Top 10 Best carbon dioxide monitor in 2026

Last Updated - 6/6/2026

🏆Best Choice

Kidde

Kidde Carbon Monoxide Detector, Battery Powered CO Alarm with LEDs, Test-Reset Button, Low Battery Indicator, Portable

9.8

ChoiceComparer.com Score

9.8

/ 10

Outstanding

Main highlights

•Electrochemical sensor technology detects CO gas
•Easy installation, no wiring needed, detects during a power failure by operating on 2-AA batteries (included); Install on a wall of your home or place on a tabletop
•Green LED indicates power to the carbon monoxide detector, while an 85-decibel alarm & a red LED indicates the presence of carbon monoxide
•Event Memory records the last time carbon monoxide was detected or when the unit was last tested

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$23.47

$27.57

-15%

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First Alert

First Alert Carbon Monoxide Detector, Plug-In Alarm with Battery Backup, CO605, White, 1-Pack

9.7

ChoiceComparer.com Score

9.7

/ 10

Outstanding

Main highlights

•Keep your family safe with this easy to use plug in carbon monoxide alarm; It works with any standard outlet and also has a battery backup for continuous monitoring of Carbon Monoxide levels, even if there's a power failure
•Features an advanced electrochemical carbon monoxide sensor that accurately detects carbon monoxide levels, no matter where the detector is placed in the room
•Simple to use, with a single test/silence button; a loud 85 decibel alarm sounds when Carbon Monoxide levels reach dangerous levels. Low battery signal mute, quiets low battery signal for upto 8 hours
•To ensure complete protection make sure to place one on each level of your home and in each bedroom
•7 year limited warranty; Equipped with end of life signal chirp, so you know when it’s time to replace the unit for safety
•All first alert CO alarms are rigorously tested to meet UL standards. Item length is 3.4 inches , item width is 1.38 inches and item height is 5 inches
•Loud 85-decibel alarm sounds when CO levels are elevated

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$27.99

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First Alert

First Alert CO400 Carbon Monoxide (CO) Detector, Battery Operated Alarm, 1-Pack

9.5

ChoiceComparer.com Score

9.5

/ 10

Outstanding

Main highlights

•Keep your family safe with this easy to use, battery operated carbon monoxide alarm; Battery powered alarms provide continuous monitoring of CO levels, even if there's a power failure
•Features an advanced electrochemical carbon monoxide sensor that accurately detects carbon monoxide levels, no matter where the detector is placed in the room.The alarm sequence should last 5-6 seconds. If it does not alarm, make sure fresh batteries are correctly installed, and test it again. If the unit still does not alarm, replace it immediately
•A loud 85 decibel alarm sounds when CO levels reach dangerous , Battery Replaceable - Yes
•To ensure complete protection make sure to place one on each level of your home and in each bedroom
•5-year limited warranty; Equipped with end of life signal chirp, so you know when it’s time to replace the unit for safety
•All first alert CO alarms are rigorously tested to meet UL standards
•First Alert has been the most trusted brand in home safety since launching the first residential smoke alarm in 1958 (Based on a First Alert Brand Trust Survey in February 2018)

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$19.99

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Dienmern

CO2 Carbon Dioxide Detector, Dienmern Portable Air Quality Monitor Indoor, 1600mAh Powerful Battery CO2 Monitor for CO2, Temp(°F), Humidity, LED Display CO2 Detector for Travel/Office/Home/Grow Tents

9.4

ChoiceComparer.com Score

9.4

/ 10

Excellent

Main highlights

•【CO2 monitor】 This CO2 monitor keeps track of CO2, AQI, temperature, and humidity in real time. It’s made to give you clear, easy-to-read info at a glance, so you can stay on top of your indoor air quality and keep your space healthier and more comfortable.
•【Swiss-Made High-Precision CO2 Sensor】 Built with a Swiss-made CO2 Sensor, this air quality tester gives you highly accurate CO2 readings every second. With a wide detection range of 400–5000 ppm and accuracy of ±50 ppm, it keeps you informed of changes in your air. Plus, the added temperature and humidity sensors provide complete indoor monitoring for a healthier environment.
•【Life-Saving CO2 Alarm】 This smart CO2 detector helps protect you from hidden dangers like gas leaks, wildfire smoke, or poor ventilation. The moment CO2 levels climb above safe limits, it sounds a loud alarm right away—so you have time to react and keep your loved ones safe
•【Built-in 1600mAh Battery】 With a built-in 1600mAh lithium battery, this air quality monitor can run for up to 72 hours on a single charge. It supports USB charging and is lightweight enough to carry around, while also perfect for keeping in one spot at home or the office.
•【Smart Visual Display】 This indoor air quality monitor comes with a bright LED screen that shows CO2, AQI, temperature, and humidity in real time. The clear visuals and high contrast make it easy to read at a glance, anytime—day or night—so you always know what the air around you is like.
•【Necessity of Air Quality Monitoring】Low levels of carbon dioxide detector are generally harmless, but when the concentration exceeds a certain limit, it can affect breathing in humans and other living organisms. In severe cases, it can even become life-threatening. Therefore, monitoring CO2 levels in the air is essential for maintaining a healthy environment.
•【Note】Dear customer, just a heads-up: CO2 meters can have a little variation of around ±50 ppm. That’s simply because each CO2 meter uses a different sensor, so the readings might not be exactly the same. Thanks for your patience and understanding.

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$18.99

$25.99

-27%

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Temtop

Temtop CO2 Monitor Indoor air Quality Monitor Portable CO2 Meter, CO2, Temperature, Humidity Home, Office or School

9.2

ChoiceComparer.com Score

9.2

/ 10

Excellent

Main highlights

•【Multifunctional CO2 monitor】Real-time CO2 detect, humidity and temperature monitor. CO2 detection range: 400-5000PPM. Temperature detection range: -10-60°C (14-140°F). Humidity detection range: 0-99%RH.
•【Cost-effectiveness and 70 days standby】the latest Photoacoustic CO2-Sensor incorporates intelligent algorithm , offering dual detection modes and using up to 70 days ! It provides you with the most cost-effective CO2 detector.
•【Mini and Multi Application】Small and thin , easy to carry, also with a detachable stand and adsorptive back cover. You can check air quality anywhere and anytime.
•【Multiple alarm modes 】the color coding and optional alarm, will sound the warning when the CO2 concentration exceeds the limit.
•【No Disturb for a Worry-Free Life】the sound alarm can be turned off, and without backlight, no noise and light disturbances, allowing you to easily fall asleep at night.
•【What's Included】 Detector x 1, USB cable x 1, User manual x 1, Bracket or accessories set x 1.
•【Tip】 For real-time monitoring, we recommend keeping the device plugged in. This will enable real-time monitoring mode, providing you with the most accurate and timely air quality data. Please note that this is a CO2 monitor and cannot detect carbon monoxide (CO).

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$45.99

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YISPK

Air Quality Monitor, Professional Air Quality Detector with CO2 Monitor/HCHO/TVOC/Temperature/Humidity for Home, Hotel, Office, Car

9.1

ChoiceComparer.com Score

9.1

/ 10

Excellent

Main highlights

•5 in 1 indoor air quality monitor, it tracks carbon dioxide (CO2), formaldehyde (HCHO), volatile organic compounds (TVOC), temperature and humidity, helping you stay aware of air quality and potential health risks.
•Ideal for various settings including homes, offices, schools, and hotels, this monitor helps maintain a healthy environment by continuously tracking airborne pollutants and climate conditions.
•Simple to set up and operate, making it accessible for anyone concerned about indoor air quality without the need for professional installation.
•Up to 20 hours of continuous use, you don't need to keep it plugged in. This indoor air quality meter is small and portable, can detect the gas quality in bedroom, living room, kitchen, office, car, school, hotel, cellars, restaurant, campground and other environments.
•By integrating advanced laser particle sensors with temperature and humidity sensors, making high-precision air quality monitoring more accessible than ever.

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$23.99

$29.99

-20%

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U UNNI

U UNNI CO2 Monitor Carbon Dioxide Detector for Home, 3 Adjustable Volume for Alerts & 3 Adjustable Backlight, Photoacoustic Sensor for Temperature Humidity & Indoor Air Quality Monitor

8.9

ChoiceComparer.com Score

8.9

/ 10

Great

Main highlights

•CARBON DIOXIDE DETECTOR for HOME, SWITCH °C/°F – Great item for any home to monitor the weather and air quality! Real-time CO2 value, temperature and humidity, CO2 history chart, CO2 Concentration range, 3 Adjustable Volume for Alarm Setting & 3 Adjustable Backlight, Max/Min Data, Low battery indicator.
•HIGH-PRECISION SENSIRION CO2 SENSOR – Equipped with Swiss-made Photoacoustic Sensor provides precise and reliable readings, which gives you peace of mind about the air in your home. CO2 detection range：400～5000PPM,accuracy：+/- 5% + 50PPM. Temperature range: 14.2°F ~ 122°F, Humidity range: 20% to 95 %.
•IMPROVE VENTILATION – Very useful for high concentration of poor air quality and cooking indoors and it will indicate to open a window/door to refresh the area to get the levels lower. CO2 monitor for Home, RV, Grow Tents.
•INDOOR AIR QUALITY MONITOR - Detect rise and decrease in carbon dioxide level, perfect for anyone wanting to monitor air quality! Elevated CO2 can cause symptoms like headaches, drowsiness, allergies and difficulty concentrating, to keep an eye on air quality at home or work!
•USB POWERED OPTION & BATTERY BACKUP & ADJUSTABLE BACKLIGHT – It is plugged in which allow the multi brightness display to stay on all the time, if you prefer. Either set it on tabletops, or mount it on the wall. 3 x AAA Battery(not included) for Backup & outdoor manual calibration.
•calibration process:Place the device in a standard calibration environment of 400PPM,Press and hold the ALERT button, and power on the device or install the battery,The device will sound "Bi-BI" and the screen will display the "CAL" character and keep blinking,After three minutes of calibration, the "PASS" character will be displayed. Power off and power on the device.

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$39.99

$59.99

-33%

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Lunarlipes

Lunarlipes Carbon Monoxide Detectors, Portable Carbon Monoxide and Carbon Dioxide Detector for Travel, Mini 4-in-1 CO and CO2 Monitor with Magnetic Suction, RV CO CO2 Detector Alarm Temp/Hum Sensor

8.8

ChoiceComparer.com Score

8.8

/ 10

Great

Main highlights

•【PORTABLE 4-IN-1 CO ＆ CO2 DETECTOR】The portable 4-in-1 carbon monoxide detector can monitor the current CO, CO2, temperature and humidity in the air in real time. Equipped with a high-precision sensor (10-year life), the detectable CO concentration range is 0~1000PPM (±10%), the CO2 concentration range is 400~5000PPM [± (50PPM + 5%)], and the temperature range is 14~122℉ (±2.7℉) / -10~50℃ (±1.5℃), humidity range is 0~95%RH (±5%RH). The data is accurate without delay and monitored in real time.
•【CO LIGHT INDICATION & CUSTOMIZED ALARM VALUE】The carbon monoxide monitor can present 3-stage light indication based on CO concentration. 0~49PPM (green flashing=safe), 50~99PPM (yellow flashing=warning), 100~1000PPM (red flashing=danger). By default, the CO monitor will sound an alarm when it reaches 50PPM. You can double-click the "function button" to customize the CO concentration alarm threshold. Note: The device must be in the "CO" interface before entering CO custom settings.
•【CO2 LIGHT INDICATION & CUSTOMIZED ALARM VALUE】The carbon dioxide monitor can present a 3-stage light indication according to the CO2 concentration. 400~699PPM (green flashing=safe), 700~1499PPM (yellow flashing=warning), 1500~5000PPM (red flashing=danger). By default, the audio alarm sounds when it reaches 1500PPM. You can double-click the "Function Button" to customize the CO2 concentration alarm threshold. Note: The device must be in the "CO₂" interface before entering the CO2 custom setting.
•【LARGE CAPACITY BATTERY & FAST CHARGING】The MINI 4-in-1 CO detector has a built-in 1000mAh lithium battery for long-lasting power. Support QC2.0, PD3.0, AFC, USB C UFP (BC1.2 DCP CDP SDP) and other common fast charging protocols 10~65W charging. When the CO detector is not operated for 5 minutes, it will automatically turn on the energy saving mode (the brightness of the screen will be reduced), and you can click the "function button" to turn on the backlight.
•【OUTDOOR LANYARD & MAGNETIC SUCTION】The bottom of the CO CO2 air quality monitor can be placed freely, you can put it on the table in the living room, kitchen, bedroom, etc. And it is equipped with a special outdoor lanyard, which is convenient for you to carry and use in outdoor activities such as travel, camping, picnic, and adventure. There is also a magnetic function on the back of the CO CO2 monitor, which can be attached to any metal area such as home appliances or cars.
•【SHOP WITH CONFIDENCE】Your satisfaction is our top priority. We provide 3 years service and lifetime technical support for our portable CO CO2 detector. If you encounter any problems, just contact us through Amazon Customer Service or Q&A and we will reply within 12 hours. Risk-free shopping. Customer satisfaction is our tireless pursuit.

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$49.99

$59.99

-17%

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Walfront

Air Quality Monitor Indoor CO2 Detector Carbon Dioxide Meter 5 in 1 HCHO TVOC Temperature Humidity Tester for Travel Home Grow Room

8.6

ChoiceComparer.com Score

8.6

/ 10

Good

Main highlights

•1 SECOND UPDATE: The air quality monitor can update the system 1 second in real time, and can directly detect air quality without calibration
•ACCURTAE DETECTION: The high performance analysis chip is used to accurately catch the weak current generated in the electrochemical process of CO2 Detector for more accurate detection
•BATTERY LIFE: The CO2 detector stands by time is about 240 to 360 minutes
•MULTIPLE USES: 5 in 1 meter can detect carbon dioxide concentration in air, and HCHO, TVOC, Temp, Humi
•SCRATCH ABS: Air quality meter adopt excellent ABS material, possess impact , scratch , environmentally friendly

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$20.27

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LSENLTY

LSENLTY Portable CO2 Detector, 2s Refresh High Accuracy Carbon Dioxide Monitor, 3 in 1 CO2 Meter(Temperature, Humidity and CO2 Value), 96 Hours Standby Time CO2 Monitor for Travel Camping Home Office

8.5

ChoiceComparer.com Score

8.5

/ 10

Good

Main highlights

•Portable Carbon Dioxide Detector: The product has a compact size (size: 7.6x7x3 cm) and is equipped with a strap design, suitable for hanging on the wall, car, or backpack. Suitable to use for camping, hanging on the wall in the living room or bedroom at home, or placed on the desktop in the office.
•3 in 1 Air Quality Monitor: LSENLTY 3 1 CO2 monitor not only has all the basic functions (CO2, temperature, and thermometer hygrometer monitor) but also smart functions such as remote monitoring, CO2 concentration, temperature, and humidity graph We support this. Our indoor CO2 detectors are reliable and easy to use in homes, greenhouses, etc.
•High Accuracy & Fast Refresh Time: With a high-quality smart sensor, CO2 accuracy is ±50PPM (CO2 detection range: 400-5000PPM) and temperature is up to ±1.8℉ (temperature detection range: 14-122℉). correct. Humidity is ±5%RH (humidity detection range: 0 to 95%RH). Always see the latest changes in CO2 concentration, temperature, and humidity with an update rate of up to 2 seconds.
•CO2 Alarm Function: When it exceeds 1500ppm, the alarm will sound automatically, and you can also set different alarm ranges according to your needs. You will receive an alert as soon as CO2 exceeds a preset range. Understand the condition of bedrooms, baby rooms, wine cellars, basements, plant nurseries, and other areas.
•CO2 Concentration Stage: This CO2 detector is designed with 3 stages of CO2 concentration: normal stage (400-700 ppm), warning stage (700-1500 ppm), and danger stage (1500-5000 ppm). LSENLTY CO2 detector provides you with a healthier life.
•Large capacity rechargeable battery: Built-in 1000mAh lithium battery, can be fully charged within 3 hours and can be used for about 96 hours. If there is no operation for 5 minutes, it will automatically go into energy-saving mode but don't worry, the carbon dioxide detection function will continue. Suitable for travel, car, home, office, etc.
•Notice: The product color ring step status display value is a fixed value, which is set by default according to international standards and cannot be changed.

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$34.99

$49.99

-30%

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