10 Best Carbon Monoxide Detectors 2023

Rest easy with these picks from top brands like Kidde and First Alert.

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Better Homes & Gardens / David Hattan

While you likely already have smoke detectors covered, carbon monoxide detectors are equally important. Carbon monoxide is considered a “silent killer,” and for good reason.

According to Jim Koether, master electrician at Reliable Heating & Air and former volunteer firefighter, “carbon monoxide is odorless and invisible. You won’t know you’re being exposed to it unless you have a detector.”

Carbon monoxide detectors save lives daily, which is why it’s so important to get one that’s effective and durable. Warranty, power source, alert type, and detection type all play a part, and these factors helped inform our list of the best carbon monoxide detectors.

Amazon

This attractive, best selling model includes a backup battery, extension cord, and tabletop stand.

Some of the other monitors on our list can also detect smoke or gas.

Kidde is one of the most trusted brands in this space, known for creating incredibly dependable products. It’s no surprise that it produces the best carbon monoxide detector overall. You can install your new, sleek monitor in just a second: simply plug into a standard 120-volt outlet. In case of a power outage, there’s a 9-volt alkaline battery that will kick in.

With the included six-foot extension cord and tabletop stand, you can put the monitor on a table, counter, or shelf if you prefer. Unlike some of the other monitors on our list, this one exclusively looks out for carbon monoxide (no smoke or gas). But it does that very well. Upon detection, you’ll hear an 85-decibel alarm, while the digital LED display tells you how much carbon monoxide is in the air, updating every 15 seconds.

There’s a smart-hush button that you can use to test or quiet the monitor. With the latter, one push will silence it for eight minutes, giving you the opportunity to handle the issue if possible. The peak level memory lets you know the last time the device detected carbon monoxide or was tested.

Price at time of publish: From $35

Product Details: Detection Type: Carbon monoxide | Alert Type: Alarm | Dimensions: 6.06 x 3.75 x 1.75 inches | Power Source: Plug-in and backup battery | Warranty: 10 years

Amazon

There’s a pull-down action chart that tells you what to do in case the emergency alarm sounds.

It’s very short on features like interconnectivity or remote control sync.

You don’t need all the frills to be effective, which is exactly why this is our budget pick for best carbon monoxide detector. It looks for carbon monoxide with an advanced electrochemical sensor, which can accurately detect levels from anywhere in the room. When it locates a dangerous amount, the monitor will sound the 85-decibel alarm.

Panicking? Just pull down the action chart that will tell you exactly what to do next. The device is operated by a replaceable 9 volt battery that works even when there’s a power outage. You’ll notice audio and visual alerts when it’s time for a fresh one. Because the monitor runs on battery power, no real installation is required unless you want to take advantage of the optional wall mount.

To test the monitor, use the test/silence button. You should hear a 5-6 second alarm sequence. With a five-year warranty, the permanent sensor can last up to five years. The end-of-life chirp will give you a heads up when it’s time for a replacement.

Price at time of publish: $20

Product Details: Detection Type: Carbon monoxide | Alert Type: Alarm | Dimensions: 5 x 1 x 3 inches | Power Source: Battery | Warranty: 5 years

Amazon

This smart monitor is Alexa enabled and Apple HomeKit compatible. You can also connect it with other hardwired alarms in your home.

Although you can play music with the Safe & Sound, you can’t use it to play music on other Alexa devices.

A carbon monoxide detector that’s also a smoke alarm and a smart home? That’s definitely worth the splurge. The Onelink Safe & Sound is hardwired with photoelectric and electrochemical sensors, plus an omni-directional speaker.

It’s Alexa enabled and Apple HomeKit compatible, which means you can ask it via voice control to do all sorts of things: check the weather, call someone, read audiobooks, play music, etc. That said, you can’t use the Safe & Sound to play music on other Alexa devices. If you have multiple Onelink Safe and Sound monitors, you can use one to “drop in” on any of the others like an intercom.

Beyond the little luxuries, part of what makes this one of the best carbon monoxide detectors is that it can connect with the other hardwired alarms in your home. With the Onelink Home app, it can send you a message if danger is on the horizon (you’ll also hear the 85-decibel alarm and a voice alert naming the problem and location).

Another app perk is being able to adjust the brightness and usage of the monitor’s LED lights. Their purpose is twofold: to act as a nightlight in the dark and light your way in an emergency. You can even track carbon monoxide and battery levels. Though the warranty is for three years, it’s worth noting that the battery backup is for 10 years. Installation is easy—if you use the included AC adapter plugs, you don’t have to rewire after your old hardwired alarm. The unit itself will then explain the setup to you step by step.

Price at time of publish: $225

Product Details: Detection Type: Carbon monoxide and smoke | Alert Type: Alarm, app, and voice alert | Dimensions: 7 x 7 x 2 inches | Power Source: Battery | Warranty: 3 years

Amazon

The display shows both current and peak levels of carbon monoxide and explosive gasses. In addition to a button on the monitor, you can configure a remote to silence it.

It has a more dated look than many other carbon monoxide detectors.

At all times, this monitor is searching for unsafe levels of carbon monoxide and explosive gasses (natural, methane, and propane). On the display, you can see current and peak levels of both, which helps you stay in the loop and identify any concerning patterns. If it finds them, you’ll be alerted by an 85-decibel alarm. You can mute the alarm one of two ways: by using the silence/test button on the monitor or configuring a standard remote control for use from afar.

It can be set up in just one step by plugging into any AC outlet. You can either keep it against the outlet or use the long attached wire to put it on a nearby surface for greater visibility. If this is your plan, just keep in mind that its appearance is more dated than many of the other detectors we’ve featured.

There’s also a 9-volt battery so if power goes off, you’re still in the know. If the battery needs to be replaced, you can do so via the easy-to-access battery drawer. You’ll know it’s time to replace your unit, not just the battery, when you hear the end-of-life timer. This shouldn’t be for a long time, considering the 10-year warranty.

Price at time of publish: $54

Product Details: Detection Type: Carbon monoxide and gas | Alert Type: Alarm | Dimensions: 7.25 x 4.25 x 9.06 inches | Power Source: Plug-in and backup battery | Warranty: 10 years

Amazon

The monitor hangs off a lanyard so it’s easier to keep track of. In addition to carbon monoxide, the screen displays the temperature and humidity level.

The one-year warranty is the shortest on our list.

In addition to being able to detect carbon monoxide with an electrochemical sensor, this device can also tell you the temperature and humidity level. The numbers are displayed on the color HD 1.9-inch screen. Data is refreshed every two seconds, so you always know what’s happening, when it’s happening.

When the carbon monoxide hits over 50 ppm (parts per million), you’ll hear the alarm loud and clear. The pint-sized detector is on a lanyard, providing maximum portability. This is helpful when you’re traveling to a hotel, Airbnb, or campsite.

The 1000 mAh battery is chargeable via a USB, and can operate for 50 hours straight once fully charged. This is admittedly less than some of the other best carbon monoxide detectors run on battery, but makes sense given the size and portability. The other thing to consider is the warranty. At one year, it’s shorter than all the others on our list.

Price at time of publish: $40

Product Details: Detection Type: Carbon monoxide, smoke, and gas | Alert Type: Alarm | Dimensions: 2 x 0.67 x 3.35 inches | Power Source: Battery | Warranty: One year

Amazon

You’re able to connect up to 18 compatible devices. If there’s danger, every alarm in your home will sound versus just one.

The side battery compartment makes it tricky to open and replace the battery.

This monitor pulls double duty, able to sense carbon monoxide (with an electrochemical sensor) and smoke (with an ionization sensor). If they notice anything, the relevant indicator light will turn on while the 85-decibel alarm issues a warning. Installation is fairly easy, with a quick plug-in power connector to secure the monitor to your hardwiring. It will automatically test its functionality so you know it’s ready to go. With the warranty, you’re covered for 10 years.

Although it’s hardwired, there’s also a 9-volt backup battery so your home is protected even during a power outage. If the battery is low, you’ll hear a chirp. There’s a large, easily noticeable button that’s for both testing the detector and silencing an alarm or low battery warning. If you do need to replace the battery, there’s a tamper resistant compartment on the side—though this can be surprisingly tricky to maneuver. The universal mounting brackets are also tamper resistant.

An especially valuable feature is its compatibility with other BRK or First Alert detectors, which means that if smoke or carbon monoxide are detected, every alarm will sound instead of just the one in the affected area. You can connect up to 18 compatible devices—12 detectors and six other devices like bells or door closers. There’s also a latching arm indicator, which can immediately identify the detector that sensed the danger.

Price at time of publish: $39

Product Details: Detection Type: Carbon monoxide and smoke | Alert Type: Alarm | Dimensions: 5.6 x 5.6 x 1.9 inches | Power Source: Wire and backup battery | Warranty: 10 years

Amazon

This monitor detects both carbon monoxide and smoke, and also acts as a nightlight. When something is wrong, you’re alerted via pulsing light, voice announcement, and phone notification.

Despite being able to last for 10 years, it only has a two year warranty.

What can’t Google do? In addition to all its other technological accomplishments, the brand also makes one of the best carbon monoxide detectors. When the Nest Protect lights up, it’s in one of five colors: blue when it’s first active, green when it’s been tested, yellow when there’s a little smoke or carbon monoxide, pulsing red when there’s a dangerous amount of smoke or carbon monoxide, and white when you walk under it in the dark as a nightlight.

If something is wrong, in addition to the pulsing red light, the Nest Protect speaks up in a friendly, human voice warning you and telling you where the problem is. It also sends a message to your phone (ditto if the batteries are low) and if there’s not actually an issue, you can silence the monitor on the Nest app.

The only downfall is that although the monitor can last for up to ten years, it only has a two-year warranty. This is the second shortest warranty on our list, and significantly lower than the average.

Price at time of publish: $100

Product Details: Detection Type: Smoke and carbon monoxide | Alert Type: App, voice alert, and light | Dimensions: 5.3 x 1.5 x 5.3 inches | Power Source: Battery or wire | Warranty: Two years

Walmart

It has a thorough alert system including LED warning indicators, a beeping alarm, and an end-of-life announcement. It also has a 10 year warranty.

You can’t connect this monitor to other ones so that alarms will sound everywhere if one area is affected.

This multi-tasking monitor is able to detect both smoke and carbon monoxide at the same time, with a photoelectric sensor for the former and an electrochemical sensor for the latter. It runs on batteries, with two AAs included, so it stays on even during a power outage and you can bring it with you while traveling.

The monitor is constantly performing self-checks to make sure it’s operating well (though you should still do manual push tests) and will let you know when it's reaching the end of its life by literally announcing “replace alarm.” This will likely occur at the end of the 10-year warranty. There are three LED warning indicators: green is normal, amber represents an operating error, and flashing red means there’s smoke or carbon monoxide.

When the 85-decibel alarm sounds, you’ll hear three long beeps every 1.5 seconds if the monitor detects smoke and and four quick beeps every five seconds if it detects carbon monoxide. There’s a hush button that will silence the alarm for eight minutes, in case something like burnt cookies triggers it. Note that you cannot interconnect other monitors with this one, so you’ll only hear the alarm in the affected areas.

Price at time of publish: $45

Product Details: Detection Type: Carbon monoxide and smoke | Alert Type: Alarm | Dimensions: 2.62 x 8 x 7.17 inches | Power Source: Battery | Warranty: 10 years

Amazon

This is one of the most attractive monitors on the market. It shows the temperature as well as the carbon monoxide concentration.

Only the temperature is on constant display.

Part of what makes this one of the best carbon monoxide detectors is its surprisingly stylish design—it looks less like a monitor and more like a modern alarm clock. You can choose whether you want to set it on a surface or mount it on your wall. The backlit digital display shows the temperature at all times, and of course it can also show the carbon monoxide concentration.

Another plus is that you never need to change the batteries (or worry about a power outage), thanks to the built-in 10-year lithium battery. With a warranty of 10 years, the monitor basically has a lifetime warranty.

Using an electrochemical sensor, it accurately detects carbon monoxide better than any other kind. If the monitor detects too much carbon monoxide, an 85-decibel alarm will sound with a pattern of four beeps and a pause. One beep every minute means that the battery is low and five beeps every minute means that the monitor is at the end of its life. There’s also a button to silence or test the alarm whenever you want.

Price at time of publish: $35

Product Details: Detection Type: Carbon monoxide | Alert Type: Alarm | Dimensions: 0.94 x 4.75 x 2.63 inches | Power Source: Battery | Warranty: 10 years

Amazon

If you lose power, the backup battery will kick in. The plug has an attached wire so you can put the monitor wherever you want.

The monitor doesn’t have a built-in stand, so when it’s away from the outlet, you’ll need to pick it up to see the display.

With the backlit digital LED display, you can see the level of carbon monoxide in parts per million, as well as the level of power that’s available, so you’re always informed. In addition to the 85-decibel alarm that goes off when significant levels of carbon monoxide is detected, the monitor has a test and silence button. It also has a seven-year limited warranty, and when it’s nearing the end of its life, a three-chirp alarm will tell you when you need to get a new one.

The plug is attached to a wire so the monitor itself can be located elsewhere than in front of the outlet, which could make detection easier. That said, there’s no built-in stand that will keep it up, so you won’t always be able to see the display.

If you lose power, the backup battery (you’ll receive two AAs) will kick in and take over for the plug. You’ll know it’s working because the display will light up when power comes back. To make sure it’s activated, press and hold the test button. While the battery will do the job for a little while, it’s not meant to work in the long-term. You’ll see and hear low battery signals when it’s time for a replacement, and there will also be a signal when the battery has been removed.

Price at time of publish: $32

Product Details: Detection Type: Carbon monoxide | Alert Type: Alarm | Dimensions: 3.4 x 1.7 x 5 inches | Power Source: Plug-in and backup battery | Warranty: 7 years

Though on the basic side, we found the Kidde Carbon Monoxide Detector to be the overall best carbon monoxide detector because of its strong reputation, sleek appearance, extension cord, and tabletop stand. Our budget pick is the First Alert CO400 Carbon Monoxide Detector because it’s battery operated, meaning it won’t be impacted by power outages, and there’s a pull-down action chart that tells you what to do if there’s an emergency. The First Alert Onelink Safe & Sound is our top splurge pick because the smart monitor is Alexa enabled and Apple HomeKit compatible. You can also connect it to the other hardwired alarms in your home.

It may sound obvious, Koether says, but a warranty is important “in case of any malfunctions.” Unlike some other products, your carbon monoxide detector must always be in tip-top shape. Looking at the warranty can also give you a good idea of how long a monitor typically lasts. The best carbon monoxide detectors typically have seven to 10 year warranties.

There are three main power sources for carbon monoxide detectors: wire, plug-in, or battery. Koether recommends going with the wire or plug-in with a backup battery. This is because “if the power is off, you have full power with the battery, and when you have power, it’s using that instead of draining the battery.”

The best carbon monoxide detectors, if not all of them, use loud noises to get your attention. Usually this is an 85-decibel alarm, though as smart monitors the Google Nest Protect and First Alert Onelink Safe & Sound use voice alert and app messages as well. Having the app can act as an extra layer of insurance in a way, because you can still react even if you’re not home.

Of course, carbon monoxide detectors are on the lookout for carbon monoxide, but some also protect you from explosive gas (like the First Alert Combination Explosive Gas and Carbon Monoxide Alarm) or smoke (like the Kidde Smoke & Carbon Monoxide Detector). Which one you prefer may be a matter of which model you like best in general, or what you already have in your home that doesn’t need to be replaced any time soon.

Both are effective, but if you’re able to choose, go for the ceiling detector. According to Koether, “a ceiling monoxide detector might be a better placement because carbon rises and tends to gather on the ceiling.” Bonus: It’s also harder to tamper with, making it inherently safer.

Carbon monoxide detectors should be on every floor of your home, (including the basement), “near utility closets where the furnace or water heater might be.” Koether also says you should put them in the garage area. Other effective places include outside each bedroom or in the hallway and living room. Heads up that putting them near a fireplace, bathroom, or kitchen could cause a false alarm.

For standard options like the First Alert Combination Explosive Gas and Carbon Monoxide Alarm or First Alert BRK SC9120FF Hardwired Smoke and Carbon Monoxide Detector, you can expect to spend anywhere between $30 and $60. Smart detectors, on the other hand, can go into the low three figures. The First Alert Onelink Safe & Sound is $278 and the Google Nest Protect is $120.

“You want one on every floor at minimum,” explains Koether, “but every building is different.” The general rule of thumb is that the larger your home is, the more you’ll need. When in doubt, remember that you’ll never regret adding more than necessary.

Typically, Koether says they last between eight and 10 years. You can check the manufacturer guidelines to find out for sure. The warranty can give you a good idea as well. Regardless of what the manufacturer says though, when you hear the end-of-life chirp of your monitor, it’s time for it to go.

Quincy Bulin is a writer who covers products and home topics, making this story the ideal intersection of her work. To find the best carbon monoxide detectors, she conducted hours of research and consulted Jim Koether, master electrician at Reliable Heating & Air and former volunteer firefighter.