1. Redefining the smoke and carbon monoxide alarm.

    We believe a smoke alarm should do more than chirp, blink or yell at you. So we created Nest Protect. It required new thinking. New sensors. New algorithms. We couldn’t just tweak, we had to invent. And it required testing. And more testing. And even more testing. And it was worth it. Because we changed what a smoke alarm can be.

    Go inside

  2. A light that does more than blink at you.

    The Nest Protect ring gives you more information than you’re used to getting from a smoke alarm. It will glow yellow if there’s a potential problem, red in an emergency or green to show you the batteries and sensors are working.

  3. Designed with air in mind.

    Airflow is key to a smoke alarm. And the right amount of air means better detection. We designed Nest Protect so air comes in through the side vents and flows along interior channels that guide it toward the sensor.

  4. Smoke chamber & sensor

    Fire is unpredictable. The smoke chamber is designed to draw air from any direction to the photoelectric sensor inside.

    Heat sensor

    Where there’s a quickly rising temperature, there’s often fire. If Nest Protect senses a quick rise in temperature, it becomes more sensitive to smoke. You get an earlier alert, and more time, to handle an emergency.

  5. Carbon monoxide sensor

    Carbon monoxide (CO) is odorless, colourless, and can be deadly. When the sensor detects dangerous levels of CO, it immediately triggers an alert. Confusion is a symptom of CO poisoning, so Nest Protect tells you what you need to do.

    Activity sensors

    Three activity sensors let Nest Protect know you’re there so that it can turn on its light as you walk by at night. Nest Protect can also tell your Nest Thermostat that there's nobody home, to improve Auto-Away.

  6. Light sensor and ring

    When you turn out the lights, Nest Protect shows you that the batteries and sensors are OK by glowing green for a moment. The light ring pulses yellow if the batteries are running down or a sensor isn’t working.

  7. Sound the alarm

    You’ll know there’s an emergency when you hear the horn sound in addition to a voice alarm. The horn will get your attention and the voice will tell you what’s going on.

    Talks to you

    In a potential emergency, you need to know what the danger is and where it is. This speaker will tell you exactly that in English.

  8. Long-life batteries

    You won’t need to switch out the batteries every year. And long before they run out, Nest Protect will notify you so you can replace the batteries and not suffer the dreaded low-battery chirp.

  9. Built to connect.

    Nest Protect uses Wi-Fi to talk to the Internet for alerts and updates to your Nest app. And even if Wi-Fi goes down, your Nest Protects stay connected to one another so you know what and where the problem is no matter what room you’re in.

    See system requirements

  10. Nest Protect

    All of these sensors and all of that thinking fit neatly inside Nest Protect. Together they create a smoke alarm that’s more friendly. That’s more thoughtful. And to us, this matters. Because the things that protect our families should be as brilliant as they can possibly be.

More than one colour.

To tell you more than one thing.

The Nest Protect light ring can display different colours depending on what’s going on. Watch the Video 

  • Nightly Promise

    Know you’re safe

    Nightly Promise

    Nest Protect constantly monitors its sensors and batteries. A quick green glow when you turn out the lights says everything’s working.

  • Pathlight

    A light in the dark


    Most of the time, the light is off. If you need a glass of water in the middle of the night, Nest Protect will quietly glow white to light your way.

  • Get a Heads-Up

    An early warning

    Get a Heads-Up

    If there’s only a little smoke, like you’ve just burned toast, it will glow yellow and give you a friendly Heads-Up so you can check on things.

  • Emergency Alarms

    In an emergency

    Emergency Alarms

    When smoke or carbon monoxide reaches dangerous levels, Nest Protect sounds the alarm, pulses red, and tells you where the emergency is.

Proven safe.

You have to know your smoke and CO alarm is safe. And we’ve proven ours is.

Safety testing is a rigorous process. We worked with leading agencies in three different countries. We passed an incredible number of tests. We answered their questions and all the agencies gave Nest Protect a thorough review. Learn more about Nest Protect testing >

BSI Kitemark
CE Mark

Everything’s connected.

Nest Protect is better with Wi-Fi. Once it’s on your network, you can tell each Nest Protect which room it’s in and get access to your smoke and CO alarm from your phone.

  1. It’ll send you a notification when an alarm goes off.

  2. See the battery and sensor status of any of your Nest Protects.

  3. See what to do in an emergency.

  4. Know what happened over the last 10 days with Safety History.

  5. Customize room names and turn on and off features like Pathlight and Heads-Up.

Tech Specs


6 AA Energizer Ultimate Lithium batteries

Long-life batteries designed for multi-year operation

Wired (230V)

3 AA Energizer Ultimate Lithium backup batteries

Long-life backup batteries designed for multi-year operation

External button and connector

  • Batteries

  • Nest button

  • Wired (230V)

  • Nest button

  • 230V AC connector

Size and weight

  • Height: 13.4 cm (5.28 inches)

  • Width: 13.4 cm (5.28 inches)

  • Depth: 4.1 cm (1.63 inch)

  • Weight: 372 grams (13.1 ounces)

  • Height: 13.4 cm (5.28 inches)

  • Width: 13.4 cm (5.28 inches)

  • Depth: 4.1 cm (1.63 inch)

  • Weight: 352 grams (12.4 ounces)


  • Photoelectric smoke sensor

  • Carbon monoxide sensor

  • Heat sensor

  • Three activity sensors

  • Ambient light sensor

  • Humidity sensor

Speaker and horn

  • Speaker Loudness: 80dB @ 1 meter @ 1kHz

  • Horn: 85 dB SPL @ 3 meters


  • Wi-Fi connection: 802.11 - 2.4 GHz

  • Wireless Interconnect: 802.15.4 - 2.4 GHz

System requirements

  • Wi-Fi connection

  • Smartphone or tablet with iOS 5 or later, or Android 2.2+ or later

  • Free Nest Account

  • Learn more >

Environmental information


  • Mercury-free

  • PVC–free

  • Recyclable packaging


  • This alarm should not be installed in locations where the normal ambient temperature is below 4°C (40°F) or exceeds 38°C (100°F).

  • Humidity Range: 20%RH to 80%RH (non condensing).


  • Languages available out-of-the-box: English (UK)


  • 2-year limited hardware warranty (see details inside)


Nest Protect has been tested to comply with safety standards in UK and Europe set out by BSI and European Regulations

Nest Protect complies with all of the following smoke and carbon monoxide alarm standards:

  • BS EN-14604 Smoke alarm devices.

  • EN-50291 - Electrical apparatus for the detection of carbon monoxide in domestic premises.

  • BS EN-50271:2010, Electrical apparatus for the detection and measurement of combustible gases, toxic gases or oxygen.

  • BS EN-50292 Electrical apparatus for the detection of carbon monoxide in domestic premises.

In the box

  • Nest Protect (Battery)

  • Six long-life batteries

  • Backplate

  • Four screws

  • User’s Guide and Welcome Guide

  • 2-year limited hardware warranty

  • Nest Protect (Wired 230V)

  • Three long-life backup batteries

  • Backplate

  • Four screws

  • User’s Guide and Welcome Guide

  • 2-year limited hardware warranty

  • AC 230V cable connector

  • Three terminal blocks

Replacement batteries (Energizer® Ultimate Lithium “L91” AA) available for purchase at your local retailer

Bring yours home

Buy Nest Protect today.

Visit our store >