Google's connected home devices and services rely on cameras, microphones and other sensors to provide helpful features and services. These sensors can detect things like motion and sound to protect your home and loved ones and make your lives more convenient and comfortable. And while they make our connected home devices more useful, we understand that you, your family and your friends need to trust that we'll handle your data responsibly.
We've published our commitment to privacy in the home where we've committed to the following:
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When our connected home devices include cameras, microphones, or environmental or activity sensors that detect information about your home environment, we'll list these hardware features in the device's technical specifications — whether or not they're enabled.
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We'll also more clearly explain what types of information these sensors send to Google, as well as examples of how we use that information, to help you better understand their purpose.
We have published this sensors guide as part of these commitments. We will continue to periodically update this sensors guide to add new devices, features and services, reflect changes to our existing offerings, or where applicable, provide additional details and information.
The current sensors in Google's connected home devices and services generally fall into the following categories:
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Cameras that record video footage and still images and detect what's happening in the home.
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Microphones that record audio and can detect specific sounds or motion nearby.
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Activity sensors that detect activity or changes to the physical state of the device, such as a door sensor that detects when a door opens, or an accelerometer that detects when a device is moved. Some activity sensors may also detect the presence or movement of people in your home.
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Environmental sensors that determine external properties of the surrounding environment — such as temperature, humidity, light, or smoke — and that can help monitor the conditions inside or around your home.
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Control sensors that enable control of a device, such as a touch-sensitive button, or a magnetic sensor to detect the position of the ring on the Nest Learning Thermostat.
Google's connected home devices may also contain additional sensors that monitor device operation. For example, internal device sensors can detect when a device's battery is running low, when it's overheating, or other conditions that can affect the ability of the device to operate as intended. We've excluded sensors that collect only such diagnostic data from this sensors guide. In addition to enabling the features and services described, the data from the sensors listed below may also be used to perform device performance and diagnostic functions.
Types of sensors, what they measure, and examples of uses
Type of Sensor |
What it Measures |
Examples of Uses* |
|---|---|---|
Cameras and Microphones |
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Camera (lens and image sensor) |
Cameras are used to capture still images and video footage for a variety of purposes, which include home monitoring, video calling, and more. They can also be used as a sensor to detect things like motion, activity, people or gestures. Cameras can also be used as a biometric sensor to identify a specific person. |
Nest Cam, Nest Cam IQ, Nest Cam (battery), Nest Cam with floodlight, Nest Cam (indoor, wired), Nest Doorbell (wired)/Nest Hello, Nest Doorbell (wired, 2nd gen), Nest Doorbell (battery), and Nest Hub Max Checks what's happening near the camera. Also used to detect certain types of activity, so you get an alert when a person or motion is detected near the camera. Depending on the camera model, where you live, and whether or not you have a Nest Aware subscription, the camera can be used to identify a face you've told it to recognize and send an alert when it recognizes someone you know or a stranger. Camera events can be used to start home automations. Nest Hub Max In addition to the built-in Nest Cam features described above, Nest Hub Max also uses the camera to enable video calling, personalization with Face Match, and Quick Gestures for easy device control. Additional features that use the camera may be added over time. |
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Microphone |
Microphones detect sound waves and are used for a variety of purposes in Nest devices, including to capture speech, and as a sensor to detect specific sounds or to detect motion nearby. |
Nest Cam, Nest Cam IQ, Nest Cam (battery), Nest Cam with floodlight, Nest Cam (indoor, wired), Nest Doorbell (wired)/Nest Hello, Nest Doorbell (wired, 2nd gen), and Google Nest Doorbell (battery) Hears what's happening near the camera. Also used to detect certain types of sounds so you can get an alert when a person or motion is detected near the camera. The microphone is also used for the Talk and Listen feature that lets you talk to anyone near the camera. Nest Cam IQ Indoor also allows you to talk to the Google Assistant (if you have enabled that feature). Google Home, Google Home Mini, Google Home Max, Google Nest Hub, Google Nest Hub (2nd gen), Google Nest Hub Max, Google Nest Mini, and Google Nest Audio Allows you to talk to the Google Assistant, make calls, and with a Nest Aware subscription in certain regions, detect sounds like smoke alarms or glass breaking (if you have enabled that feature). Provide occupancy signals for home automation (such as Home & Away Routines), if you've enabled the feature. Google Nest Wifi point Allows you to talk to the Google Assistant, navigate apps on your TV, and provide voice input to apps. Nest Protect Used by the Sound Check and Safety Checkup features to make sure the speaker and alarm sound are operational. The microphone is not used for any other purpose and is off except when checking speaker and horn functionality. Nest Hub, Nest Hub (2nd gen), Nest Hub Max, Nest Mini, and Nest Wifi point Emits ultrasonic pulses from the speaker to detect proximity of a user for a more responsive and proactive device experience, such as triggering the display of media or device controls on the device. Nest Hub (2nd gen) When Sleep Sensing is enabled, listens for nearby sounds such as coughing and snoring that may disturb sleep. |
Activity Sensors |
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Accelerometer |
Accelerometers measure movement of a device. They are commonly used to change the device state, facilitate pairing with other devices, detect changes in orientation and adjust the device's display layout, or to detect tampering (i.e., if a device is moved when it isn't expected to move). |
Google Home Max Adjust lights depending on speaker orientation. Detects the motion of the remote to initiate reconnecting with paired devices and facilitate interactions with other devices. Nest Connect and Nest Protect Currently unused. Included for potential future feature enhancements. |
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Motion |
Motion sensors detect movement of people or animals in a room. |
Nest Cam (battery), Nest Cam with floodlight, and Nest Doorbell (battery) Detects motion to wake up the device. Nest Cam with floodlight Detects motion to trigger the lights. Nest Learning Thermostat and Nest Thermostat E Nest may infer occupancy from detected motion for comfort optimization, energy saving, and home automation (such as Home/Away Assist or Home & Away Routines). Nest Protect Detects motion for home automation (such as Home/Away Assist or Home & Away Routines) and to turn on Pathlight when someone walks under Nest Protect. All of the above devices where motion is detected Detects motion to trigger home automations |
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Proximity |
Proximity sensors detect the presence of nearby objects. |
Nest Learning Thermostat Detects motion near the thermostat in order to light up the display. |
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Ultrasonic |
Ultrasonic sensors use sound waves to measure distance to an object and can be used to detect when someone is near a device. |
Nest Protect (1st generation) Currently inactive. |
| Bluetooth | Bluetooth can be used for set up and to detect the presence of other Bluetooth-enabled devices. It can also be used to stream audio from one device to another. | |
| Soli Sensor | The Soli sensor can be used to detect motion, proximity and presence of nearby objects. Learn more. |
Nest Learning Thermostat (4th gen) and Nest Thermostat and Nest Thermostat Detects activity near the thermostat to light up the display. Nest thermostat technical specifications Google Home, Google Home Mini, Google Nest Mini, Google Home Max, Google Nest Audio, Google Nest Hub, Google Nest Hub (2nd gen), Google Nest Hub Max, Google Nest Wifi point, Chromecast with Google TV, Google Chromecast Voice Remote, Google TV Streamer (4K), Google TV Streamer Voice Remote, Nest Temperature Sensor, Nest Learning Thermostat, Nest Thermostat E, Nest Thermostat, Nest Cam (battery), Nest Cam with floodlight, Nest Cam (indoor, wired), Nest Doorbell (battery), Nest Doorbell (wired, 1st gen), and Nest Doorbell (wired, 2nd gen) Detects the presence of a device tag on another compatible Bluetooth-enabled device (such as letting you use Tile with your Google Home smart speaker) to setup and enable various built-in features. Nest Temperature Sensor, Nest Learning Thermostat, and Nest Thermostat E Allows Nest Temperature Sensor to use Bluetooth to communicate with your thermostat. Google Home, Google Home Mini, Google Nest Mini, Google Home Max, Google Nest Audio, Google Nest Hub, Google Nest Hub (2nd gen), Google Nest Hub Max, Google Nest Wifi point, Chromecast with Google TV, Google Chromecast Voice Remote, Google TV Streamer (4K), and Google TV Streamer Voice Remote
Nest Learning Thermostat (4th gen) and Nest Thermostat Detects activity near the thermostat to light up the display. Nest thermostat technical specifications Nest Hub (2nd gen) Detects movement and breathing which allows you to use Sleep Sensing. Detects movement so you can control media, alarms and timers using Quick Gestures. Detects occupancy for home automation (such as Home & Away Routines), if you've enabled that feature. |
Environmental Sensors |
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Ambient Light Sensor |
Ambient light sensors measure the amount of light in a room. |
Google Home and Google Home Max Controls LED brightness. Nest Hub, Nest Hub (2nd gen), Nest Hub Max Controls display brightness and color calibration. Nest Hub (2nd gen) Measures ambient room light with Sleep Sensing to help you understand sleep environmental disturbances. Nest Learning Thermostat, Nest Thermostat E, and Nest Thermostat Controls display brightness and improve temperature sensor accuracy by detecting when the sun is shining on the thermostat. Nest Cam IQ and Nest Doorbell (wired)/Nest Hello Detects day or night to switch Night Vision off and on. Nest Cam with floodlight Detects day or night to trigger the lights only at dark. Nest Protect Detects when the room is dark so it can automatically turn on the Pathlight and Nightly Promise features. |
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Carbon Monoxide |
Carbon monoxide sensors measure the amount of carbon monoxide in the air. |
Nest Protect Detects dangerous levels of carbon monoxide in the air. |
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Humidity |
Humidity sensors measure the amount of water (relative humidity) in the air. |
Nest Learning Thermostat, Nest Thermostat E, and Nest Thermostat Detects ambient humidity for comfort optimization and control of whole-home humidifiers. Nest Protect Enables the Steam Check feature to reduce nuisance alarms caused by things like steam from your shower. |
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Smoke (photoelectric sensor) |
Detects the presence of smoke in the air by sensing when smoke particles pass in front of an infrared light source. |
Nest Protect (1st generation) Fire or smoke detection. |
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Smoke (Split-Spectrum sensor) |
Detects the presence of smoke in the air using 2 wavelengths of light to search for smoke. An infrared light is used to detect larger particles generated by slow, smoldering fires, while a blue light detects smaller particles created by fast fires. |
Nest Protect (2nd generation) Fire or smoke detection. |
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Temperature |
Temperature sensors determine the current temperature. This can be the ambient temperature in a room, or the temperature inside a device. |
Nest Hub (2nd gen) Measures ambient room temperature with Sleep Sensing to help you understand sleep environmental disturbances. Nest Learning Thermostat, Nest Thermostat E, Nest Heat Link E, Nest Temperature Sensor, Nest Thermostat Estimates ambient room temperature for comfort optimization. Nest Protect Detects sudden rises in room temperature. |
Control Sensors |
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Capacitive Touch |
Detects the position and motion of a person's finger on the surface of a display or button. |
Google Home, Google Home Mini, Google Nest Mini, Google Home Max, Nest Hub, Nest Hub (2nd gen), Nest Hub Max, Google Nest Audio, and Nest Thermostat Used for device control and provides an occupancy signal for home automation (such as Home & Away Routines), if you've enabled that feature. Google Nest Wifi point Used for device control. |
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Magnetometer |
Magnetometers (also commonly referred to as magnetic sensors) measure the strength of and changes to a magnetic field. When used for device control, a magnetometer can detect the position of an object based on changes to the magnetic field when the object is moved. |
Nest Learning Thermostat (4th gen), Nest Learning Thermostat (3rd generation) and Thermostat E Detects movement of the ring for manual thermostat control. Nest Cam (battery), Nest Cam with floodlight, and Nest Doorbell (battery) Detects tampering of the device. Detect when the device is being charged to disable the camera. |
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Optical |
Optical sensors measure changes to the amount of light shining on the sensor. Optical sensors can detect the position of an object by sensing whether the object is blocking a beam of light. |
Nest Learning Thermostat (1st gen and 2nd gen) Detects movement of the ring for manual thermostat control. Nest ✕ Yale Lock Detects whether the bolt is open or closed. |
* This is a non-exhaustive list of examples of how sensors explained here are used in Google's connected home devices and services. Our goal is to help you better understand the purpose behind these sensors, and the different ways these sensors are used in our devices and services to offer helpful features and services.