8 Best Plug-In Carbon Monoxide Detectors (October 2026)

The best plug-in carbon monoxide detectors include the Kidde Plug-In CO Alarm with Digital Display for display readers, the First Alert Plug-In CO Alarm with Digital Display for dim rooms, and the First Alert CO606 Plug-In CO Alarm for simple controls.

On this page (6 sections)

1. How we chose these plug-in carbon monoxide detectors
2. Best plug-in carbon monoxide detectors for different homes
3. How do you choose the right plug-in CO alarm?
4. How should you set up and care for a plug-in CO detector?
5. What mistakes should you avoid with a plug-in CO alarm?
6. Which plug-in carbon monoxide detector should you choose?

The best plug in carbon monoxide detector for most homes is the Kidde Plug-In CO Alarm with Digital Display, because it combines a CO-level readout, Peak Level Memory and 9V battery backup. Choose the First Alert CO606 for straightforward controls, or the Kidde COPDW if app alerts when you're away matter most.

A plug-in alarm is a practical choice when a suitable outlet is close to the room where you need coverage. Compare the backup battery, display and controls, outlet fit, and number of alarms your home needs before choosing.

Start room planning with our guide to how many carbon monoxide detectors you need. If you're deciding between outlet power and batteries, see plug-in vs battery carbon monoxide detectors.

Our picks at a glance

1. 1
   Best for display readers

   Kidde Plug-In CO Alarm with Digital Display

   9.0/10 our score

   See it on Amazon
2. 2
   Best for dim rooms

   First Alert Plug-In CO Alarm with Digital Display

   8.6/10 our score

   See it on Amazon
3. 3
   Best for simple controls

   First Alert CO606 Plug-In CO Alarm

   8.5/10 our score

   See it on Amazon

4. 4

   First Alert CO606 Plug-In CO Alarm 3-Pack

   Best for multiroom homes
   Check it
5. 5

   Kidde COPD Plug-In CO Alarm with Display

   Best for awkward outlets
   Check it
6. 6

   Kidde Plug-In CO Alarm with AA Backup

   Best for peak memory
   Check it
7. 7

   Kidde COP Plug-In CO Alarm

   Best for visual status
   Check it
8. 8

   Kidde Smart Plug-In CO Alarm, COPDW

   Best for remote alerts
   Check it

How we chose these plug-in carbon monoxide detectors

The best plug-in carbon monoxide detectors balance useful alerts, outage backup and a form that works with the outlets available. We compared display type, controls, backup batteries, connectivity and pack size against common household needs.

The scores reflect how each alarm's stated features fit the needs of someone shopping for a plug-in CO detector. The picks are ordered by score, with each one matched to a distinct use.

Best plug-in carbon monoxide detectors for different homes

The Kidde digital-display alarm is the strongest all-around fit for readers who want a visible CO reading and peak memory. The other picks suit buyers who prefer a backlit screen, simpler controls, multiple alarms, flexible plug direction, color status lights or phone notifications.

1

Kidde Plug-In CO Alarm with Digital Display: Best for display readers

9.0/10Our score

• 9V battery backup
• Digital display shows sensed CO level
• Peak Level Memory
• 85 dB alarm

A digital display and Peak Level Memory add context to a plug-in alarm. The included 9V battery provides backup during a power outage.

See it on Amazon

Pros

• Shows sensed CO level
• Records peak level memory
• Includes 9V backup battery

Cons

• Uses a 9V backup battery
• No phone alerts

The Kidde Plug-In CO Alarm with Digital Display suits anyone who wants a visible reading alongside the audible alarm. Its digital display shows the CO level being sensed, while Peak Level Memory records the last time CO was detected or the unit was tested.

A 9V battery provides backup during a power outage. The alarm plugs into a standard 120V outlet and sounds an 85 dB alarm when CO is detected.

This model includes an extension cord for table or shelf placement and mounting hardware for a wall-mount option. Those choices can help when the outlet itself is not in a convenient position.

Choose it if a readout and peak memory would help you understand the alarm's status. Skip it if you want phone notifications or prefer to keep the backup battery type consistent with other devices that use AA batteries.

2

First Alert Plug-In CO Alarm with Digital Display: Best for dim rooms

8.6/10Our score

• AA battery backup
• Backlit digital display
• Peak level feature
• 7-year limited warranty

The backlit screen shows CO and power levels, while the peak level feature displays the highest concentration measured. AA backup supports monitoring during a power failure.

See it on Amazon

Pros

• Backlit digital screen
• Displays peak level
• AA battery backup

Cons

• Backup batteries are not intended for extended use without AC power
• No phone alerts

The First Alert Plug-In CO Alarm with Digital Display fits rooms where a backlit readout is useful. Its screen shows CO and power levels, and its peak-level feature displays the highest concentration measured.

AA batteries provide backup during a power failure. First Alert says the backup is not intended to power the alarm for an extended period without AC, so the alarm should remain connected to a working outlet.

A test and silence button handles the basic controls. It also has an end-of-life signal chirp and a 7-year limited warranty.

Choose this model if you want a backlit display and AA backup. Skip it if you don't need a screen or want an alarm that can rely on battery power for an extended outage.

3

First Alert CO606 Plug-In CO Alarm: Best for simple controls

8.5/10Our score

• 9V battery backup
• Single test and silence button
• End-of-life signal chirp
• 7-year limited warranty

This CO606 keeps the controls simple with one button for testing and silencing. Its battery backup supports operation during power outages.

See it on Amazon

Pros

• Simple single-button operation
• Battery backup
• End-of-life signal

Cons

• No digital display
• No phone alerts

The First Alert CO606 is suited to buyers who want an alarm with a single test and silence button. It has no digital display, so there are fewer readouts to interpret.

Its electrochemical sensor sounds an 85 dB alarm when CO reaches dangerous levels. The low-battery signal can be muted for up to 8 hours, and an end-of-life chirp indicates when replacement is due.

Choose this alarm for basic controls and battery backup without a display. Skip it if seeing CO information on a screen or receiving phone alerts is important to you.

4

First Alert CO606 Plug-In CO Alarm 3-Pack: Best for multiroom homes

8.4/10Our score

• Three plug-in CO alarms
• Battery backup
• Single test and silence button
• End-of-life signal chirp

Three CO606 alarms can help cover more than one room or level. Each uses a standard outlet and has battery backup.

See it on Amazon

Pros

• Three alarms in one pack
• Battery backup
• Simple test and silence control

Cons

• No digital display
• No phone alerts

The First Alert CO606 three-pack makes sense when you need alarms for more than one room or level and want the same simple controls in each place. Each unit plugs into a standard outlet, includes battery backup and uses one button for testing or silencing.

All three alarms follow the CO606 design, with an 85 dB audible alert and end-of-life signal. Having several units in one pack can simplify choosing matching alarms for multiple locations.

Before buying, map the outlets near the areas where alarms are needed. A multi-pack helps with quantity, but it can't solve a shortage of suitable outlet locations.

Choose this pack when three locations need alarms and a basic audible model fits your needs. Skip it if you'd rather have a display in each room or your planned locations don't have useful outlets.

5

Kidde COPD Plug-In CO Alarm with Display: Best for awkward outlets

8.3/10Our score

• Backlit display
• Two AA backup batteries
• Rotating plug
• 10-year limited warranty

The rotating plug fits vertical or horizontal outlets, and the backlit display shows CO levels. Two AA batteries provide backup during outages.

See it on Amazon

Pros

• Rotating plug
• Backlit CO-level display
• Two AA backup batteries

Cons

• Requires a 120V outlet
• Not approved for RV or boat use

The Kidde COPD Plug-In CO Alarm with Display is designed for homes with vertical or horizontal outlets. Its rotating plug fits either orientation, and its backlit display shows CO levels.

Two AA batteries provide outage backup. The alarm has a Test/Hush button, an LED warning light and an 85 dB audible alert.

Kidde says this model is for conditioned spaces and isn't approved for RV or boat use. It requires a 120V outlet, so it may not work with 220V power.

Choose it if outlet orientation is awkward and you want a backlit display. Skip it for an RV, boat or a space without the specified power.

6

Kidde Plug-In CO Alarm with AA Backup: Best for peak memory

8.1/10Our score

• Two AA backup batteries
• 85 dB alarm
• Peak Level Memory
• Test-Hush button

Peak Level Memory records the last time CO was detected or the unit was tested. Two AA batteries provide backup power during an outage.

See it on Amazon

Pros

• Peak Level Memory
• Two AA backup batteries
• Test-Hush button

Cons

• No phone alerts
• No rotating plug feature stated

The Kidde Plug-In CO Alarm with AA Backup pairs Peak Level Memory with two AA backup batteries. It plugs into a standard 120V outlet and sounds an 85 dB alarm when CO is detected.

Its Test-Hush button supports function checks and temporary silencing. Peak Level Memory records the last time CO was detected or the alarm was tested.

Choose it if you want peak memory and AA backup without an app connection. Skip it if you need phone alerts or a rotating plug for a sideways outlet.

7

Kidde COP Plug-In CO Alarm: Best for visual status

8.0/10Our score

• LED status lights
• Two AA backup batteries
• Rotating plug
• 10-year limited warranty

The COP uses changing LED colors to show alert status and includes a Test/Hush button. Its rotating plug supports vertical or horizontal outlets.

See it on Amazon

Pros

• Color-changing LED status lights
• Rotating plug
• Two AA backup batteries

Cons

• No digital display
• Requires a 120V outlet

The Kidde COP is a fit for buyers who want a visible status cue without a digital display. Its LED lights change color based on alert status, and its Test/Hush button supports quick checks or temporary silencing.

Two AA batteries provide outage backup, and the rotating plug fits vertical or horizontal outlets. The alarm sounds at 85 dB when CO is detected.

Kidde says the alarm meets UL 2034 5th Edition standards and is ETL listed. It carries a 10-year limited warranty.

Choose the COP if color-changing lights and plug flexibility are useful. Skip it if you want a numerical CO reading or notifications on your phone.

8

Kidde Smart Plug-In CO Alarm, COPDW: Best for remote alerts

7.6/10Our score

• Kidde app notifications
• 2.4 GHz Wi-Fi
• Two AA backup batteries
• Alexa and Google Home integration

The COPDW sends CO notifications through the Kidde app and works with Alexa-enabled devices and Google Home. It requires a 2.4 GHz Wi-Fi connection.

See it on Amazon

Pros

• Phone notifications when home or away
• No subscription required for notifications
• Two AA backup batteries

Cons

• Requires 2.4 GHz Wi-Fi
• No hub stated as included

The Kidde Smart Plug-In CO Alarm, COPDW, is the best fit here for buyers who want app notifications when away from home. It sends real-time alerts through the Kidde app, with no subscription required for notifications.

It connects through 2.4 GHz Wi-Fi and works with Alexa-enabled devices and Google Home. Two AA batteries provide outage backup, and a rotating plug fits vertical or horizontal outlets.

Choose it if you can connect it to a 2.4 GHz network and want remote alerts. Skip it if you don't want a connected alarm or your Wi-Fi doesn't support the required band.

How do you choose the right plug-in CO alarm?

Start with the room and outlet, then decide what information and backup you want from the alarm. A model that fits your outlet and placement needs is more useful than a feature-rich alarm that can't be installed where coverage is needed.

Which backup battery suits your plug-in CO detector?

The alarms here use 9V or AA backup batteries. The Kidde digital-display model and First Alert CO606 use 9V backup, while the First Alert display model and several Kidde options use AA batteries.

Backup is meant to support the alarm during an outage, but that doesn't mean every model can run on battery for an extended period. Follow the specific manual for battery installation, replacement and outage guidance.

If you're still weighing outlet power against battery-only designs, our plug-in vs battery CO detector guide explains the main placement and power tradeoffs. Choose the battery type you can maintain, and keep replacement batteries available if the manual calls for them.

Is a display or a simple alarm a better fit?

A display gives you a visible CO readout or other information, while a simpler alarm keeps attention on audible alerts and basic controls. Models such as the Kidde KN-COPP-3 and First Alert CO615 show CO information, while the First Alert CO606 has no digital display.

Peak memory can help you see a recorded high point or the last event, depending on the model. It doesn't replace the alarm sound or tell you to ignore an active warning.

Choose a display if you value a visible status check. Choose a simpler alarm if a screen would go unread or you want fewer controls.

Will the plug fit your outlet and leave the alarm in a useful spot?

A plug-in alarm needs an appropriate outlet, and the position of that outlet affects whether the alarm is easy to hear and access. The rotating plugs on the Kidde COPD and COP are designed to fit vertical or horizontal outlets.

Before choosing, check that the outlet is powered and that the alarm won't be blocked by furniture or hidden behind an object. Use the alarm's instructions to confirm placement and keep the controls accessible.

An extension cord is included with the Kidde KN-COPP-3 for table or shelf placement, and that model also includes wall-mount hardware. Check the manual for how to use these options safely.

How many alarms should you plan to buy?

Count the locations that need coverage before selecting a single alarm or multi-pack. Several models recommend an alarm on each level of the home and in each bedroom, so follow the instructions for the specific model and local guidance.

The First Alert CO606 three-pack can cover several outlet locations with matching alarms. It won't help if the rooms you need to cover don't have suitable outlets, so plan those locations before choosing a pack.

Our room-planning guide covers how many carbon monoxide detectors you need. If you also want smoke detection, compare these plug-in alarms with smoke and carbon monoxide detector combos.

Do phone alerts justify choosing a smart CO alarm?

A smart alarm is useful when remote notifications matter and your home has the required network. The Kidde COPDW uses 2.4 GHz Wi-Fi to send alerts through the Kidde app and integrates with Alexa-enabled devices and Google Home.

Phone alerts add a way to hear about an alarm while away, but they don't replace the local audible warning. If you don't want app setup or connected devices, a non-smart alarm with audible and visual alerts can be a simpler fit.

Choose the COPDW if you'll use remote alerts and can meet its Wi-Fi requirement. Skip it if you want a basic outlet alarm or don't have compatible Wi-Fi.

How should you set up and care for a plug-in CO detector?

Set up a plug-in CO detector by following its manual, checking the power source and backup battery, then using its test control as directed. Take a few minutes to understand the alarm signals before relying on the unit.

First, confirm that the alarm is intended for your voltage and space. Several models in this roundup are designed for standard 120V outlets, and the Kidde COPD and COP state that they are not approved for RV or boat use.

Install the backup batteries in the correct orientation, plug the alarm into a suitable outlet and check its indicators. If you're setting up a smart model, complete the app and Wi-Fi steps in its instructions.

Use the test button according to the manual, and repeat checks at the intervals the manufacturer recommends. The test button checks the alarm function.

It doesn't replace the need for correct placement or replacement when the alarm reaches end of life.

Keep the alarm and its outlet accessible, and pay attention to low-battery or end-of-life signals. Don't silence or remove an alarm just because a sound is inconvenient; identify the signal and follow the instructions for what it means.

For more detail, see our guide to testing a carbon monoxide detector at home. It explains how to use the test button without exposing yourself to a CO source.

What mistakes should you avoid with a plug-in CO alarm?

The most common mistakes are treating backup power as a substitute for AC power, choosing an outlet before planning placement, and ignoring warning signals. A few checks before and after installation can prevent those oversights.

• Assuming every plug-in model has the same backup: Check whether your alarm uses 9V or AA batteries and what the manual says about outage operation.
• Leaving batteries out: Backup only helps if the correct batteries are installed and maintained.
• Blocking the alarm: Avoid placing furniture or other objects where they interfere with access or sound.
• Confusing a test with a real CO event: Use the test button as instructed, and never use vehicle exhaust or another CO source to test.
• Ignoring an end-of-life chirp: Treat it as a signal to check the manual and replace the alarm when required.
• Choosing a smart model without compatible Wi-Fi: The COPDW requires a 2.4 GHz connection for its app notifications.
• Expecting plug-in alarms to fit every location: Check voltage and intended use, especially for travel, RVs or boats.

If an alarm sounds for CO, follow its safety instructions and seek fresh air rather than treating the sound as a routine nuisance. A hush control is for appropriate temporary silencing as described in the manual, not for dismissing a suspected hazard.

Which plug-in carbon monoxide detector should you choose?

Choose the Kidde KN-COPP-3 if you want a CO-level display and Peak Level Memory. Pick the First Alert CO606 for simple one-button controls, its three-pack for multiple rooms, or the Kidde COPDW for app alerts when away.

For a backlit display, choose the First Alert CO615 or Kidde COPD. If a rotating plug or color status lights matter more, compare the Kidde COP models and select the features that fit your outlets and room.

Whichever of these best plug in carbon monoxide detector options you choose, install and maintain it according to its manual. Use our guide to test a carbon monoxide detector at home and plan the number of alarms with our room-by-room CO detector guide.

Our top 3 picks at a glance

1. 1
   Best for display readers

   Kidde Plug-In CO Alarm with Digital Display

   9.0/10 our score

   See it on Amazon
2. 2
   Best for dim rooms

   First Alert Plug-In CO Alarm with Digital Display

   8.6/10 our score

   See it on Amazon
3. 3
   Best for simple controls

   First Alert CO606 Plug-In CO Alarm

   8.5/10 our score

   See it on Amazon

Frequently asked questions

Do plug-in carbon monoxide detectors work during a power outage?

Some plug-in CO alarms include battery backup, which supports monitoring during a power outage. Check the specific model's battery type and follow its manual for setup and replacement.

Backup batteries are for outage coverage, not necessarily long-term operation without power.

Should a plug-in CO detector have a digital display?

A display can show CO information that a basic audible alarm does not, and some models also show a peak level. If you prefer simpler controls, a model such as the First Alert CO606 has a test and silence button without a digital display.

An alarm remains the key warning feature.

Where should I place a plug-in carbon monoxide detector?

Follow the alarm's instructions and local guidance for placement. Several models recommend an alarm on each level of the home and in each bedroom.

Check outlet location and access before choosing a plug-in model.

See our guide to how many carbon monoxide detectors you need for room planning.

How do I test a plug-in CO alarm?

Use the test button as directed in the alarm's manual, and don't use vehicle exhaust or another CO source to test it. Testing checks the alarm function, while it does not replace the need to follow the manufacturer's care and replacement instructions.

Our guide explains how to test a carbon monoxide detector at home.

Is a plug-in CO detector better than a battery model?

A plug-in model suits a room with a well-placed outlet, and battery backup can support operation during an outage. A battery model can offer more placement flexibility where outlets are inconvenient.

Compare the tradeoffs in our plug-in vs battery CO detector guide.