From smart home to simple units, we found the best CO detectors to keep your home and family safe.
6 min read
Reviewed ByRebecca EdwardsFor over 11 years, SafeWise experts have conducted independent research and testing to write unbiased, human reviews (not robots). Learn more.
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With 20+ years in tech journalism, Alina blends safety expertise with her passion for simplifying technology. Alina has tested hundreds of safety and security devices, is trained as a first responder, and has worked as a volunteer firefighter.
The best CO detectors marry safety features like smoke, fire, and carbon monoxide detection with intuitive smart features. We also like devices that integrate your home security system for extra protection if an alarm is triggered when you're not at home.
First Alert OneLink is our best overall carbon monoxide detector. It's a combo smoke and CO detector and comes with an option for voice alerts to minimize panic. Read on to compare this top carbon monoxide alarm to our other favorites.
What are the top carbon monoxide detectors?
- : Best overall
- : Best basic option
- : Easy installation
- : Best value
Compare CO detectors and alarms
Product | Best for | List price | Smoke sensor | Alarm decibels | Digital display | Learn more |
| Best overall | $79.99 |  Yes | 85 decibels |  No
| View on Google Store | |
| Best basic option | $46.99 | No
| 85 decibels | No
| View on Amazon | |
| Easy installation | $62.59 | No
| 85 decibels | Yes
| View on Amazon | |
| Best value | $27.94 | No
| 85 decibels | No
| View on Amazon |
*Amazon.com prices as of post date. Read full disclaimer.
Types of carbon monoxide detectors
There are several types of carbon monoxide detectors available for purchase. Some include multiple functions:
- Dual-function: sense different threats like CO, smoke, fire, and gas
- Digital: show you levels of carbon monoxide on a digital screen
- Smart: run diagnostics and sync with home automation apps
- Hardwired: wire into your home’s electrical grid, work unless the power goes out
- Battery-operated: basic sensing and display, need batteries to operate
Seasonal Storms and CO safety tips
Riding out a storm? Stay safe and prevent carbon monoxide sickness with these tips:
- Make sure CO and smoke detectors have fresh batteries (or battery backup)
- Never use a generator or a gas/propane heater in the house, garage, or a shed
- Don't use the stove or a grill to heat the house
- Don't run a vehicle for warmth and/or power, especially in an enclosed area
Carbon monoxide detector reviews
1. First Alert OneLink Best carbon monoxide detector
Best overall
First Alert OneLink is a combination smoke and carbon monoxide detector. My favorite feature is that instead of a loud beeping for the alarm, it has a voice to alert you.
Pros
Doubles as smoke detector
Comes with battery
Features voice notifications 
Cons
You'll need to replace the battery The alarm will also tell you what the problem is and where in your home it is coming from. This can give you the information you need to get out of the house safely without confronting the fire head-on.
The only downside is that you'll need to change the batteries from time to time. That's always a bummer.
2. First Alert CO605 Plug-In: Best basic option
Best basic option
The First Alert CO605 Plug-In carbon monoxide detector is just simple, and that's what I like about it. There's not screen, and just one button. Foolproof!
This affordable little gadget plugs into any regular outlet, so you don't need to worry about changing the battery. If you're like me and detest changing batteries, this is the carbon monoxide detector for you.
But if the power goes out, no problem. It has a battery backup.
Pros
Battery backup
One-button simplicity
85-decibel alarm
Silencing system
7-year warranty
Affordable Cons
No smart features
No smoke detection The First Alert CO605 Plug-In also comes with a seven-year warranty, 85-decibel alarm, and a silencing system for the battery alerts. Yep, you can mute the low-battery sound for up to eight hours.
3. Kidde Nighthawk Plug-in: Easy installation
Easy installation
When I say installing the Kidde Nighthawk carbon monoxide alarm is easy, I mean it. You won't need drills, screws, or even batteries. Like the First Alert CO605 Plug-In, just plug it in, and it’s all set. It also comes with a 9-volt backup battery in case of a power outage.
Pros
Affordable price
Digital display
Positive customer reviews
Backup battery Cons
Incompatible with home automation
Hardwired only Plug-in options like this gas and carbon monoxide detector keep renters and landlords happy. No need to drill holes in the wall.
Like other carbon monoxide detectors, it comes with a test button and LED screen to show the CO level in your home. When the Nighthawk detects dangerous levels in your home, it will play a signature beeping pattern so you won’t confuse it with any other alarms in your home.
The Kidde Nighthawk model that detects only CO isn't available as of our latest update. Still, we recommend the upgraded version, which also detects the buildup of explosive gases like propane and natural gas.
How do carbon monoxide detectors work for people with hearing loss?
Loud sirens are the standard for carbon monoxide detectors, but what if someone in your family has hearing loss? Try a specialized smoke and carbon monoxide detector for the hearing impaired, like the First Alert BRK 7030BSL, that triggers a strobe light when there's an emergency.
4. Kidde Battery-Operated: Best value
Best value
The Kidde Battery-Operated CO detector checks the air every 15 seconds for continuous monitoring with its electrochemical sensor. It doesn’t rely on hardwiring either, so it will continue to work even during a power outage. To top it off, it has a powerful 85 dB siren that sounds when it senses the poisonous gas.
Pros
No drilling required
Test button
Signature beep Cons
No home automation
No smoke detection
No battery backup While it lacks the smart features seen in the Nest and Onelink carbon monoxide detectors, it has all the marks of a reliable device. In addition to its loud siren and consistent monitoring, it has an LCD display. Plus, the green and red light to give visual safety cues to people with hearing loss.
If you need multiple CO detectors, this is a good device to start with. It’s affordable, dependable, and easy to install.
More brands we considered for best carbon monoxide alarm
Forensics Detectors FD
Forensics Detectors FD (about $100) makes a handy carbon monoxide alarm for car and truck use—it's a great tool for folks that drive for a living. This travel carbon monoxide detector is more sensitive than ones you'll find in most homes, making it easier to spot emissions issues in the cabin of your truck. Still, the sensor lasts only three years compared to the 10-year life of standard CO detectors.
Klein Tools
Klein Tools' (about $130) handheld carbon monoxide monitor is a diagnostic device an HVAC installer or mechanic would use. But while it's ultra-sensitive, it's not a safety device for the average homeowner.
Amazon Smart Air Quality Monitor
The Amazon Smart Air Quality Monitor (about $70) launched toward the end of 2021 and comes with a wealth of sensors to track indoor air quality: particulate matter, volatile organic compounds, carbon monoxide, humidity, and temperature.
But despite its ability to track CO levels, it's not actually a carbon monoxide alarm for emergencies. Amazon even goes as far as saying you still need a proper CO alarm when using this device. Still, it's got a lot of cool sensors and could be a good companion for an air purifier.
Carbon monoxide detectors FAQ
Check out our full carbon monoxide detector FAQ page to learn more about CO detection.
Carbon monoxide poisoning causes flu-like symptoms like dizziness, nausea, vomiting, headaches, confusion, weakness, blurred vision, sleepiness, or fainting.
If you're at home, get out of the house and call 911. CO poisoning doesn't always hit suddenly and doesn't leave your system quickly, so it's a good idea to seek medical attention as soon as you can.
According to the CDC, 400 Americans die from accidental carbon monoxide poisoning every year, and 100,000 are admitted to the emergency room.
Everyone is susceptible to carbon monoxide poisoning, but children, older adults, people who are physically ill, and pets are more likely to be affected by CO.
Carbon monoxide detectors work like smoke detectors but detect levels of carbon monoxide instead.
CO detectors usually have one or more of these sensors:
- Biomimetic detectors use color-changing gels that absorb carbon monoxide which triggers the alarm.
- Metal oxide semiconductors are carbon monoxide sensors that have silica chips that detect CO and send electrical signals to trigger an alarm.
- Electrochemical sensors use electrodes in chemical solutions that sense changes in electrical currents when carbon monoxide is present, and they sound the alarm.
Most professionally monitored security systems come with a CO detector. Check out our top security providers to see which home security systems include CO detectors with their monitoring plans.
Put a home carbon monoxide detector outside every separate sleeping area in your home, your kitchen, basement, and garage. We recommend finding an area far enough away from the carbon monoxide source but close enough to the areas you and your family normally occupy.
Check out our full guide on where to install your carbon monoxide detectors.
Yes, Google Nest Protect is being discontinued. Right now, the company is selling off what stock it has left and will offer new models from First Alert and Yale. Google Nest Protect was at the top of our list for CO detectors, but we removed it due to its discontinuation.
CO detector maintenance
Just like your smoke detectors, it's a good idea to test your CO detector monthly. Start by pressing the “test” button to ensure the siren works. If your detector is older, you can purchase a carbon monoxide meter to find out if your detector is still fully functional. If the carbon monoxide sensor doesn’t go off when you test it, it’s probably time to buy a new one.
Sources of carbon monoxide gas
Image: SafeWise.com
Carbon monoxide (CO) has been called the “silent and invisible killer” because it doesn’t have a smell, color, or taste. It’s one of the most prevalent causes of death due to poisoning in America. Any time you burn something—like gasoline, natural gas, wood, oil, propane, or charcoal—carbon monoxide is released into the air.
In outdoor spaces, this usually isn’t a health hazard because there is enough area for the CO to dissipate, so particles never amount to a toxic level. The danger comes when carbon monoxide is released in a contained area like your home, RV, or garage.
Anything that burns will create carbon monoxide. It’s not just your stove, fireplace, or grill either. Here are some of the things that can create carbon monoxide when turned on:
- Appliances
- Gas grills
- Gas stoves
- Gas or oil-burning furnaces
- Fuel-burning water heaters
- Pressure washers
- Generators
- Non-electric cars, trucks, and boats
- Chain saws
- Non-electric space heaters
- Tools
- Snowblowers
- Lawnmowers
Know what to do and what not to do
Lighting a fire in your fireplace is okay if it’s properly ventilated. However, keep the following in mind or you could cause a dangerous level of carbon monoxide to build in your home:
Do
Always vent gas appliances properly
Check your chimney annually to ensure proper ventilation Don't
Don't use charcoal or gas grills inside your home
Don't use a gas stove/oven for heating
Don't leave the car running with the garage door closed
Don't turn on your car with a blocked tailpipe (by snow or anything else)
Don't run a generator in your home or within 20 feet of your home’s doors, windows, and garage
Don't patch or seal vent pipes with tape or unapproved products—carbon monoxide could leak into your home 
With decades of safety experience, we compared smart features, installation ease, and detection accuracy to find the best carbon monoxide detectors. We also looked at user reviews to better understand how these devices work firsthand.
Visit our methodology page to learn more about how we conduct reviews like this one.
Final word: First Alert OneLink is the best
After hours of research and testing, we’ve found the best carbon monoxide detectors and smoke detector combos available. From basic battery-operated to smart carbon monoxide alarm devices, we think the First Alert OneLink is the best option for most folks. We like its voice features and the added safety of smoke detection to help keep you safe.
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Disclaimer
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product. Safewise.com utilizes paid Amazon links.
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