Smoke and carbon monoxide (CO) detectors–sometimes one in the same device, in other cases, discrete products–warn of imminent danger, so you can get out of your home as soon as possible. The smart versions of these life-safety devices go further, alerting you to danger from smoke, fire, or a malfunctioning appliance even when you’re not home. They’ll not only have the potential to save lives, they also protect your most substantial financial investment.
When paired with their relevant apps, you’ll not only get an audible alarm inside your home, you’ll also get a notification on your smartphone–wherever you happen to be. What’s more, many smart smoke detectors hook into your other smart home gear, so an alarm can trigger your smart lighting to flash or change color when danger is detected. And then there’s the convenience aspect: No more hunting down midnight chirps, since you’ll get specific notifications about dying batteries on your smartphone, too.
Update, July 10, 2024: We’ve posted a link to our Kidde Detect 10 Year Smoke + Carbon Monoxide Alarm review. Technically speaking, it’s a dumb thermostat since it doesn’t connect to Wi-Fi, but it has every other feature you could want from this type of home safety device, including a backup battery that should last for the life of the device, voice alerts for fire and carbon monoxide, and it can interconnect with other detectors, so that if one goes off, they all do. It’s on the expensive side, but there are cheaper versions if you’re willing to give up some of the features, such as the voice alerts. It’s a great value overall.
Our top picks in smart smoke detectors
Nest Protect — best smart smoke alarm overall
Pros
- Clear and versatile alerts
- Dead-simple, foolproof app
- Works with a variety of other products if you have other Nest gear
Cons
- Quite expensive, but not at the top of the market
The Nest Protect is one of the most mature smart smoke alarms on the market, and it’s a no-brainer of a choice if you want one of the most sophisticated and reliable smart smoke detectors out there. Alarms are varied, integrated lighting is color-coded based on the type of threat, and the product includes helpful voice alerts when activated. In testing, our phone was alerted almost immediately, and the app couldn’t be simpler to master.
Kidde Smart Detection Smoke + Carbon Monoxide Alarm — Best smart smoke detector overall, runner-up
Pros
- An affordable step above “dumb” detectors
- Emits voice warnings for fire and carbon monoxide danger, in addition to beeps
- Compatible with existing interconnected Kidde detectors
- Nuisance alarms can be silenced in the smartphone app
Cons
- Must be hardwired for power as well as interconnect to other alarms
- No wireless interconnect features
- Voice commands are for system status only
- Setup instructions could be better
Adding wireless features to your smoke and carbon monoxide detection system is one of the best smart home investments you can make, and Kidde’s solution won’t break the bank.
X-Sense XS01-WT Wi-Fi smoke alarm — Best budget-priced smart smoke detector
Pros
- Handsome, petite design
- Easy setup and intuitive operation
- Compellingly low price
Cons
- Does not detect carbon monoxide
- Units cannot be interconnected
- No support for voice assistants
The X-Sense XS01-WT isn’t nearly as smart as the Nest Protect or Kidde products. It won’t warn you of dangerous levels of carbon monoxide in your home, and you can’t interconnect multiple units so that when one sounds off, they’ll all sound off. But its $40 list price makes it a compelling home-safety value.
Kidde Detect 10 Year Smoke + Carbon Monoxide Alarm (model 30CUA10-V) — Best "dumb" smoke detector
Pros
- Fast to detect, faster to clear
- Easy installation, including interconnect features
- 10-year lifespan means no changing batteries
Cons
- No smart features
- Busy design
- High price for no smart features
As the headline above declares, this Kidde smoke and CO detector is not a smart device–it does not connect to your Wi-Fi network. But it does have every other feature you could want in such a home safety device, including voice alerts that warn you of fire and the presence of deadly carbon monoxide. This top-of-the-line model is AC powered with the ability to interconnect to other smoke detectors in your home, so that if one sounds off they all will. It’s expensive, but there are several other models in the same product line with fewer features–smoke but not CO detection, no voice alerts, AA battery power only, and so on–with lower price tags.
What do I need to know about smart smoke detectors?
For the most part, smart smoke alarms tend to work almost identically. The device installs on the ceiling or high on the wall (typically replacing an old-school smoke alarm in the same location), either using batteries or in-wall power. Most of the smart smoke alarms we evaluated are available in either format and cost the same. When shopping, pay close attention so you don’t end up with the wrong type.
If you’re upgrading a hardwired model, it’s important that you replace all the detectors in the chain with the same make and model. One of the reasons for hardwiring a smoke detector is that if one detects a dangerous condition, it can trigger all the others to go off. But there’s no guarantee that feature will work if you have a mix of devices from different manufacturers wired together.
What should I look for when shopping for a smart smoke detector
Smoke and CO: Your home needs to warn against the danger of carbon monoxide as well as smoke. Some detectors will do both, so you don’t need to deploy–and monitor the batteries in–more than one device.
Detector sensitivity and accuracy: It’s very difficult to scientifically test how well a smoke/CO detector does its primary job without actually burning your house down. That said, simulating smoky conditions can reveal a little about how sensitive a detector is. As well, you can consider the general consensus about the underlying technology in a smoke detector. The Nest Protect, for example, uses a photoelectric split-spectrum sensor that is considered superior to the ionization sensor used in many older devices and which is more prone to false alarms.
Notification variety: A loud siren is expected, but voice alerts are quite handy: They not only tell you what type of hazard has been detected, but also alert you to its location and can even tell you how to respond (whether that’s opening a window or calling 911). Color-coded lights on the alarm itself are another plus. And, of course, speedy push notifications to your phone are a must in the smart alarm space.
Multiple users: Obviously you’re safest if more than one person receives a push alert that there’s a fire in the house. Look for a system that supports multiple users through an invitation system.
Interconnectivity: Some devices support an interconnectivity feature, so if one alarm goes off, all the other alarms in the house will go off as well. This can be a big benefit if you have a very large home and fear you might not hear an alarm going off elsewhere in the house. We didn’t test interconnectivity features in our review since we tested single alarms individually, so check specifications when shopping if this feature sounds useful.
Smart home hub support: If you want to integrate your smoke alarm with the rest of your home, consider whether it is supported by a major smart home hub. The Nest Protect is obviously tied to the Nest ecosystem, but Alexa, SmartThings, and HomeKit options are also available. Note that we had lackluster results with several of these hooks—and even if you do connect the alarm to your smart home hub, the ultimate usefulness of this connection can be limited.
That said, when paired with a smart thermostat, some smart smoke alarms can trigger the thermostat to shut down your HVAC system, so that smoke isn’t pulled into your ventilation system and circulated all around your home.
What other smart smoke detectors has TechHive reviewed?
Our X-Sense Mini review reports that those sensors can wirelessly interconnected, and you can buy a 3-pack for less than $60 on Amazon. But they don’t have any smart features beyond that; there’s no smartphone app, for instance, and the sensors don’t connect to your Wi-Fi network. That means they can’t alert you to a fire if you’re away from home. It’s also worth noting they won’t detect the presence of dangerous levels of carbon monoxide.
You’ll find that street prices have dropped considerably since we published our First Alert Onelink Safe & Sound review. It offers plenty of whizbang features, including the ability to operate as an Apple AirPlay 2 speaker–or an Alexa-powered smart speaker–and it’s HomeKit compatible. But it remains the most expensive smart smoke and CO alarm we’ve reviewed. If you want HomeKit compatibility for less dough, check out our First Alert Onelink review. It keeps that feature but drops the music-streaming and smart speaker elements.
Author: Christopher Null, Contributor, TechHive
Christopher Null is an award-winning technology journalist with more than 25 years of experience writing about and reviewing consumer and business tech products. Previously, he served as Executive Editor for PC Computing magazine and was the founder and Editor in Chief of Mobile magazine, the first print publication focused exclusively on mobile tech. In addition to covering a wide range of smart home gear for TechHive, he is a frequent contributor to Wired, This Old House, and AAA’s Via Magazine.