10 Best Carbon Monoxide Detectors 2026 in the United States

The First Alert CO400 carbon monoxide detector is a solid choice for anyone wanting dependable CO monitoring without the hassle of wiring. It uses an advanced electrochemical sensor, which is known for accurately detecting dangerous CO levels. Since it's battery operated using included AA batteries, you can place it anywhere in your home, even where power outlets are scarce, and it will keep working during power outages. The alarm is loud enough (85 decibels) to alert you clearly if CO levels become unsafe. This model comes with a practical end-of-life signal to remind you when it’s time to replace the device, helping maintain safety without guesswork.

It’s designed for easy installation—just place it on any level of your home or inside bedrooms, as recommended. The compact, white design is unobtrusive and fits most home styles. Users appreciate its reliability and the 5-year limited warranty adds confidence in its durability. One thing to note is that it does not have a digital display to show current CO levels, which some users might miss if they want detailed real-time info. Also, since it is battery powered, you will need to occasionally replace batteries to keep it functional.

For a simple, effective, and portable carbon monoxide detector, this model covers the essential features that most families need to enhance their home safety.

The First Alert Plug-In Carbon Monoxide Detector 3-pack is a good choice for keeping multiple rooms in your home protected from carbon monoxide. It uses an electrochemical sensor, which is a reliable and accurate method to detect CO levels. Since it plugs directly into any standard outlet, you don’t need to worry about replacing batteries, making it easy to maintain. The alarm is loud at 85 decibels, which should get your attention quickly in case of danger. It’s recommended to install one on every level of your home and inside each bedroom to maximize safety.

The detectors are well sized and simple to use, but because they rely on plugging into outlets, they may not be ideal for rooms without convenient power sources. Also, there’s no digital display to show current CO levels—alerts come only through sound—so you won’t get detailed information beyond an alarm sounding. The unit is tested to meet safety standards and comes with a 7-year limited warranty, adding peace of mind. If you want a straightforward, reliable detector that covers multiple rooms without fuss, this set is worth considering, especially if your home already has accessible outlets where you can plug them in.

The Kidde Carbon Monoxide Detector is a plug-in device with a 9-volt battery backup, ensuring reliability even during power outages. It uses an electrochemical sensor, which accurately detects carbon monoxide and certain explosive gases like propane and methane. The digital LED display shows the current CO levels or indicates when explosive gas is detected, providing real-time information beyond just an alarm. The alarm volume is 85 decibels, loud enough to alert you effectively. Installation is simple—you just plug it into a standard 120V outlet, suitable for most homes.

The unit includes a peak level memory function that records the last CO detection or test, which is useful for monitoring safety history. However, since it relies on plugging into an outlet, it might not be ideal for locations without nearby power sockets, such as some basements or garages. Also, the temperature operating range tops at 100°F, so very hot environments might affect performance. It weighs about a pound and is compact enough to fit discreetly on a wall.

This Kidde detector covers both carbon monoxide and certain gas alarms but does not detect natural gas specifically, so checking your fuel sources is important. Backed by a 5-year limited warranty and positive customer feedback, this device is a solid choice for typical home use, especially if you want combined gas and CO detection in one unit.