Nest Protect: 2nd Gen Smoke + CO Alarm

Free delivery

You’ll know, from anywhere

Nest Protect alerts your phone¹ when something’s wrong at home. Just burned the toast? When there’s only a little smoke, you can hush it with the Nest app on your phone or tablet.

It’s thoughtful, not annoying

Nest Protect tests itself over 400 times a day – just check the status in the Nest app. It also has a friendly human voice that gives you early warnings.

It tells you what and where the danger is

The new Split-Spectrum Sensor looks for both fast and slow-burning fires. It also has a 10-year CO sensor, so it can tell you where poisonous, invisible CO is hiding.

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.

Works with your Nest Thermostat and Nest Cam

If Nest Protect sounds the alarm, it tells your Nest Thermostat to turn off the boiler – the most common source of carbon monoxide leaks. Your Nest Cam will also record a clip so that you can see what happened.

Tech specs
Dimensions & weight
5.3 in L • 5.3 in H
Split-Spectrum Sensor
Six long-life AA batteries
802.11 b/g/n @ 2.4GHz
Operating temperature
40ºF (4ºC) to 100ºF (38ºC)
80 dB @ 3 ft (1 m) @ 1kHz
85 dB SPL @ 3 m (10 ft)
Two-year limited warranty
Complies with safety standards set out by UL
External Buttons
RGB colour ring with 6 LEDs

What's in the box

Nest Protect: 2nd Gen Smoke + CO Alarm
Four screws
User guide
Welcome Guide
Six long-life AA batteries (Battery model)
Three long-life backup AA batteries (Wired model)
120 V AC connector (Wired model)
Three wire nuts (Wired model)


Wi-Fi connection.
Phone or tablet with iOS 8 or later, or Android 4 or later
Free Nest account.

¹The Nest App is compatible with iOS devices running iOS 8 or later and Android devices running Android 4 or later. A 2.4 GHz Wi-Fi network and Internet connection are required in order to monitor Nest Protect and receive alerts in the Nest app on your smartphone.

† To qualify for free delivery at the lowest cost, your order total must be at least $45 before estimated taxes and after any discounts are applied. Separate, multiple orders cannot be combined to total $45 or more to receive free delivery. Learn more