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Best smart smoke detectors in 2021

Best smart smoke detectors

The best smart smoke detectors add a layer of extra protection to your house or apartment by alerting you to a dangerous condition — whether you're home or not. That's because smart smoke detectors will not only sound an alarm, but send a signal to the cloud, so you can be alerted on your smartphone. 

Additionally, some smart smoke detectors can be connected to other smart home devices. For example, if there's a fire, the smart smoke detector can tell your smart lights to turn on, helping show you the way out of your house in smoky conditions. 

What is the best smart smoke detector?

There's not a lot of choice when it comes to smart smoke detectors. Our favorite for a few years running is the Nest Protect. It's the most full-featured alarm, blaring out a loud siren and telling you where the problem is. If you have one mounted near your kitchen, it will also send out a warning that it's about to go off, so you can silence it if all you're doing is cooking up some steaks. We also like that it performs a self-check every month, and can be linked with other Nest Protects. It has a 10-year battery, too.

It works with a lot of other smart home systems, so for example it can turn on all your Philips Hue lights, making it easier to find your way out—but only if you haven't converted your Nest account to a Google Assistant account.

If you don't want to spend more than $100 on a smart smoke detector, or already have a number of functioning smoke detectors in your home, then check out the Roost Smart Battery. This 9-volt Wi-Fi connected battery goes into any smoke detector, and alerts your phone when the alarm goes off. However, you can't connect it directly to any other smart home devices.

If you already have a number of non-smart smoke detectors, an inexpensive option is to use Alexa Guard. When enabled, your Alexa smart speakers will listen for smoke and CO2 alarms, and will send you an alert on your smartphone if they hear a siren. It can also be connected to some of the best DIY home security systems, such as those from ADT and Ring.

Make sure you check out all of our top picks for smart speakers, lights, locks, and more on our best smart home devices page.

The best smart smoke detectors you can buy today

Best smart smoke detectors: Nest Protect

Nest Protect (Image credit: Nest)

1. Nest Protect

The best smart smoke detector overall

Detects: Smoke, carbon monoxide
Works with: Nest, Google Home, Philips Hue, IFTTT, Wink, Lutron
Hardwired/battery: Yes/Yes
Reasons to buy
+Detects both smoke and carbon monoxide+Can be linked with other Nest Protects+Comes in both wires and battery-powered versions
Reasons to avoid
-Does not work with Alexa-Most smart-home functionality lost when switching to Google account.

Nest’s smoke alarm detects both smoke and carbon monoxide, and when it does pick up something, it will not only sound an alarm, but will also tell you in what room the alert is coming from, and the nature of the alert. An LED ring on the bottom of the alarm also changes color, giving you a visual cue.

The Nest Protect comes in both wired and battery-powered versions. If you have more than one in your home, and one goes off, the others will too, alerting you to the location of the fire.

The Nest Protect also works with a wide range of smart-home devices. For example, in the event of an emergency, the Nest can automatically turn on your lights, making it easier for you to get out of your house. However, this only works for those who have not converted their Nest account to a Google Assistant account. It also does not natively work with Alexa.

Read our full Nest Protect review.

Best smart smoke detectors: Roost Smart Battery

Roost Smart Battery (Image credit: Roost )

2. Roost Smart Battery

This battery makes any smoke detector "smart"

Detects: n/a
Works with: n/a
Hardwired/battery: No/Yes
Reasons to buy
+Works with any smoke detector with a 9-volt battery+Inexpensive
Reasons to avoid
-No smart home compatibility

The Roost battery is the best — well, only — option for those who already have smoke detectors, and want to make them “smart.” That’s because the Roost battery, which is Wi-Fi- enabled, sends an alert to your smartphone when the siren goes off. The second-generation battery looks and acts like the original, but has a much easier setup process.

Through the app, which can accommodate a large number of connected batteries, you have the option to silence the alarm for up to 2 minutes, and automatically send an alert to someone else. However, it no longer works with IFTTT—nor any other smart home system—to, say, turn on your lights when the alarm goes off.

The battery is designed to last up to five years, and will work with any smoke/CO alarms that use a 9-volt battery, which includes hard-wired alarms with a 9V battery backup.

Roost has updated its app so that users can get notified when there is a severe weather alert, such as hail, freezing temperatures, heavy rainfall and snow, and storms and high winds. 

Read our full Roost smart battery review.

Echo Dot with Clock review

(Image credit: Tom's Guide)

3. Amazon Echo Dot

Alexa Guard sends you alerts

Detects: n/a
Works with: Alexa
Hardwired/battery: No/Yes
Reasons to buy
+Inexpensive+Fuller sound than original+Fair price for a smart alarm clock
Reasons to avoid
-Large power brick

The Amazon Echo Dot doesn't have a smoke detector built in, but if you enable Alexa Guard, it can listen for smoke and CO2 detectors (as well as glass breaking), and alert you on your smartphone if if hears something. This way, you can keep your older smoke detectors, but still get a notification on your phone if you're away and something's amiss.

The Echo Dot comes in three versions: The 4th-generation Echo Dot ($49), the 4th-generation Echo Dot with Clock ($59, and our favorite), and the 3rd-generation Echo Dot ($29). 

Read our full Amazon Echo Dot review.

Best smart smoke detectors: OneLink Safe & Sound

OneLink Safe & Sound (Image credit: First Alert)

A smoke detector with Alexa inside

Detects: Smoke, carbon monoxide
Works with: Alexa, Homekit
Hardwired/battery: Yes/No
Reasons to buy
+Alexa built in+Pretty good speaker+Works with HomeKit
Reasons to avoid
-Only works with hardwired smoke detectors

Like the Nest Protect, the OneLink Safe & Sound detects smoke and carbon monoxide, sends an alert to your smartphone, and tells you the type and location of the fire or condition. But for those times when it's not warning you of fire, you can use it for a great many other things. With Amazon's Alexa (and a very competent 10-watt speaker), the Safe & Sound can play music, listen to audiobooks, and access Alexa's thousands of skills. (It's also compatible with Apple's HomeKit, as well as AirPlay). 

However, the Safe & Sound requires a hard-wired connection, and we found that the location of these connections doesn't make it the most conducive for using all of Alexa's capabilities. 

Read our full OneLink Safe & Sound review.

Best smart smoke detectors: Onelink Smart Smoke + Carbon Monoxide (2nd Gen)

Onelink Smart Smoke + Carbon Monoxide (2nd Gen) (Image credit: Onelink)

Works with Alexa and HomeKit

Detects: Smoke, carbon monoxide
Works with: Alexa, HomeKit
Hardwired/battery: Yes/Yes
Reasons to buy
+Works with Alexa and HomeKit+Comes in wired and battery powered versions+Interconnectable
Reasons to avoid
-No Google Assistant compatibility

The second-generation Onelink Smart Smoke + Carbon Monoxide alarm comes in battery and hardwired models. Similar to the Nest Protect, the Onelink will not only sound an alarm, but also specify the room affected and the type of alert: smoke or carbon monoxide. Also like the Nest Protect, if you have more than one Onelink alarm, you can interconnect them so that if one goes off, they all will. 

An LED rings the middle of the alarm and changes color based on the alarm's status. Green and blue indicate that the alarm is starting up or in pairing mode. Yellow means there's a malfunction or a low battery, while red means there's a fire or smoke condition.

Onelink's alarm uses photoelectric technology, which is generally better at detecting smoldering fires than are alarms that use ionization technology. However, the latter are better at detecting fast-burning fires.

The Onelink can be connected to HomeKit and Alexa (but not Google Assistant), so you can ask both Siri and Amazon's voice assistant for the status of the smoke detector, but not much else. By contrast, if the Nest Protect detects fire or carbon monoxide, you can have it automatically turn on a security camera, open Lutron blinds, turn on Philips Hue lights, turn off your heat and more. 

Setup should theoretically be easy—just scan a HomeKit code in the Onelink app—but it took a few tries to get it to work. The Onelink smoke and carbon monoxide alarm is good on its own, but the Nest Protect does more for the same price. 

How to choose the best smart smoke detector

Fire and smoke detection sensors

All smoke detectors use one of two types of sensors to detect fires. Ionization-type sensors are best at detecting fast-burning fires, while photoelectric sensors are generally better at alerting you about smoldering, or slow-burning fires. You should have both types of alarms in your house. Smoke alarms such as the Nest Protect are designed to pick up both types of fires.

Carbon monoxide and other gas detection

Even if you don't have a fire in your home, you can be suffocated by carbon monoxide. A good detector should also protect you against this.

Hardwired vs. battery-powered

If your home has hardwired alarms, they will all be interconnected, so that if one goes off, they all will go off. Hardwired alarms also receive their power from your home, and only use batteries as backups. Standalone detectors run on batteries alone, so they may need to be replaced more often, and cannot signal each other in the event of an emergency (Nest's and OneLink's alarms are an exception to this). However, it's a lot easier to mount standalone smoke detectors where you need them.

Mike Prospero

Michael A. Prospero is the deputy editor at Tom’s Guide overseeing the smart home, drones, and fitness/wearables categories. When he’s not testing out the latest running watch, skiing or training for a marathon, he’s probably using the latest sous vide machine or some other cooking gadget.