Finding The Strongest Smart Smoke Detector Options For 2021

While many smart-home devices are primarily designed to make your life more convenient, a smart smoke alarm is one investment that could end up saving your life or the lives of those you love. Through operational enhancements and added safety features, smart smoke alarms eliminate many of the deficiencies of traditional alarms.

With standard smoke alarms, the unit could malfunction without a home’s occupants ever being aware that anything is wrong. In fact, according to a 2014 report by the National Fire Protection Association, 25 percent of all residential fire fatalities between 2007 and 2011 occurred in homes that had smoke detectors that weren’t working properly at the time of the fire. Smart smoke alarms can help prevent these tragedies in part by making it easier to silence false alarms through a mobile app, so users aren’t tempted to remove the battery to stop the intrusive sound.

How Do Smart Smoke Detectors Work?

Both traditional and smart smoke alarms rely on one of two types of sensors: ionization and photoelectric.

  • Ionization sensors work by using a small amount of radioactive substance that converts air molecules into positive and negative ions. When smoke enters the unit, the ions bond with the smoke molecules, interrupting the path of electricity inside the unit’s circuit and triggering the alarm. Ionization technology is most effective in detecting fast-flaming fires that tend to start as cooking fires or fires igniting in a wastebasket.
  • Photoelectric smoke alarms contain an LED light that sends a beam across the interior chamber of the unit. When smoke enters the chamber, it scatters the beam of light, activates the sensor and sets off the alarm. Photoelectric sensors are most effective in detecting smoldering fires, which can burn slowly for hours before igniting a flame and are often caused by unattended candles and cigarettes.

However, unlike traditional smoke detectors, smart smoke detectors are equipped with self-testing features to monitor battery power and proper sensor function are programmed to send you a smartphone notification when anything is amiss.

What to Look for in a Smart Smoke Alarm

First and foremost, any smart smoke alarm worth your money will include carbon monoxide detection as well as smoke and fire detection. It should deliver smartphone notifications when it detects smoke as well as when the battery is low or the unit isn’t functioning properly. It should also identify where the alert is occurring and include voice alert and silencing features. If you use other smart-home devices, you’ll also want to look for a unit that’s compatible with your existing systems.

Another valuable feature of most smart smoke alarms is interconnectivity, causing all alarms to sound when one unit detects smoke. No matter how large your home is, having interconnected alarms can make the difference in safely evacuating your home in time to escape injury or worse.

Best Overall: Nest Protect ($159)

The well-rounded Nest Protect smoke and carbon monoxide alarm offers the best combination of features in any smart smoke alarm on the market: it’s easy to install and operate; it uses a comprehensive mix of voice, siren and mobile alerts; it monitors battery life and function and delivers unobtrusive notifications if either of these areas needs to be addressed; and it allows users to stop false alarms from within the app (instead of having to stumble out of bed at 2 a.m. and climb a ladder to silence a malfunctioning unit). Additionally, the unit maintains the Nest product line’s sleek, modern aesthetic, making it a more attractive addition to your home than most traditional alarms.

The unit relies on Nest’s “split-spectrum sensor,” which is essentially a photoelectric sensor with a second LED designed to better detect fast-burning fires while reducing the incidence of false alarms. On the rare occasion there is a false alarm, you can silence it almost instantly through the Nest smartphone app (unless the system really does detect smoke, in which case you wouldn’t want to disable it).

The Nest Protect also provides a gentle “Heads Up” voice warning when low levels of smoke are present—say from a burning toaster—so you can eliminate the source of the smoke before the detector launches into a more disruptive siren alert.

In addition to standard smoke and carbon monoxide detection, the feature-rich Protect contains sensors for humidity, room occupancy and light. These sensors help the Protect work with other smart-home devices like the Nest Learning Thermostat and Nest Cam to turn off the HVAC system or begin recording video when the alarm is activated. The Protect also works with other non-Nest smart devices, including the SkyBell HD video doorbell, the Rachio 3 smart sprinkler controller and Lutron smart shades, all of which can be programmed to take action if the Protect detects smoke or dangerous levels of carbon monoxide.

The Nest Protect conducts frequent self-tests to ensure that the unit is functioning correctly, including sensor tests every 3.5 minutes and monthly self-checks of its speaker and horn. You’ll receive notifications from the app if anything isn’t working properly, and you’ll also see a yellow light on the unit indicating that something is wrong.


  • Easy installation – mounting screws are included, and no interconnect wire is required
  • Frequent self-tests let you know when unit isn’t functioning properly
  • Compatible with multiple smart-home systems
  • Smartphone app delivers relevant notifications and other critical status information
  • Split-spectrum sensors minimize false alarms


  • Expensive, especially when installing multiple units throughout your home
  • Relatively short two-year warranty

Best Budget Model: Kidde RF-SM-DC ($32)

Though it lacks the bells and whistles of some of its competitors, the Kidde RF-SM-DC delivers excellent interconnectivity at a price that won’t break the bank. The unit relies on radio frequency to communicate with other alarms and smart-home devices in your home so when one device is triggered, they all respond. The wireless system is powered by three AA batteries, which helps keep the model’s cost low but also means you’ll still experience the annoying low-battery chirp familiar to homeowners with traditional alarms.

The one-touch Smart Hush feature allows users to quickly silence nuisance alarms resulting from non-emergency situations like cooking smoke. If the unit still senses smoke after an eight-minute hush period, the alarm will sound once again. Like an alarm clock’s snooze button, the Smart Hush feature can be employed repeatedly until the air has cleared.


  • Affordable price
  • Convenient Smart Hush feature
  • Good interconnectivity
  • Extensive 10-year warranty


  • No companion smartphone app
  • Unit relies solely on ionization sensors, which may not be as effective in some types of fires

Best Value: First Alert 2-in-1 Z-Wave Smoke Detector ($45)

The affordable First Alert 2-in-1 Z Wave Smoke Detector—which also detects carbon monoxide—is an excellent choice for households on a tight budget that require multiple alarms. Equipped with both electrochemical and photoelectric sensors for maximum effectiveness and reduced false alarms, the battery-operated unit connects wirelessly to a Z-Wave Hub to send you mobile alerts and emails when the alarm is activated. It also works with Nexia Home Intelligence, SmartThings, Ring security cameras and other Z-Wave-compatible systems.


  • Affordable price
  • Z-Wave compatibility


  • Alarm can’t be silenced remotely
  • Limited mobile notifications and functionality

Best Splurge: First Alert Onelink Safe & Sound ($217)

The hardwired First Alert Onelink Safe & Sound comes with an integrated Alexa-enabled omnidirectional Bluetooth speaker and is the only smart smoke alarm that’s compatible with Apple’s HomeKit system. The unit includes photoelectric smoke sensors and electrochemical carbon monoxide sensors to accurately detect fires, gas leaks and other dangers.

The First Alert Onelink Home mobile app allows you to manage your alarm remotely, track carbon monoxide levels, customize night light settings, receive notifications and more. Meanwhile, the alarm can connect to any other hardwired alarm in your home—even those made by other brands—and will send an alert through the Onelink Home app to notify you of any emergency.

This premium model also includes a fully functional Alexa speaker, which can be used to play music, stream podcasts, check weather and news and control other smart-home devices.


  • On-board Alexa speaker adds broad functionality
  • Voice location technology communicates the type and location of danger in your home
  • HomeKit-compatible
  • Alarms may be silenced through the app or on the device


  • High price tag makes it cost-prohibitive to buy multiple units
  • Doesn’t provide early warnings for alarms

Best Smart Accessory: Roost Smart Battery ($35)

While not an actual smoke alarm, the Roost Smart Battery is an economical way to receive remote notifications when your alarm is triggered. The 9-volt battery is equipped with a built-in microphone and Wi-Fi chip, transforming any traditional smoke alarm that accepts a 9-volt battery into a smart unit.

The Roost battery works with the companion mobile app, which you’ll use to set up the battery as a temporary Wi-Fi hotspot. Once you’ve completed the simple, step-by-step process, you’ll install the battery in your current smoke detector and push its test button, which will then trigger an alert on your phone. The battery does require a connection to your home wireless network to send you notifications through the app, so if your power goes out or your Wi-Fi goes down, you won’t get mobile alerts, although the battery will continue to power the smoke alarm.

Beyond these in-app notifications, the Roost battery lacks any other smart-home functionality and doesn’t integrate with other smart-home systems, but it’s an economical choice if you want to be able to manage your alarm from your phone and don’t want to invest in all-new smoke detectors to replace your existing functional alarms. It should be noted, however, that the battery also doesn’t create interconnectivity with other alarms in your home, even if they all have Roost batteries installed.


  • Low-cost alternative to purchasing all-new smoke alarms
  • Mobile alerts delivered through Roost app
  • Five-year battery life
  • Easy to install


  • Very limited smart-home functionality
  • Doesn’t create wireless connections among all smoke alarms in your home
  • No integration with smart-home systems

Final Thoughts

Whether you opt for traditional smoke alarms or decide to make the investment in smart alarm systems, fire-safety experts recommend replacing them every 10 years to ensure that the sensors are still working properly. Making the switch to smart smoke alarms can significantly raise the cost of this decennial replacement, but the peace of mind you’ll get from knowing your family is fully protected from fire and carbon monoxide dangers is well worth the money spent.

Smart smoke alarms offer you the ability to confirm that all units are operating in their full capacity, and buying interconnected models can provide you with critical extra minutes to escape your home in case of an emergency. Smart alarms also offer the convenience of managing the unit through a mobile app, so you’ll never again have to get out of bed in the middle of the night to silence a chirping unit. For all of these reasons, we think it’s well worth the extra money to upgrade to smart smoke alarms in your home.

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