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


  • White


  • Voice alarms with custom location
  • Split‑Spectrum Sensor
  • Detects carbon monoxide
  • Up to 10-year product lifetime
  • Heads-Up alerts
  • Sound Check
  • Nightly Promise
  • Pathlight
  • Steam Check
  • Self Test
  • Wireless Interconnect
  • Emergency Shut-Off with Nest Learning Thermostat
  • Emergency clip record with Nest Cam
  • Home Report
    • Nest App
    • Smoke
    • Carbon monoxide
    • Low battery
    • Sensor failure
  • App Silence
  • Safety Check-up
  • 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 (120° field of view up to 6 m [20 ft])
  • Ambient light
  • Accelerometer
  • Microphone

Speaker, siren
and light ring

  • 2-watt speaker
  • Siren: 85 dB at 3 metres
  • RGB colour ring with 6 LEDs

Size and weight

  • Height: 13.5 cm
  • Width: 13.5 cm
  • Depth: 3.85 cm
  • Mass: 379 g
  • Height: 13.5 cm
  • Width: 13.5 cm
  • Depth: 3.9 cm
  • Mass: 374 g


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


  • 802.11b/g/n (2.4 GHz) Wi-Fi
  • 802.15.4 (2.4 GHz)
  • Bluetooth low energy


  • The 2nd generation Nest Protect has been tested by UL to comply with European, US and Canadian safety standards. Nest Protect complies with all of the following smoke and carbon monoxide alarm standards:
  • EN-14604 – Smoke alarm devices.
  • EN-50291 – Electrical apparatus for the detection of carbon monoxide in domestic premises.
  • EN-50271:2010 – Electrical apparatus for the detection and measurement of combustible gases, toxic gases or oxygen.
  • EN-50292 – Electrical apparatus for the detection of carbon monoxide in domestic premises.


  • The 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).



  • 2-year limited warranty. For support, visit nest.com/dk/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)
  • Back plate
  • Four screws
  • User’s Guide and Welcome Guide

Nest Protect (wired)

  • Nest Protect (Wired 230 V)
  • Three long-life back-up batteries
    (Energizer® Ultimate Lithium “L91” AA)
  • 230 V connector
  • Three terminal blocks
  • Back plate
  • 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 >

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.

It uses a 450 nm wavelength of light to detect the tiny particles created by fast fires. It also uses a second, 880 nm infrared wavelength to look for the larger particles created by smouldering fires. It’s the first sensor in a home alarm to use two sources of light to get a more accurate picture of a 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 insects and fibres 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 siren 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 is running and deletes the audio afterwards. 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 sensors 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 uses both a humidity sensor and an advanced algorithm to cut false alarms from steam by 50%

Learn more about Steam Check >

Designed to connect.

Nest Protect uses Wi-Fi to securely send alerts to your phone. It also has Bluetooth LE so you can set up your alarms quickly and silence a false alarm with your phone. All your Nest Protects also talk to each other using reliable Weave technology. Even if the Wi-Fi goes down, your Nest Protects can still tell you what and where the trouble is.

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 colours to communicate. And we’ve given 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 off 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 when you’ve burnt the 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 aren’t always at 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’s happened and tips to help you stay safe.

    See an example >