Smoke alarms generally have one purpose and that's to alert you of a fire. But did you know that you can make your humble abode even safer thanks to smart smoke and carbon monoxide (CO) alarms? Not only do they send notifications to your phone, but most of them are pretty easy to install, too. Whether it's smart water leak detectors or smart thermostats, turning your living space into a smart home is both safe and convenient.
We put the best smoke detectors and monitors on the market through their paces to find which one you should buy, and we found the Nest Protect(available at Amazon for $119.00) to be the top choice. Between the easy installation and intuitive app, there's a lot to love. But if you're looking for something a little more barebones, don't worry, we've got plenty of other options for you, too.
These are the best smart smoke and carbon monoxide detectors and monitors we tested ranked, in order:
Nest Protect Smoke and Carbon Monoxide Alarm
Kidde Smart Smoke and Carbon Monoxide Alarm
First Alert 2-in-1 Z Wave Plus (second gen)
Abode Smoke Alarm Monitor
First Alert Onelink Safe and Sound (Hardwired)
X-Sense Wi-Fi Smoke Alarm
First Alert Onelink Smart Smoke + Carbon Monoxide Alarm (Battery-Powered)
The Nest Protect Smoke & Carbon Monoxide Alarm is a reasonably priced smart detector with ample functionality. The 2nd generation Nest Protect comes in both battery operated and hardwired models, and instead of traditional photoelectric or ionization technology, this alarm uses a split-spectrum sensor to monitor for both smoldering and fast-burning fires. In addition to sending you push notifications when it detects smoke or carbon monoxide, it offers voice alerts, a night light option, low-battery alerts, and a monthly self-test feature.
It takes about five minutes to set up the Nest Protect, and the process is impressively thorough, asking you for the detector location, as well as your self-testing and night light preferences. The Nest app is intuitive and easy to use on both iPhones and Androids—not surprising given that Nest is a leader in the smart home space. In our tests, the smartphone notifications arrived around 30 seconds after the alarm sounded, which wasn’t the fastest, but we liked that the alerts specify whether it’s a just a “Heads Up” (a little bit of smoke) or a genuine “Emergency” (get out of the building).
Overall, we’d feel safe with this smart smoke alarm protecting our homes, and there are thousands of positive reviews that testify to the superior performance of this product. Plus, it’s significantly less expensive than other comparable smart smoke detectors with similar features.
How We Test Smart Smoke Alarm and Carbon Monoxide Detectors
I’m Rachel Murphy and I cover mart home for Reviewed. From household linens to smart home gadgets, I've been doing product testing for a number of years. And, like most people, I want to keep my humble abode as safe as possible. That's why I dived back into the world of smart home to test the best smart smoke and carbon monoxide detectors available today. My work is built up Camryn Rabideau, a freelance contributor for Reviewed.
To test these smoke detectors, we first installed and synced each device with its app. After the initial setup, we ran a “self-test” on each model and navigated around both the iOS and Android versions of the apps to assess usability.
Finally, we used aerosol-sprayed smoke and tapered candles to set each alarm off. We did this multiple times for every model—once while the phone was connected to Wi-Fi and once when it was not—to see if there was a difference in how quickly notifications were delivered. During these tests, we also evaluated the smart home integration, quality/volume of the alarm, quality of the smartphone notifications, and ease of silencing each detector. Other factors we took into account were interconnectivity, app connectivity, and perceived reliability.
What You Should Know About Smart Smoke Carbon Monoxide Detectors and Monitors
What is a Smart Smoke Alarm?
Like most smart home devices, smart smoke and carbon monoxide detectors connect to your home’s Wi-Fi and, subsequently, your smartphone. In other words, they go a step further than your traditional smoke alarm. This is the main appeal of smart smoke detectors, but some high-end models include additional “smart” features like voice controls via Alexa, weather updates, voice alerts, customizable night lights, and more.
What is a Monitor?
Monitors essentially “listen” for your smoke and carbon monoxide alarm, and if they hear it going off, they send a smartphone notification to let you know. They're typically installed in proximity to your existing smoke detectors—some plug into an electrical outlet while others are battery operated—and they’re connected to your home Wi-Fi network. However, they don’t allow you to silence your smoke alarms and they won’t save you from 2 a.m. low-battery chirps.
Why Does it Make Sense for Smoke Alarms Be "Smart"?
Smoke detectors are a perfect example of a device that benefits from smart functionality. Why? Standard detectors have a few major shortcomings, mainly that they’re not all that useful when you’re not home. If your detectors aren’t connected to the local fire department (which most are not) and a fire starts when no one is home, the alarms simply beep away to no avail. Plus, that’s not to mention the dreaded 3 a.m. low-battery chirps—we could all live without those.
Smart smoke detectors solve both these issues, as they send you smartphone notifications when the alarm goes off and give you a heads up when the battery is low. The "smart" functionality can not only give you peace of mind while you're away from home, but it can also save you time and energy when it comes to replacing those pesky smoke alarm batteries. Plus, if you ever burn popcorn and accidentally set off your smart alarm, you can quickly silence the detector from its app, saving you from having to grab a chair and climb up there to manually silence it.
Photoelectric vs. Ionization Smoke Detectors
There are three types of smoke detectors you can buy: photoelectric, ionization, and dual-sensor. These terms refer to the technology used to sense smoke.
Photoelectric smoke detectors have a light source that’s pointed into a sensing chamber, and when smoke particles enter the chamber, they reflect light onto the sensor, triggering the alarm. This type of smoke detector is more efficient at sensing fires that begin with a long period of smoldering, according to the U.S. Fire Administration.
On the other hand, ionization smoke detectors have a small amount of radioactive material between two electrically charged plates. This ionizes the air (hence their name) and creates a current that flows between the plates. If smoke particles enter the chamber, it will disrupt the current and activate the alarm. This style of smoke detector will typically sense flaming fires more quickly.
There are also dual-sensor smoke detectors, which use both photoelectric and ionization technology. For comprehensive protection in your home, the U.S. Fire Administration actually recommends dual-sensor detectors, which efficiently monitor for both types of fires.
There’s always a potential privacy risk involved when you use internet-connected devices at home. To help safeguard your smart home, there are some steps you can take. First, look for devices that offer two-factor authentication, which sends a code to your mobile device to verify it’s really you. That way, if someone tries to hack into your account, you will receive an alert and can quickly take care of the problem. Many devices also allow you to activate email or other push notifications in the settings to alert you if someone has logged on.
Additionally, make sure to use a unique, strong password composed of multiple characters, numbers, and letters for each of your smart home accounts. Data breaches feel like the norm as of late, making it all the more important to use different passwords across multiple websites and apps.
Other Smart Smoke Carbon Monoxide Detectors And Monitors We Tested
Kidde Smoke and Carbon Monoxide Detector
Second to the Nest Protect, the Kidde Smoke and Carbon Monoxide Detector is one of the smartest we’ve tested. The device , available exclusively at Home Depot, offers a full spread of smart home functionality with Amazon Echo and Google Home, is simple to set up and use, and should last a decade before you need to replace it.
Installation requires existing wiring (120V AC). As long as you don’t run into any snags with your wires, the physical installation process is simple and takes about five minutes (don’t forget to flip off the breaker before you begin). A built-in lithium backup battery (estimated lifespan of 10 years) ensures that the monitor remains on during a power outage.
Like the Nest Protect, the Kidde detector uses voice warnings to alert you of fire or carbon monoxide instead of a traditional alarm tone. The alerts aren't as detailed as what's available on the Nest Protect, which tells you exactly what room or area of the home the problem is in. But the Kidde alerts are loud, easy to understand, and more calming than the blaring sounds put out by most other detectors. The device can also be interconnected with other Kidde smoke and carbon monoxide detectors for whole-home coverage.
Alerts are sent quickly in a variety of ways (push, SMS, and email). Voice assistants Alexa and Google Assistant can also alert you to smoke or carbon monoxide-related issues through Amazon Echo and Google Nest smart speakers and displays. You can also use either smart assistant to check the status of your detector. One thing that’s a bit unusual about the smart assistant setup is that you have to enable permissions between the detector and Alexa and/or Google Assistant in the Kidde app (in addition to adding the device to your smart home ecosystem).
The Kidde Smoke and Carbon Monoxide Detector may not be as feature-filled as the Nest Protect, but the device gets closer to achieving Google's helpful emergency smarts than most, and offers more versatility should you switch to Alexa. Kidde is also the more affordable of the two detectors, making it a mighty fine choice for anyone who doesn't want to pay a premium price for Nest.
First Alert 2-in-1 Smoke and Carbon Monoxide Alarm (second-gen)
The First Alert 2-in-1 Smoke and Carbon Monoxide Alarm (second-gen) is a good fit for smart homes with a Z-wave hub like the Ring Alarm or Samsung SmartThings. The detector, which runs on two included AA batteries, only connects over Z-Wave Plus, a low-frequency wireless signal that offers a broader coverage range and better connectivity than the first-gen Z-Wave alarm. To test the monitor, we paired it with the Z-wave-compatible Ring Alarm Pro base station. It took several attempts to add the device due to glitches in the Ring app, but forcing the app closed and reopening it multiple times did the trick.
The device detects smoke quickly, which triggers instantaneous push alerts to your phone and a loud, 85-decibel tone to start blaring from the detector. Base stations for Ring Alarms also double as sirens, which you can silence directly from the Ring app. There is no way to silence the detector from the app itself. This is one of the most frustrating aspects of the alarm, as you’ll always need a chair or ladder to reach up and silence it somehow.
The detector doesn’t work with Apple HomeKit or Google Home, but it is compatible with the Amazon Echo ecosystem. Supposedly the device can make announcements using Echo smart speakers and displays when the detector needs attention, but this feature did not work for us. However, between the push alerts and multiple alarm tones, it’s hard to miss any alarm events.
When you use the device with a Ring Alarm or Ring Alarm Pro base station (coupled with a paid Ring Protect Pro plan), emergency responders will be automatically notified by Ring's professional monitoring team when the device detects a problem at home. One advantage of pairing it with the Ring Alarm Pro, which has a built-in Wi-Fi router, is that it can keep the detector online even during a Wi-Fi outage. (The Ring Protect Pro plan is required to access the base station’s 24/7 internet backup service.)
Though it’s got a couple of setup and usability quirks, the First Alert 2-in-1 Smoke and Carbon Monoxide Alarm (second-gen) is a fantastic choice for smart homes reliant on Z-wave hubs.
The Abode Smoke Alarm Monitor gets top marks in terms of performance—it sends push notifications to your phone within seconds of hearing a smoke alarm go off and, unlike other monitors we tested, it also gives off a high-pitched siren of its own.
This battery-powered smoke alarm monitor is easy to install—you can either use screws or double-sided tape to mount the small unit on the ceiling near your existing smoke detectors. It’s also straightforward to pair with the associated app, which is intuitive and easy to use. You can quickly silence the monitor from the app, and we liked that this system sends out push notifications if it ever loses a Wi-Fi connection.
The major downside of this particular monitor is that it must be paired with the Abode Gateway, and the brand’s basic “Starter Kit” costs $199. However, if you already have the gateway or are interested in a DIY security system, this monitor would be a great choice.
If you’re looking for a smart smoke and carbon monoxide detector that has tons of functionality, the First Alert Onelink Safe & Sound is a good option that sends push notifications quickly. It also ha other features like a built-in Bluetooth speaker, customizable night light, and Alexa functionality.
During our testing, the Onelink Safe & Sound pushed out smartphone notifications as soon as the detector went off, and it was easy to silence alarms via the app. Both the voice announcements and speaker quality were impressive, but the Onelink app itself isn’t the best, crashing fairly frequently. Additionally, this smart smoke alarm was a challenge to install—it was nearly impossible to clip into the mount, and once you do get it in, it probably won’t come off.
Overall, this smart smoke and carbon monoxide detector is packed with smart features and does its main job well, alerting you immediately with push notifications if it ever goes off. However, it’s more expensive than others we tested, and a lot of the features that command its higher price seem kind of unnecessary. If you like the idea of using your smoke detector to play music or as an Alexa device, you can feel secure that this device will protect your home and family, but if the extraneous features don’t appeal to you, there are cheaper, equally reliable options, such as the Nest Protect.
The X-Sense Wi-Fi Smoke Detector is a compact, lithium battery-powered device that uses photoelectric sensors to detect smoke (but not carbon monoxide levels like others in our guide).
The device isn’t compatible with the Amazon Echo or Google Home ecosystems, but remote management is available in the TuyaSmart app for iOS and Android. The device doesn't have the intuitive features and helpful smarts of the Nest Protect, but the trade-off here is that it’s also one of the least expensive smoke detectors in our guide.
Some Amazon reviewers report difficulties connecting the device to Wi-Fi during setup. We didn’t have any connection issues (using a dual-band Eero Mesh Wi-Fi router), but the alarm does need a 2.4 GHz wireless network in order to work.
It took the X-Sense Wi-Fi Smoke Alarm several seconds longer to detect smoke than the Nest Protect, but alerts were sent quickly once the siren started to sound. The 85-decibel tone is loud enough to hear from a room over, but it is harder to hear if you’re across the house or in the garage. To remedy this, you can connect multiple X-Sense smoke alarms on the same Wi-Fi network, so that when one sounds, they all do. When the alarm goes off, a blinking red light on the alarm serves as a helpful visual clue.
In the X-Sense app, you can silence the alarm, view the alarm’s history, and review results from the device’s automatic self-checkups. One issue we experienced with that app is that it continued to show there was a fire danger after the smoke had cleared. It took a couple of minutes for the app to show that everything returned back to normal.
The alarm takes a CRR123A 3-volt lithium battery, which isn’t as common as the AA or 9V batteries you’ve probably got floating around your junk drawer. Low battery notifications are sent when it’s time to pop in a new one. Registering the device with X-Sense activates a seven-year warranty.
The X-Sense Wi-Fi Smoke Alarm falls short on features compared to other detectors in our guide, but it is one of the cheapest options.
First Alert Onelink Smart Smoke + Carbon Monoxide Alarm (Battery-Powered)
We had high hopes for the second generation First Alert Onelink Smoke and Carbon Monoxide Detector, but this model had many of the same problems as the original version. This updated alarm is now compatible with Android phones (the first generation wasn’t), but the app still crashes and the pairing process is still clunky and glitchy.
Further, we found this smoke and carbon monoxide detector had connectivity issues. Several times when we tested it via the app or set it off with artificial smoke, the app never even registered the action. We spoke with Onelink support to resolve these issues, and they noted the detector can have problems if it’s too far from the Wi-Fi router or if there’s interference from other appliances. Overall, we just don’t feel confident recommending this product, as its smart features don’t seem to perform reliably and may not let you know if there's an emergency when you're not home.
Camryn Rabideau is a full-time freelance writer and product tester with eight years of experience. She's been lucky enough to test hundreds of products firsthand, and her specialties include bedding and pet products, which often require help from her two dogs, three cats, and flock of rambunctious chickens.
Rachel Murphy is Reviewed's home editor. She holds a journalism degree from the University of Central Florida. Prior to joining the team, she worked as a freelance writer for publications like Insider and Mashable, and as an associate editorial producer for Good Morning America. Aside from smart home tech, her interests include food, travel, parenting, and home renovation. You can usually find her sipping on coffee at any time of the day.
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