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The Best Carbon Monoxide Detectors

Carbon monoxide detectors sense dangerous levels of this odorless and colorless gas in your home. Whether you’re looking for a hardwired or battery-powered CO detector, we feature our top 12 picks for the best detectors, including their prices and what to look for when purchasing one for your home.
Updated Apr 28, 2021
Written By
Safety Team | Home Security Experts
Evaluated over 90 safety products to help you protect what matters most. Check our Methodology

How to Choose a Carbon Monoxide Detector: 3 Things to Consider

  • Power

    You can choose between a hardwired, battery or plug-in connection for your carbon monoxide detector. The best option depends on what’s most convenient and helpful for you. While a hardwired carbon monoxide detector provides consistent energy without battery replacement, one perk to battery-operated carbon monoxide detectors is power during an outage. However, some hardwired CO detectors feature backup batteries for use during an outage. If you’re looking for easy installation, plug-in versions are a great option.

  • Digital Display

    Purchasing a carbon monoxide detector with a digital display makes it easier for you to monitor your home’s CO levels. Dangerous levels of carbon monoxide register above 101 parts per million. A siren or voice will alert you if these dangerous levels are detected in your home.

  • Dual-Sensing

    There are several carbon monoxide detectors with dual-sensing capabilities. From smoke to gas, these detectors can help you identify more than one dangerous element in your home. Dual-sensing detectors typically feature specific alerts that indicate which problem needs to be addressed.

Types of Carbon Monoxide Sensors

There are four commonly used carbon monoxide detecting sensors used for sensing and alerting.
  • Biomimetic sensor:

    The biomimetic sensor uses a combination of color-changing liquids or gel-like elements to detect carbon monoxide. Detectors that use this sensor last up to three years.

  • Metal oxide semiconductor:

    This sensor is created using wired circuits to monitor carbon monoxide. Most detectors that use this sensor last up to 10 years.

  • Electrochemical sensor:

    The electrochemical sensor is considered best-in-class. Electrochemical carbon monoxide sensors generate currents that show the amount of carbon monoxide detected through a scientific combination. These devices operate best in most home temperatures and feature long lifespans.

  • Optochemical sensor:

    As the most cost-effective carbon monoxide sensor, this sensor uses a pad that changes colors when carbon monoxide is found. Although carbon monoxide detectors with this sensor may be affordable, they offer limited protection. Optochemical sensors can only detect whether carbon monoxide is present. Without knowing carbon monoxide levels, danger could be closer than known.

Compare Carbon Monoxide Detectors

Nest Protect Carbon Monoxide and Smoke Alarm (2nd Gen)

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X-Sense Combination Smoke & CO Detector

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Nighthawk Plug-in Carbon Monoxide Alarm

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First Alert CO710 Carbon Monoxide Detector

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First Alert CO400 Carbon Monoxide Detector

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Kidde Carbon Monoxide and Smoke Alarm

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Kidde Plug-In Carbon Monoxide & Gas Detector Alarm

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Ring Alarm CO and Smoke Listener

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ADT Carbon Monoxide Alarm

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Wewalab CO Detector

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SimpliSafe CO Detector

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Cove Carbon Monoxide Detector

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4.5 stars5 stars5 stars5 stars5 stars5 stars4.5 stars4.5 stars4 stars4 starsN/AN/A
BatteryBatteryPower cable and batteryBatteryBatteryBatteryBatteryBatteryWired or batteryBatteryBattery Battery
Digital Display
NoNoYesYesNoNoYesNoNoYesNo No
Voice Notifications
YesNoNoNoNoNoNoNoNoNoNo No
YesYesNoNoNoNoYesNoNoNoNo No

Compare Carbon Monoxide Detectors: Our 12 Picks

  • Top Certified Carbon Monoxide Detector

    1. Nest Protect Carbon Monoxide and Smoke Alarm (2nd Gen)

    Our rating

    Our take

    The Nest Protect smoke and carbon monoxide duo detector is designed to be easy to use. Easy-to-read light alerts and automatic mobile notifications make for a safe and smart home even when you’re away.

    Stand-out features include

    • Multi-colored light ring that shines red when detecting carbon monoxide
    • 10-year best-in-class electrochemical carbon monoxide sensor that uses electrodes to monitor electrical or fuel flows and detect carbon monoxide
    • Connects to the Nest Thermostat, which will automatically disable the furnace if carbon monoxide is detected to allow time for a safe evacuation
  • Best Smoke & Co Detector

    2. X-Sense Combination Smoke & CO Detector

    Our rating

    Our take

    This X-Sense smoke and CO detector features built-in photoelectric and electrochemical sensors for detecting smoldering fires and CO levels in your home. The battery is made to last for 10 years, and the alarm meets UL Standards.

    Stand-out features include

    • Detects both smoke and CO levels in your home
    • Battery is made to last for 10 years
    • Has a photoelectric sensor and an electrochemical sensor
  • Best Easy-to-Read CO Detector

    3. Nighthawk Plug-in Carbon Monoxide Alarm

    Our rating

    Our take

    This easy-to-install carbon monoxide alarm uses a digital display to indicate the home’s latest carbon monoxide levels. The Nighthawk can be plugged into any wall outlet and includes a backup battery for continued use during power outages.

    Stand-out features include

    • Digitally displays carbon monoxide levels
    • LED blinking light in the corner of the alarm to indicate that it’s working properly
    • 85-decibel alarm for a loud and clear sound if rising carbon monoxide levels are detected
  • 4. First Alert CO710 Carbon Monoxide Detector

    Our rating

    Our take

    This digital, easy-to-read carbon monoxide alarm uses an electrochemical sensor to quickly detect rising carbon monoxide levels. The alarm is equipped with a 10-year battery and chirping alarm to remind you when it’s time for a new detector.

    Stand-out features include

    • Loud and clear 85-decibel sound when alarming when CO is detected
    • Digital detector display of home temperature and carbon monoxide levels
    • 10-year built-in battery lasts the life span of the detector
  • 5. First Alert CO400 Carbon Monoxide Detector

    Our rating

    Our take

    The First Alert CO400 Carbon Monoxide Detector is designed with an electrochemical sensor for monitoring and detecting dangerous CO levels in your home. This device features a loud 85-decibel siren and has been tested to meet UL safety standards.

    Stand-out features include

    • 85dB (about as loud as a lawn mower)
    • Built-in electrochemical sensor for detecting CO levels
    • Tested to meet UL safety standards
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How to Install Carbon Monoxide Detectors

Carbon monoxide detectors should be installed in high-traffic areas. Start by adding detectors outside of bedrooms, the kitchen and common areas. At least one detector should be installed on each level of the home, including the attic and basement.

The best carbon monoxide detector placement is at knee level — often the height of a sleeper’s nose and mouth. If you have children and pets, place them at chest height or as high as needed to keep them out of reach.

When you travel, consider taking a small, TSA-approved CO detector with you for your rental property or hotel just in case one’s not installed. These can be plugged into power outlets and powered on with the touch of a button.

Benefits of Different CO Detector Features

There are several types of CO detectors. Below, we highlight the benefits of different types to help you choose the right one for your home. Before buying, don’t forget to check your state’s regulations.

  • Temperature-adjusting carbon monoxide detectors. Temperature-adjusting detectors limit false alarms that occur due to humidity or fluctuating temperatures.
  • Alarm clock carbon monoxide detectors. These alarms accurately detect carbon monoxide PPM. They offer different alarm sounds based on PPM and the estimated amount of time it takes to evacuate safely. 
  • Duo smoke and carbon monoxide detectors. This all-in-one detector features a smoke sensor and a carbon monoxide sensor that use the same power source. It features alerts tailored to the type of danger detected.
  • Smart CO detectors. Carbon monoxide alarms with smart technology allow you to monitor CO levels using a mobile app. They may also connect with your smart home system. 

Popular smart carbon monoxide alarms use control panels or mobile apps to manage programmable voice location settings. The alarm indicates the room where carbon monoxide is detected. Most of these detectors also connect to other smart home devices.

Carbon monoxide continues to be a silent threat in today’s homes. Understanding the ins and outs of carbon monoxide and preventative measures can protect your valuables and loved ones. With a firm grasp on the poisonous gas, you’ll be able to decide on the best carbon monoxide detector with ease.

Carbon Monoxide FAQs

Home Security Experts

Safety Team

The Safety Team is a group of experts that handle provider research, product reviews and recalls to make your home safety and security search as easy as 1-2-3.

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