to turn on Reduced Motion Sensitivity with the app. Doing this will slightly reduce all your Detects’ range.

detect reduced side image

detect reduced image

Side view

Top view


Tamper Detection

Nest Detect can also sense if it’s been tampered with. If it’s removed from the backplate while Nest Secure is armed, the alarm will sound. The Nest app can also send you a tampering notification so you can stay on top of your home’s security even when you’re not there.


Pathlight is designed to help you every day. It’s a night light that automatically turns on when you walk by, so you don’t need to stumble around in the dark. It’s ideal for hallways, the kid’s room or any location in your home where you’d like a bit of extra light.

Light Ring

Nest Detect’s light ring can also tell you what’s happening. Press a Detect’s button to check its status. If it’s green, go ahead and open the window: the alarm won’t sound. If it’s yellow, something needs your attention

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