To learn more about these devices, we spoke with an electrician experienced in installing smoke detectors and other smart home products. “We tell customers it’s great to have smoke detectors hardwired; that’s the best,” says Justin Landeen, vice president of business development and smart home installation manager for Penco Electric. With installation in mind, we researched and tested available options based on other essential features, including sensors, app control, and smart assistant compatibility. We consider the Google Nest Protect smoke and carbon monoxide (CO) alarm the top choice for most buyers because of its reliability, self-checking functions, and smart features. Here are our picks for the best smart smoke detectors. The Nest Protect even features advanced technology in terms of smoke detection, combining the strengths of photoelectric and ionization sensors into a split-spectrum sensor that better detects both smoldering and flaming fires, in addition to greatly reducing false alarms. Our tester reported that this alarm “is smart enough to distinguish real smoke from shower steam or minor cooking smoke.” When compared with two other models he tested, the Nest Protect was the only device that didn’t sound as a result of cooking—despite being “mounted right next to one of the offending alarms.” The built-in carbon monoxide (CO) detector is similarly accurate and lasts 10 years. The device also self-checks all its sensors and battery levels 400 times a day, with speaker tests once a month. Besides notifications on the app, the Nest Protect itself issues voice prompts that describe what’s happening (and where), with the ring of light around the center button changing colors. The ring’s glow can be activated via a motion sensor in the dark, serving as a night light that became a surprisingly valuable bonus feature in our reviewer’s home. With no option for wiring the XS03-WX directly to your electrical system, installing the device with the included mounting screws or adhesive is straightforward and quick. It fits well into just about any home setup, thanks to a compact circular shape at roughly 3 inches across and 2 inches deep. The smoke sensor is photoelectric, responding faster to smoldering fires than flaming ones, and there’s no carbon monoxide sensor (in this or any other X-Sense Wi-Fi models). For this reason, having separate ionization detectors and CO detectors is recommended for full coverage. On the safety side, the Safe & Sound holds up to the established reliability of the First Alert brand, with a photoelectric sensor and a carbon monoxide detector. It’s a hardwired alarm designed to easily replace your existing hardwired detector with a sealed-in 10-year lithium battery backup. It also includes a night light with customizable brightness and colors to help guide you in the dark. The Onelink smart alarm offers two-in-one smoke and carbon monoxide detection and the option to choose your power source: a hardwired model with a sealed 10-year battery backup or a version with a replaceable five-year battery and an easy-to-access battery door. The hardwired units can interconnect with compatible alarms, and the battery-operated ones can do so wirelessly. You also get remote app notifications common to smart smoke detectors, but Onelink notifications can be delayed and won’t trigger if an interconnected alarm sounds as opposed to the main unit. Importantly, the Ring Alarm Smoke and CO Listener requires the presence of a Ring Alarm Security System, so it makes sense primarily if you already have that smart security platform protecting your home. If you do, the listener adds a straightforward, easy-to-install fire prevention element to the mix. It’s worth noting that if you’ve signed up for professional monitoring through Ring, the listener will automatically dispatch the fire department to your home if it hears an alarm, with no way to cancel the call. This automation makes false alarms potentially costly affairs. Besides using a different wireless protocol, the Z-wave alarm works similarly to other smart smoke detectors. It sends mobile alerts through the smart home app you connect to, though it lacks extra features like voice prompts or self-checks. A photoelectric smoke sensor and an electrochemical CO sensor give it more versatility and convenience, as does an easily accessible battery compartment for basic AA batteries. However, there’s no option for hardwiring it to your electrical system or wirelessly interconnecting it with alarms outside of your smart hub. Installing the system involves connecting the base station to Wi-Fi and syncing the wireless smoke detectors to the base station. If any of them detects smoke, all alarms are triggered, and instant notifications go to the mobile app, where you can silence the alert if it’s a false alarm. While you won’t get carbon monoxide monitoring, each unit performs automatic checks of its sensors and replaceable batteries every 60 seconds, with any issues pushed to the app. If you want to expand your system, you can purchase individual add-on XS03-iWX alarms to a maximum of 32 units. Landeen recommends hardwiring but admits, “it’s not always the most cost-effective to hardwire an entire system.” Instead of a hardwired setup, he recommends “at least have battery-operated alarms in place and be very mindful of when the battery should be replaced.”

Sensors

Smoke detectors primarily use one of two types of sensor technologies: photoelectric and ionization. Photoelectric sensors tend to be more responsive to fires that have been smoldering for some time, while ionization sensors are quicker to pick up on flaming fires. Since dangerous house fires can be of either type, the recommendation is to have alarms with both types of sensors in your home. Some smoke alarms use a combination of both sensor technologies. Currently, the only smart detector with the combined capability is the Google Nest Protect with its Split-Spectrum Sensor.

Advanced Features

One important distinguishing feature between smoke detectors is detecting dangerous levels of carbon monoxide (CO). Two-in-one detectors often cost more but save you the need for separate CO monitoring devices in critical areas, such as near the kitchen, garage, furnace, and bedrooms. Another safety function of some smart smoke detectors is recurring automated checks of their sensors and battery to catch any issues between manual testing by the user. Other features like voice prompts or light indicators are offered mostly for convenience but can sometimes be surprisingly valuable in day-to-day use. “I would go with a smoke detector like the Google Nest Protect that enunciates the location of the alarm, which is always important when it comes to exiting the building in a safe manner,” says Landeen. “They also act as a motion-sensing night light in the ceiling, helpful especially if you have a dark walk to the bathroom.”

Why Trust The Spruce?

This article’s author, Anton Galang, is a freelance writer and editor who has worked with consumer technology for over 15 years. Since 2019, he has covered and reviewed a wide range of hardware, gadgets, and smart home products for Lifewire and The Spruce. Accessing your smoke detector from your phone can also have practical benefits outside of emergencies. Many products allow you to shut off or silence the alarm if you know it’s a false alarm. You can also test the batteries or other aspects of the device and see if there are any problems, all without needing to touch the smoke detector. “Generally speaking, these are outlets—power sources that you are installing at different locations,” says Landeen. “If you have the option, or you’re in the process of building or renovating your home, without a doubt, it’s worth the extra money for a hardwired system.” As for placing smart smoke detectors, you can set some up as part of an interconnected system of smoke and/or CO alarms across your home. This setup lets you apply internet-enabled benefits to all of your alarms through just one smart smoke detector. “The interconnected portion is important,” says Landeen. “Who’s to say there’s not a fire in the basement, and you’re in a second-floor bedroom? The interconnected smoke detector will alert the entire home that there’s a fire.” With the smart smoke detector market still relatively small, Anton researched the features, specifications, and reviews for most of the top options available, along with alternatives that performed similar fire safety functions. Anton also spoke with Justin Landeen, vice president of business development and smart home installation manager for Penco Electric, who contributed insights and recommendations from his experience with smart smoke detector installation in the Chicago area.