10 Best Carbon Monoxide Detectors 2025 in the United States

The Kidde Carbon Monoxide Detector offers a straightforward, plug-in design with a handy 9-volt battery backup to keep it running during power outages. It uses an ionization sensor, which is effective at detecting carbon monoxide and is common in many detectors. The digital LED display is a useful feature, showing you the current CO levels in your home, which goes beyond basic alarms and adds peace of mind. The loud 85-decibel alarm ensures you will hear it clearly if dangerous carbon monoxide is detected.

Installation is very easy—just plug it into any standard 120V outlet, and it can also be placed on a tabletop if needed. The included battery backup and peak memory feature, which records the highest CO level detected or last test time, provide extra safety and convenience. This 2-pack is a great value for covering multiple rooms or floors. One minor drawback is that the sensor is ionization-based, which is generally good but some users prefer electrochemical sensors specifically designed for CO detection.

Also, the unit is designed for indoor use only and has an operating temperature limit of 100 degrees Fahrenheit, so it’s best suited for typical home environments. With a strong reputation, solid safety features, and easy installation, this detector is a good fit for homeowners who want reliable, user-friendly carbon monoxide protection without complexity.

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 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.