Overview Specs
Buy now

This is going to be easy.

You can set up your Nest Protect in just minutes using your iPhone, iPad, or Android device.

And Nest Protect is now even easier to install. But if you need help, we have customer support with real humans to answer your questions.

Watch the installation video

Low on time? Scared of wires?

Find a Nest Pro in your area >

Tech Specs


  • 2nd Generation


  • Six long-life AA
  • Energizer® Ultimate
  • Lithium batteries
  • 120V Connector
  • Three long-life AA
  • Energizer® Ultimate
  • Lithium backup batteries


  • White


  • Voice alarms with custom location
  • Split‑Spectrum Sensor
  • Detects carbon monoxide
  • 10-year product lifetime
  • Heads-Up alerts
  • Sound Check
  • Nightly Promise
  • Pathlight
  • Steam Check
  • Self Test
  • Wireless Interconnect
  • Emergency Shutoff with Nest Learning Thermostat
  • Emergency clip record with Nest Cam
  • Home Report
    • Nest app
    • Smoke
    • Carbon monoxide
    • Low-battery
    • Sensor failure
  • App Silence
  • Safety Checkup
  • Safety History
  • What To Do


  • English (US, UK)
  • Danish
  • Dutch
  • Finnish
  • French (Canada, France)
  • German
  • Italian
  • Norwegian
  • Spanish
  • Swedish


  • Split‑Spectrum smoke sensor
  • 10 year electrochemical carbon monoxide sensor
  • Temperature
  • Humidity
  • Occupancy
  • Ambient light
  • Accelerometer
  • Microphone

Speaker, horn,
and light ring

  • 2 Watt Speaker
  • Horn: 85dB SPL at 10 feet (3 m)
  • RGB color ring with 6 LEDs

Size and weight

  • Height: 5.3 inches (13.4 cm)
  • Width: 5.3 inches (13.4 cm)
  • Depth: 1.5 inch (3.85 cm)
  • Mass: 13.9 ounces (379 g)
  • Height: 5.3 inches (13.4 cm)
  • Width: 5.3 inches (13.4 cm)
  • Depth: 1.5 inch (3.85 cm)
  • Mass: 13.2 ounces (375 g)


  • Wi-Fi connection with internet access
  • Nest app on phone or tablet with Android or iOS. See the Nest app requirements for supported versions.
  • Free Nest Account


  • 802.11b/g/n (2.4GHz) Wi-Fi
  • 802.15.4 (2.4GHz)
  • Bluetooth Low Energy


  • Nest Protect has been tested to comply with safety standards in the United States set out by:
  • UL
  • California State Fire Marshal

  • Nest Protect complies with all of the following smoke and carbon monoxide alarm standards:
  • UL 2034 - “Single and Multi Station Carbon Monoxide Alarms”
  • UL 217 - “Single and Multi Station Smoke Alarms”
  • NFPA-72 - “National Fire Alarm and Signaling Code”


  • The alarm should not be installed in locations where the normal ambient temperature is below 40°F (4°C) or exceeds 100°F (38°C).
  • Humidity range: 20%RH to 80%RH (non condensing).



  • 2-year limited warranty. For support, visit nest.com/support
  • Our support team is also available by phone.

In the box

Nest Protect (Battery)

  • Nest Protect (Battery)
  • Six long-life batteries
    (Energizer® Ultimate Lithium “L91” AA)
  • Backplate
  • Four screws
  • User’s Guide and Welcome Guide

Nest Protect (Wired)

  • Nest Protect (Wired 120V)
  • Three long-life backup batteries
    (Energizer® Ultimate Lithium “L91” AA)
  • AC 120V connector
  • Three wire nuts
  • Backplate
  • Four screws
  • User’s Guide and Welcome Guide

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

Learn more about the Nest Protect batteries >

Which Nest Protect should I get?

Just check the smoke alarm you have now. If it connects to wires, you’ll want Nest Protect (Wired 120V). If it doesn’t, you should get Nest Protect (Battery).

  • Battery

  • Wired 120V

As furniture and construction materials have changed, so has fire. Fires now burn much faster. The smoke is more toxic. Nest Protect has the technology to detect today’s fires.

As furniture and construction materials have changed, so has fire.

Fires now burn much faster. The smoke is more toxic.

Nest Protect has the technology to detect today’s fires.

Beautiful on the outside.

Rocket science on the inside.

Dive in >

The Split‑Spectrum Sensor looks for fast and slow burning fires.

Ionization alarms use radiation to detect fast-flaming fires. Photoelectric alarms are better at seeing smoldering fires. The Split‑Spectrum Sensor looks for both. Instead of radiation, it uses a 450nm wavelength of light to detect the tiny particles created by fast fires. It also uses a second, 880nm infrared wavelength to look for the larger particles created by smoldering fires. It's the first sensor in a home alarm to use two sources of light to get a more accurate picture of the fire.

Learn more about the Split‑Spectrum Sensor >

It's also designed to detect smoke, not cry wolf.

To reduce false alarms, the Split‑Spectrum Sensor is shielded against outside light, etched to protect it against dust, and encased in a stainless steel screen. The screen’s hexagonal pattern is designed to let smoke in and keep bugs and fibers out.

Ionization detectors are eight times more likely to false alarm. Source: Western Journal of Medicine

10-year carbon monoxide sensor.

Many alarms that detect carbon monoxide expire after 7 years. Now Nest Protect has a new electrochemical carbon monoxide sensor that lasts up to a decade.

What should I do if there’s carbon monoxide in the house? >

It has a microphone to test the alarm.

Nest Protect uses its microphone to quietly test the speaker and horn once a month. That way you know there will be an alarm and a voice alert if something goes wrong. To protect your privacy, the microphone only listens while the test runs and the audio is deleted. You can turn Sound Check on or off in the Nest app and schedule when it happens.

Listen to Sound Check Learn more about Sound Check >

Nest Protect can see movement and light.

The motion and light sensor work together to turn on Pathlight to light your way at night. The light sensor also triggers Nightly Promise, which lets you know if everything’s working when you turn out the lights.

The humidity sensor looks for steam.

Nest Protect is the first alarm to use both a humidity sensor and an advanced algorithm to cut false alarms from steam by 50%.

Learn more about Steam Check >

Designed to connect.

If the Nest Protect in your kitchen senses danger, every Nest Protect in your home will speak up to make sure you know where the danger is – even if Wi-Fi goes down. And once you've checked that everything's OK, you can hush them from your phone over Bluetooth LE.

Learn more about wireless interconnect >

When you go to bed tonight, look at your old smoke alarm.
You’ll probably notice a tiny little light. It could be green. Or red.
But what does it even mean?

Look for the light ring.

In addition to its voice, Nest Protect uses colors to communicate. And we gave the new Nest Protect a brighter light ring so it’s easier to see in an emergency and better at helping you see things in the dark.
What will I see and hear from Nest Protect? >

  • Nightly Promise

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

  • Pathlight

    When you walk under Nest Protect at night, it will light your way. You can choose different light levels or turn Pathlight off entirely in the app.
    How do I adjust the brightness? >

  • 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

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

Nest Protect helps you before, during, and after something goes wrong.

  • Not just an alarm. A guide.

    What To Do in the Nest app teaches your family how to get out of the house safely. It will also pop up on your phone if the alarm goes off. You can even enter an emergency contact so it's right there when you need it.

    Learn more >

  • Know what happened.

    You’re not always home when there’s an emergency. So Nest Protect remembers what happened and shows you the details in a 10-day Safety History.

    Learn more >

  • It helps you every month.

    Nest will email you a monthly Home Report. You’ll see a summary of anything that happened and tips to help you stay safe.

    See an example >

Proven safe.

You have to know your smoke and carbon monoxide alarms are safe. And we’ve proven Nest Protect is.

Meets all these standards:

How is Nest Protect certified? >