The 7 Best Carbon Monoxide Detectors of 2021

Breathe easier knowing you're safe at home

Our editors independently research, test, and recommend the best products, and articles are reviewed by healthcare professionals for medical accuracy. You can learn more about our review process here. We may receive commissions on purchases made from our chosen links.

Our Top Picks
Gives you the ability to test the alarm from your phone and receive a full report when it's done.
Functional and reliable, you just simply plug it in and you’ve got protection.
Has an easy-to-read digital display that constantly displays carbon monoxide levels.
Super lightweight, it's perfect for taking with you on the go.
Easy to install, runs with just two AA batteries, and is compatible with certain smart home devices.
You can use this as another Alexa device or speaker to play music.
Senses natural gas, methane, and propane, and illuminates when it reaches hazard level.

Installing (and maintaining) carbon monoxide detectors in your home is one of the best ways you can protect the health and safety of your family. Every year, according to the CDC, at least 430 people die of accidental carbon monoxide poisonings and around 50,000 people visit the emergency room due to accidental carbon monoxide poisoning.

“Carbon monoxide poisoning is the second leading cause of poisoning in the home—that’s how serious it is and common it is,” explains Chuck Roydhouse, retired professional firefighter and president of the Chimney Safety Institute of America. Carbon monoxide detectors are important because not all sources of the gas are obvious and the gas is impossible to detect on your own. “Carbon monoxide is colorless, odorless, and tasteless, without a carbon monoxide detector, you may not know you’re being exposed to carbon monoxide until it’s almost too late,” Roydhouse explains. 

The initial symptoms of carbon monoxide poisoning can also be mistaken for other illnesses. “[It] gives a lot of flu-like symptoms—headache, nausea, vomiting, dizziness, shortness of breath, and fatigue—so, when you have CO poisoning symptoms in the winter, you may simply assume you’ve got the flu,” he continues.  

This is especially true, he says because the most common source of carbon monoxide inside the home comes from home heating systems, which are used in winter—a time of year that also happens to be flu season. The biggest risk of carbon monoxide poisoning in the home comes from gas and wood burning appliances, such as furnaces, gas ovens, stoves, water heaters, and gas-powered clothes dryers. Other potential sources are "powered by internal combustion engines such as portable generators, cars, and lawn mowers," says Karla Crosswhite-Chigbue of the CPSC (U.S. Consumer Product Safety Commission).

Portable generators are especially relied on during hurricane season, with the NOAA (National Oceanic and Atmospheric Administration) predicting that "the average Atlantic hurricane season will reflect more storms." However, portable generators have the ability to expose individuals to increased risk of carbon monoxide poisoning and fire.

The good news is that carbon monoxide detectors are relatively affordable, reliable, and easy to set up.

Here are the best carbon monoxide detectors on the market today.

Best Overall: Google Nest Protect Smoke and Carbon Monoxide Alarm

Google Nest Protect
  • Carbon monoxide/smoke detector hybrid

  • Compatible with Google Nest Family

  • Phone connectivity

  • Available wired or battery

  • Easy set-up

  • Pricey

  • Smart features disabled in power outage

Whether you have a smart home or not, this hybrid smoke detector and carbon monoxide detector is the best on the market. It gives you the ability to test the alarm from your phone and it will send a full report to you when the test is complete. It will also remind you to test the alarm in case checking it slips your mind, and, if you get the battery one, it will let you know when its battery is running low.

The device connects to the entire Google Nest Family where you can control all your smart devices in one app. Best of all, it will notify you and 911 in the case of an emergency, even if you aren’t home. “As people get back into the routine of going back to work away from home, that's a nice feature to have,” says Roydhouse. “[It] prevents you from going home and being exposed and it allows you to take action if pets, children, or elderly folks are in the home.”

Charge Type: Wired or Battery | Added Features: Smoke detector, Google Nest connectivity, smart features, phone connectivity, remote testing

Best Budget: FIRST ALERT CO605 Plug-In Carbon Monoxide Detector

First Alert CO605 Plug-In Carbon Monoxide Detector
  • Affordable

  • Easy to use

  • Very loud alarm

  • Small and compact

  • Only 8 hours of battery

This carbon monoxide detector may be no frills, but it’s functional, reliable, and super simple to use. Simply plug it in and you’ve got yourself protection—with a seven year limited warranty too. It’s also incredibly affordable, and if you want, you can even buy a pack of three to make sure you have enough for every floor of your house. It plugs in for power, but also comes with a battery in case of a power outage.

Charge Type: Plug-in, battery backup | Added Features: None

Best Plug In: Kidde Nighthawk

Kidde Nighthawk Plug-In AC/DC Carbon Monoxide Alarm Detector
  • Reliable

  • Easy-to-read digital display

  • Portable from room to room

  • Plug-in with backup battery and extra cord

  • No smart features

When it comes to a plug-in carbon monoxide detector, you want three things—dependability, ease of use, and accuracy—and this one has all three. It’s got an easy-to-read digital display that constantly displays carbon monoxide levels, as well as a button to recall the highest peak level of carbon monoxide in your home. It also has the ability to be unplugged and moved to a new room when you need a quick reading and it won’t go out in a power outage, all thanks to its backup battery.

Charge Type: Plug-in | Added Features: Quick read digital display, backup battery, peak level button

What the Experts Say

“What makes Kidde Nighthawk great is that they’re affordable and fast. Anybody could buy one for around $30 and have it installed in about two to three minutes. All you really have to do is open the packaging, add a 9V battery, and plug the detector in.” —Chuck Roydhouse is a retired professional firefighter, President of CSIA (Chimney Safety Institute of America).

Best Portable: FORENSICS DETECTORS FD Car, Vehicle, Aircraft CO Detector

Forensics Detector Car, Vehicle, Aircraft Carbon Monoxide CO Detector
  • Portable and super lightweight

  • Highly accurate

  • Fast read and alarms

  • Really easy to use

  • Pricey

  • Batteries don’t last that long

Weighing only two ounces, this super lightweight, portable carbon monoxide detector is perfect for taking with you on the go. You can check for exhaust leaks in your car, airplane, or you can simply use it on trips or for quick reads around your home. It is sensitive to carbon monoxide levels as low as nine parts per million (ppm), which is much lower than most household detectors.

Charge Type: Battery | Added Features: Portable

Best with Smoke Detector: FIRST ALERT Z-Wave Smoke Detector & Carbon Monoxide Alarm

 First Alert Z-Wave Smoke Detector & Carbon Monoxide Alarm
  • Easy to install

  • Compatible with some smart home systems

  • Two-in-one carbon monoxide and smoke detector

  • Affordable

  • Mediocre battery life

  • Smart home connectivity isn’t the most reliable

First Alert is one of the most reliable brands—and their two-in-one detector doesn’t disappoint. It’s super easy to install and it runs with just two AA batteries. It also works with certain smart home devices, including Ring and Samsung SmartThings, and allows for an in-app experience. Most importantly, it’s a reliable and accurate smoke and carbon monoxide detector that has a pretty loud alarm to alert you to a problem.

Charge Type: Battery | Added Features: Tamper-resistant battery door

Best with Smart Features: FIRST ALERT Onelink Safe and Sound

Onelink Safe & Sound
  • Built-in Bluetooth speaker

  • Alexa-enabled

  • Comes with nightlight

  • App can crash

  • Not the easiest to install

Not only is this carbon monoxide detector also a smoke detector, but it also comes with smart features, including built-in Alexa, a Bluetooth speaker, and the ability to send push notifications right to your phone. In other words, you can use this as another Alexa device or speaker to play music.

Charge Type: Wired | Added Features: Nightlight, Alexa-enabled, Bluetooth speaker

Best with Gas Detector: First Alert Explosive Gas and Carbon Monoxide Detector

FIRST ALERT Combination Explosive Gas and Carbon Monoxide Alarm
  • Small and compact

  • Plugs into standard outlet

  • Battery backup for power outage

  • Detects gases and carbon monoxide

  • Blocks other outlet from use

  • Battery backup doesn’t last long

If you’re worried about more than just carbon monoxide, this detector is the safety device you need to monitor for any hazardous gases in your home. Not only does it detect carbon monoxide, but it will also sense natural gas, methane, and propane as well. It’s also fairly compact and plugs straight into your outlet, though it is worth noting that it usually blocks the other outlet from use. In addition, it’s got a 9V battery backup in case of a power outage and a digital display that will illuminate with the hazard level when the alarm is activated. You can also click any button to display current hazard levels.

Charge Type: Plug-in with backup battery | Added Features: Gas detector, Digital display

Final Verdict

If you have a smart home—and don’t mind the added expense—then the Google Nest Protect Smoke and Carbon Monoxide Alarm (view at Amazon) is the way to go. It will remind you when it’s time for a test, alert you to low-battery, and seamlessly alert you on your phone in the event of a problem. But if you want something a little simpler and more affordable, experts love the Kidde Nighthawk Carbon Monoxide Detector (view at Amazon) for its reliability, durability, and ease of use.

What to Look for in a Carbon Monoxide Detector


Of course, the most important thing is that your carbon monoxide detector is accurate. Pay close attention to how sensitive it is and what levels of carbon monoxide it can detect. Some detectors are much more sensitive to low levels of gas than others, which could save you precious time in an emergency. 

Power Source

Carbon monoxide detectors can be wired, battery-powered, plug-in, or some combination of both. The choice of what you get is up to you—it’s mostly a matter of preference. However, there are some things to keep in mind. If your detector is wired or plug-in, you’ll want to look at devices that have a battery backup power source in case your power goes out because that’s often when leaks go undetected. If you opt for a battery-powered device, make sure you check the battery levels frequently to make sure your detector is still functioning properly. 

Crosswhite-Chigbue recommends, "The best way to protect your family is by installing battery-operated CO alarms or CO alarms with battery backup in your home outside separate sleeping areas and on each floor of your home." Proper maintenance shouldn't be taken lightly either since CO alarms are made to go off before carbon monoxide reaches fatal levels, "Replace batteries in alarms at least once every year. Test alarms every month to make sure they are working," she says.

Ease of Use

Ultimately, if your carbon monoxide detector is difficult to use, you aren’t going to use it. Make sure that it installs easily and is easy to use when it comes time to schedule a test, check battery levels, or read carbon monoxide levels. 

Added Functionality

If you want to keep your family safe, you might want to look for a carbon monoxide detector that comes with additional features. For example, some are two-in-one devices that function as smoke detectors, while others can sense other hazardous gases. 

You might also be interested in having some smart features, especially if your home is already connected to other smart features. Plus, some will send you alerts right to your phone or allow you to schedule tests while you’re away. If these features appeal to you, look for detectors that pair with Google Home, Alexa, or that come with phone connectivity.  

Frequently Asked Questions

  • Where’s the best place to put a carbon monoxide detector?

    Carbon monoxide detectors should be placed on each level of your home and near your bedrooms. You’ll want to install them at least five feet from the ground on the wall. If you have a garage, you should place one near that area as well, especially if it adjoins the house. 

    “A lot of times, even if you start a car with the garage door up and you back the car out almost immediately, you’ll have residual carbon monoxide lingering in the garage space,” explains Roydhouse. “If you’re heating your home with a forced air system, when that cycles on it creates negative pressure that will pull air from around a leaky door… [and] it can potentially pull carbon monoxide in and push it through your duct work, distributing it throughout your home.”

    Do not put the detector inside the garage though—just in the area of the house near it. You also shouldn’t put your detectors near the furnace room or any fuel burning appliances.

  • How long do carbon monoxide detectors last?

    Carbon monoxide detectors generally last somewhere between five to seven years, though it depends on which type you buy. Be sure to check the owner’s manual to be sure. Regardless of how long it lasts, though, you’ll want to get in the habit of checking on it monthly to make sure it’s still working and you’ll want to change the batteries every six months or so. 

    “Check smoke detectors and carbon monoxide detectors when you change the clocks in the fall and the spring,” Roydhouse says. “If you change the batteries every six months when you spring forward and fall back, you should be in pretty good shape.”

  • Can a carbon monoxide detector detect a gas leak?

    No, most simple carbon monoxide detectors cannot detect a gas leak. 

    However, there are some specialized gas leak detectors that detect explosive gases (such as natural gas, propane, or methane) that also detect carbon monoxide—but you need to get this kind of specialized, hybrid device like the First Alert Explosive Gas and Carbon Monoxide Detector (view at Amazon).

What the Experts Say

“You don’t need anything overly expensive or fancy. The things that drive the costs up are different features, but they all are required to have a minimal standard of how they work. So if you’re looking for something simple that will alarm you when there’s a problem, any one of the options will work, no matter what the price point.” —Chuck Roydhouse is a retired professional firefighter, President of CSIA (Chimney Safety Institute of America)

Why Trust Verywell Health?

As an experienced health and science reporter, Simone Scully understands the importance of picking thoroughly researched products to keep your family safe and healthy.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Carbon Monoxide (CO) Poisoning Prevention. Updated January 19, 2021.