The 10 Best Carbon Monoxide Detectors of 2023

Protecting your home from the dangers of carbon monoxide (CO) isn't always top of mind. But CO is a deadly, odorless, and colorless gas that can quickly cause illness—headaches, dizziness, nausea, shortness of breath, and confusion—or death. Installing a carbon monoxide detector is one of the most effective ways to detect dangerous levels of carbon monoxide in your home before it's too late.

"CO detectors are devices connected to an alarm control unit having a sensor that responds to carbon monoxide," explains Diane Haithcock, standards program manager at UL Standards & Engagement (ULSE). "These alarms are detectors that incorporate a sensor, control components, and an alarm notification appliance in one unit."

When shopping for a carbon monoxide detector, it's important to look for UL-listed products. This means the product has been tested and certified by Underwriters Laboratories (UL), an independent safety science company. You should also be aware that CO detectors are powered by batteries, plug-in AC adapters, or hardwired into your home's electrical system. Keep in mind that some models are dual-function detectors, which also detect smoke.

To help you find the best carbon monoxide detector for your home, we spoke with health and safety experts and scoured the market for the best options available on the market today.

Our Recommendations

Best Overall: First Alert CO710
Best Budget: Kidde 9CO5-LP Carbon Monoxide Detector
Best Portable: Klein Tools ET110 Carbon Monoxide Tester and Detector
Best Plug-In: Kidde Nighthawk Carbon Monoxide Detector
Best Battery-Powered: X-Sense CD07 Carbon Monoxide Detector Alarm
Best Hardwired: Kidde KN-COPE-IC, Hardwire Carbon Monoxide Alarm with Digital Display
Best with Smoke Detector: First Alert Hardwired Smoke and Carbon Monoxide Detector
Best Smart: Google Nest Protect
Best Digital Display: Kidde Plug-In Carbon Monoxide Detector with Digital Display
Best Compact: X-Sense Carbon Monoxide Detector Alarm with Digital LCD Display

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Why We Like It: The 10-year battery and digital display make this CO detector an impressive choice for long-term protection.

It's Worth Noting: While it has a 10-year lifespan, you'll have to check it periodically to ensure that the battery is in good shape.

The First Alert CO710 Carbon Monoxide Alarm is an excellent choice for long-term protection. Chosen as our overall best carbon monoxide detector, this alarm is equipped with a 10-year lithium battery—no worrying about changing the batteries each year or power failure. The digital backlit display makes it easy to read and check the current and peak levels of carbon monoxide in your home.

Rest assured, knowing that the alarm is loud enough to be heard throughout the house and meets UL standards—the highest safety requirements in the industry. It’s also equipped with a temperature reading to monitor the ambient temperature in the room. There's no installation necessary, and at just 5 inches long and 3 inches tall, this alarm fits nicely on even the smallest table or shelf.

Price at time of publication: $45

Product Details:

Sensor Type: Carbon monoxide
Power Source: Battery
Digital Display: Yes
Interconnectivity: No
Features: Digital backlit display, 10-year battery, current and peak CO readings, ambient temperature reading

kidde-battery-powered-carbon-monoxide-detector

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Why We Like It: An affordable option with simple features, this detector is backed by a 10-year limited warranty.

It’s Worth Noting: The seven-year battery life is lower than that of some other models.

Kidde is a trusted name in home safety, and its carbon monoxide detector is an excellent budget-friendly option. The simple, yet effective, 9CO5-LP Carbon Monoxide Detector has a single button to test and silence the alarm, LED lights that pulse green while in standby mode, and a loud 85-decibel horn that sounds if CO levels reach dangerous levels. Its battery-powered design means you won’t need to worry about electrical wiring.

This detector also features event memory, which keeps track of CO concentrations of 100 ppm or greater—the level at which CO is considered high. The LED light system pulses red in unison with the alarm when CO is detected. When the air is clean again, the LED pulses green every 60 seconds to indicate that all is safe and working properly. It may not have the bells and whistles of other models, but it does the job effectively, has high user ratings, and is backed by a 10-year limited warranty.

Price at time of publication: $18

Product Details:

Sensor Type: Carbon monoxide
Power Source: Battery
Digital Display: No
Interconnectivity: No
Features: Low battery hush, event memory, low battery signal, test/reset button, LED light system

Klein Tools ET110 Carbon Monoxide Tester and Detector

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Why We Like It: The instant readings and portability make this CO detector a must-have for a job site.

It’s Worth Noting: This model doesn't continuously monitor, so you'll need to check it frequently.

The handheld ET110 Carbon Monoxide Tester and Detector from Klein Tools is ideal for transporting readings from room to room. This portable device not only detects carbon monoxide but also displays the temperature of each area. It has a bright, easy-to-read LCD display and features an audible and visual alarm for dangerous CO concentrations—a low-level alarm at 35 ppm and a high level at 200 ppm. The warning indicator light blinks green for clean air and red when CO is detected.

Perfect for home inspectors, contractors, and those who need an on-the-go CO detector, the ET110 is powered by four AAA batteries. An included carrying pouch makes it easy to transport and store. Other noteworthy features include an auto power-off setting to help conserve battery life after 20 minutes and instantaneous readings from 0 ppm to 1000 ppm. This model is best for spot-testing CO levels and is not designed for continuous monitoring.

Price at time of publication: $96

Product Details:

Sensor Type: Carbon monoxide
Power Source: Battery
Digital Display: Yes
Interconnectivity: No
Features: Low- and high-level alarms, backlit display, temperature, auto shut-off, audible and visual alarm, included carrying pouch

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

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Why We Like It: This plug-in model has a battery backup for peace of mind.

It’s Worth Noting: The device doesn't display readings below 30 ppm.

Plug-in carbon monoxide detectors are a great way to ensure that your home is safe from the dangers of CO—without the worry of replacing batteries. The Nighthawk Carbon Monoxide Detector from Kidde is an excellent choice with a simple, reliable operation. The backup 9V battery keeps the alarm going during power outages for added peace of mind.

This detector features a digital display that shows CO concentration levels measured in parts per million and provides an event memory history for reviewing levels. A peak-level button allows you to check the highest CO concentration levels since your last reset. When CO is detected, the alarm sounds and displays the current level, which updates every 15 seconds. An LED light on the cover also pulses red during an alarm. The low-profile design and included 6-foot extension cord top off this effective detector.

Price at time of publication: $28

Product Details:

Sensor Type: Carbon monoxide
Power Source: Plug-in with battery backup
Digital Display: Yes
Interconnectivity: No
Features: Digital display, peak-level button, event memory history, test/reset button, 6-foot extension cord, 9v battery back-up

X-Sense CD07 Carbon Monoxide Detector Alarm

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Why We Like It: Real-time CO levels update every 10 seconds.

It’s Worth Noting: This device is designed for wall mounting only.

The X-Sense CD07 is a powerful, battery-powered carbon monoxide detector that packs all the features of a plug-in model into a small and lightweight device. It’s powered by an included CR123A battery that provides up to 10 years of continuous use and has an easy-to-read LCD display for displaying CO concentrations in ppm. Battery level and working status are also clearly displayed.

This detector boasts a self-check function that tests its internal operating circuits and sensors and alerts you when it needs replacement or servicing. A button allows you to test the detector's audio and visual alarms as well as silence them. We love this detector's added safety features, such as peak-level memory and 10-second updates of CO levels. It’s also backed by a five-year warranty in case it ever fails.

Price at time of publication: $28

Product Details:

Sensor Type: Carbon monoxide
Power Source: Battery
Digital Display: Yes
Interconnectivity: No
Features: Self-check function, test/silence button, peak-level memory, LCD display, 10-second updates of CO levels, five-year warranty.

Kidde KN-COPE-IC Hardwire Carbon Monoxide Alarm with Digital Display

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Why We Like It: This model links with up to 24 other Kidde devices, including CO monitors, strobe lights, smoke alarms, and heat alarms.

It’s Worth Noting: The device requires hardwiring to your home's electrical system.

This hardwired KN-COPE-IC model is a reliable carbon monoxide detector. Hardwired devices are great for providing continuous protection and are especially useful for large properties. Their ability to interconnect other sensors means that a single alarm will sound throughout the entire area in an emergency, safeguarding your large family or business. This model also doubles as a smoke alarm for added protection.

This model packs several smart features into its traditional detector body, including a digital display and voice alert system that clearly announces the danger and level of carbon monoxide. A peak-level memory feature allows you to check the highest CO level since it was last reset. Although it has a 10-year battery backup, the device itself has a seven-year operating life.

Price at time of publication: $43

Product Details:

Sensor Type: Carbon monoxide, smoke
Power Source: Hardwired with battery backup
Digital Display: Yes
Interconnectivity: Yes, up to 24 Kidde devices
Features: Digital display, voice alert system, peak-level memory feature, 10-year battery backup, seven-year operating life

FIRST ALERT Hardwired Smoke Detector and Carbon Monoxide (CO) Detector

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Why We Like It: The side load battery compartment with a lock is easily accessible for changing batteries.

It’s Worth Noting: This device is hardwired and requires installation.

Smoke and carbon monoxide detectors are must-haves for any home, and this hardwired device from First Alert makes it easy to have both. This detector is perfect for those who don't want the hassle of battery replacements—it features an AC wiring connection that eliminates the need to replace batteries. With the bonus of a battery backup, you'll always be prepared during power outages.

This model detects both smoke and carbon monoxide by immediately sounding an alarm when a threat is present. The design allows you to wire up to 18 other compatible detectors in your home, so all linked alarms will sound in an emergency. It also has a test/silence button for silencing false alarms and a low-battery warning to indicate when it's time to replace the backup.

Price at time of publication: $35

Product Details:

Sensor Type: Smoke, carbon monoxide
Power Source: Hardwired with battery backup
Digital Display: No
Interconnectivity: Yes, up to 18 other compatible detectors
Features: Test/silence button, low-battery warning, interconnectable design, battery backup, 10-year limited warranty

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Why We Like It: The Nest Protect syncs into your existing Google home system for added convenience and protection.

It’s Worth Noting: The advanced features come at up to five times the cost of the other products on our list.

Google Nest's home protection products are top of the line, and this Nest Protect smoke and carbon monoxide detector is no exception. It houses both types of sensors in one device, with a separate alarm for each kind of emergency it detects. This advanced model can tell you the location of danger within your home and the level of CO present from its app-enabled display.

The Nest Protect features phone alerts for timely notifications when it detects an issue and voice alerts that tell you if danger is present. It can also convey its readings to the Google Home app for easy monitoring and control. Its split-spectrum sensor recognizes both fast and slow-burning flames to protect against active and potential fires. We love the built-in Pathlight that activates when motion is detected to light your way in the dark, but our favorite feature is the Nightly Promise, which displays a green glow each night to let you know it’s working.

Price at time of publication: $120

Product Details:

Sensor Type: Carbon monoxide, smoke
Power Source: Hardwired with battery backup
Digital Display: Yes
Interconnectivity: Yes, with the Google Home app
Features: Phone and voice alerts, Pathlight, split-spectrum sensor, app-enabled display

Kidde Plug-In Carbon Monoxide Detector with Digital Display

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Why We Like It: The LED display light adjusts its brightness to the light level in your home, so you can easily read it without straining your eyes.

It’s Worth Noting: This one’s on the pricier side for a plug-in model.

This Kidde Plug-In Carbon Monoxide Detector is a terrific choice if you want to see your CO levels at a glance. This model has an easy-to-read LCD digital display that will tell you the carbon monoxide concentration in your home with an automatic nighttime dimmer. It features a double bottom operation—one to test/hush the alarm, and the other to check peak CO levels and adjust the lighting.

The rotating plug adapts to vertical and horizontal outlets for added convenience. It has a sealed lithium battery for protection during power outages and an escape light that helps you find your way if an alarm sounds. Plus, it has a low-battery warning when it’s time to replace the backup. We appreciate the end-of-life chirp (around 10 years) that alerts you to replace the detector. A 10-year limited warranty fully backs this UL-Certified option.

Price at time of publication: $58

Product Details:

Sensor Type: Carbon monoxide
Power Source: Plug-in with battery backup
Digital Display: Yes, LCD digital display
Interconnectivity: No
Features: Rotating plug, escape light, low-battery warning, LED night light, sealed lithium battery backup, peak level memory, 10-year limited warranty

X-Sense Carbon Monoxide Detector Alarm with Digital LCD Display

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Why We Like It: This detector is smaller than most smartphones.

It’s Worth Noting: The operating temperature is 40 degrees to 100 degrees, so it may not work in some climates.

The X-Sense Carbon Monoxide Detector Alarm is travel-friendly with its duo wall-mounted or free-standing design. This detector boasts a digital LCD display and an alarm system that beeps when it detects dangerous levels of CO. The included five-year battery is reliable and long-lasting—a chirp and yellow light alert you of a low battery. It also features a single test/silence button for easy testing and silencing of alarms.

We appreciate the compact design and built-in stand, which allows you to place it on small surfaces like shelves, nightstands, and countertops. Installation is quick and painless, thanks to the included mounting screws. While X-Sense sells a similar interconnected model, this product does not feature any interconnectivity options. However, its advanced CO sensor and loud alarm make it a reliable, compact choice.

Price at time of publication: $27

Product Details:

Sensor Type: Carbon monoxide
Power Source: Battery
Digital Display: Yes
Interconnectivity: No
Features: Alarm system, single test/silence button, digital LCD display, mounting screws included

How We Selected the Best Carbon Monoxide Detectors

To determine the best carbon monoxide detectors, we spoke to safety experts about the top features to look for and the highest-rated products on the market. We looked at factors including sensor type, power source, display options, interconnectivity with smart home systems, and other features that make a detector stand out from the rest. We also considered user ratings in our selection process to ensure that we only featured top-tier sensors with proven results.

Our ultimate goal was to provide a comprehensive list of quality detectors that meet UL safety standards—ensuring you get the best protection from CO exposure. With the help of our experts, we researched hundreds of carbon monoxide detectors and selected the most reliable options currently on the market.

What to Know About Carbon Monoxide Detectors

What is Carbon Monoxide?

Carbon monoxide (CO) is an odorless and colorless gas that can be especially dangerous in homes and other indoor spaces. It's produced whenever something burns, including gas stoves, fireplaces, car engines, and furnaces.

"Carbon monoxide is a byproduct of incomplete combustion," explains Dave Miller, firefighter, hazardous materials technician, paramedic, and owner of Frontline Medical Defense. "When anything burns, one of its byproducts is carbon monoxide."

High levels of CO can build up quickly in an enclosed space, leading to carbon monoxide poisoning. Symptoms of CO poisoning include dizziness, nausea, headaches, and fatigue. It can even be fatal. Because the gas is odorless and colorless, the only way to detect it is with a carbon monoxide detector.

Why You Need a Carbon Monoxide Detector

The only way to know if your home or business is at risk of CO poisoning is to install a carbon monoxide detector. CO detectors alert you of the presence of carbon monoxide and sound an alarm when it reaches a certain threshold. They come in various shapes and sizes, so you can easily find one that fits your needs.

While every home should have a CO detector, it's especially important in areas with fuel-burning appliances or combustion sources. It's also wise to install one near sleeping areas, as CO poisoning can be especially dangerous while you sleep.

"Carbon monoxide is truly the silent killer," warns Miller. "Carbon monoxide kills hundreds of people yearly, typically in their sleep." Arming your home with a quality CO detector is the best way to protect your family and guests from carbon monoxide poisoning.

Miller adds, "You should place a detector on every level of your home." That will ensure you get the most comprehensive coverage and are alerted to any changes in CO levels.

Types of Carbon Monoxide Detectors

According to Miller, there are three main types of carbon monoxide detectors:

Electrochemical sensor: This type of detector uses an electrochemical sensor that is more sensitive to carbon monoxide. It's the most accurate and reliable CO detection method and often displays real-time CO levels on the unit. They typically last for five to seven years.
Metal oxide: This type of detector uses a metal oxide semiconductor to detect carbon monoxide. They're generally plug-in models and require electricity.
Biomimetic: This type of detector uses gel-covered discs to detect carbon monoxide. The gel changes color when it comes in contact with CO and triggers the alarm system.

Power Source

When it comes to powering your carbon monoxide detector, there are several options:

Hardwired: This type of detector is wired into the home's electrical system and runs on AC power. They usually come with a battery backup in case of a power failure.
Battery-powered: These detectors typically run on standard AAA or 9V batteries and are great for areas without an electrical outlet.
Plug-in: These detectors plug into a wall outlet and use electricity to power the unit. Some are equipped with battery backups in case of a power failure.

Depending on your needs, you may choose a combination of these power sources. Those who travel may prefer a battery-powered detector to take with them. However, hardwired models boast a few noteworthy features.

"The benefit of a hardwired detector with a battery backup is that if your house loses power, the battery will run the detector for you," explains Miller. "And likewise, if the battery dies, the power from the house will power the detector."

Accuracy and Sensitivity

Before purchasing a carbon monoxide detector, it's important to understand its accuracy and sensitivity. CO detectors can "drift" over time, making them less sensitive as they age. To ensure that your detector works properly, it's best to check it at least twice a year.

Be sure to choose a detector approved by a recognized safety organization such as UL, which is a leader in safety product testing and certification. UL-approved products are tested to the highest possible standards to ensure they deliver accurate results.

Interconnectivity

Interconnectivity refers to the ability of multiple detectors to communicate with each other. For example, if one detector detects a dangerous level of CO in your home, all the other linked units will be alerted. This is especially helpful for larger homes and those with multiple levels, as it ensures everyone is notified in an emergency.

When shopping for a carbon monoxide detector, look for one that is compatible with your existing system. Many newer models have interconnectivity built-in, but if yours doesn't, you can purchase an adapter or a separate device to enable it. Some models lack this feature altogether, so be sure you understand what you're buying before you make your purchase.

Features

Every model of carbon monoxide detector is unique and has its own features. Some of the most popular features include:

Alarms: Many detectors come with audible alarms and visual indicators to alert you when CO is detected. Some models also provide a digital readout of the CO level for added safety.
Voice alerts: This feature allows the detector to audibly inform you when CO levels reach dangerous thresholds, allowing you to take action in an emergency.
End-of-life warning: Many detectors come with an end-of-life warning system, which activates when the device has reached the end of its useful life. This gives you ample time to replace it before it fails to protect your family.
Battery backup: Detectors powered by your home's electricity will usually have battery backups in case of a power failure.
Smart technology: Some of the latest models come with Wi-Fi capabilities and compatibility with home automation systems, allowing you to monitor your CO levels from anywhere using an app on your smartphone or another connected device.

Your Questions, Answered

How often should you replace a carbon monoxide detector?

"It's important to regularly check your carbon monoxide detectors for maintenance and ensure they're working properly," says John Smith, a fire safety expert and company director of Fire Risk Assessment Network. "The National Fire Protection Association recommends replacing them every five years as part of a regular home safety inspection routine."

According to Smith, though, if your detector is expired or faulty, you should replace it immediately. And if you live in an older home that has never had a CO detector installed, now is the time to get one.

Where is the best place to put a carbon monoxide detector?

Placement of your carbon monoxide detector is key to ensuring that it works properly. Smith recommends installing one:

On each level of your home
In sleeping areas
Near fuel-burning appliances, such as your furnace or water heater

Follow the manufacturer's instructions when placing a CO detector near fuel-burning appliances. Smith recommends placing the device "at least 10 feet away" from your appliance for optimal performance and accurate readings.

How many carbon monoxide detectors do you need in your home?

You don't need a detector in every room of your house, but you should have at least one on each floor, including the basement. If you have fuel-burning appliances such as a furnace or water heater, Smith recommends placing one nearby, as long as it's at least ten feet away.

If your home has multiple levels, consider installing interconnected detectors that alert all the detectors in your home when one is triggered to ensure that everyone in your home will be notified if there is an emergency in the house.

How much does a carbon monoxide detector cost?

The cost varies, depending on the features and quality. Basic detectors start at around $20, while more advanced models with additional features can range up to $150 or more. When making your purchase, consider your budget, the size of your home, and what features you need.

Many homes need multiple detectors, so keep the quantity in mind when budgeting for your purchase. Factor in the installation cost if you choose a model that requires professional installation. Most can be installed fairly easily, but you may need to hire an electrician if your detector requires hardwiring, and you're uncomfortable doing it yourself.

No matter the cost, your family's safety is worth investing in a quality carbon monoxide detector. It should last you several years and provide peace of mind that your home is protected.

Who We Are

As a nurse and public health professional, Lindsay Modglin is an experienced journalist who covers the rapidly evolving health and medical field. Her byline has been featured in global publications like Forbes, Insider, Verywell, and more. She enjoys researching and writing about the latest developments in health, wellness, and medical technology. Her goal is to help readers make actionable and informed decisions about the products and services they use to improve their lives.