Best Rated Carbon Monoxide Detector (2026): 6 Popular CO Alarms

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The best rated carbon monoxide detector picks are alarms that many owners trust year after year, from simple plug-ins to sealed-battery combos.

We focused on 6 well-reviewed alarms and compared their features.

Quick Answer: The Best Rated Carbon Monoxide Detector

• Best Rated Overall: Kidde Carbon Monoxide Detector, Plug-in with AA Battery Backup, 85 dB Alarm, 3rd Edition
• Best Rated Battery: First Alert Battery Carbon Monoxide Alarm CO400
• Best Rated Combo: X-Sense Smoke Detector Carbon Monoxide Detector Combo, SC07, 1-Pack
• Best Rated AA Alarm: Kidde Carbon Monoxide Detector, AA Battery Powered CO Alarm with LEDs
• Best Rated Battery Combo: First Alert Battery Combination Smoke & Carbon Monoxide Alarm SMCO100
• Best Rated Hardwired: First Alert Hardwire Combination Smoke & Carbon Monoxide Alarm SMICO100-AC

The Kidde Plug-In CO Detector (AA Backup) is our best rated carbon monoxide detector pick. The First Alert CO400 Battery CO Alarm is a well-reviewed battery pick, and the X-Sense SC07 Smoke & CO Alarm is a popular combo.

Best Rated Carbon Monoxide Detector Comparison Table

The 6 Best Rated Carbon Monoxide Detectors

Each pick below was compared on sensor type, power source, alerts, certification and value.

Best Rated Overall

Kidde Carbon Monoxide Detector, Plug-in with AA Battery Backup, 85 dB Alarm, 3rd Edition

9.1/10 GR Score ⓘ

Check Price on Amazon.com ↗

1The Kidde plug-in CO detector runs from a standard 120V outlet with two AA batteries as backup during outages.

👍 Pros & Cons

Pros

• Plug-in with 2-AA battery backup
• Peak Level Memory
• Test-Hush button

Cons

• No digital readout

📄 Detailed Review

• Type: Plug-in CO alarm
• Includes: Alarm + 2 AA batteries
• Key feature: 120V plug-in, 2-AA backup, peak level memory

It sounds an 85 dB alarm, and Peak Level Memory records the last time CO was detected or the unit was tested.

It is the simplest dependable CO alarm for most homes.

Check Kidde Plug-In CO Detector (AA Backup) Price on Amazon

Best Rated Battery

First Alert Battery Carbon Monoxide Alarm CO400

8.9/10 GR Score ⓘ

Check Price on Amazon.com ↗

2The First Alert CO400 is a battery-powered CO alarm with an electrochemical sensor and an 85 dB siren.

👍 Pros & Cons

Pros

• Battery-powered, works in outages
• End-of-life chirp
• 5-year limited warranty

Cons

• No digital readout

📄 Detailed Review

• Type: Battery CO alarm
• Includes: Alarm + batteries
• Key feature: Electrochemical sensor, 85 dB

An end-of-life chirp tells you when to replace it, and it carries a 5-year limited warranty.

It is a budget favorite.

Check First Alert CO400 Battery CO Alarm Price on Amazon

Best Rated Combo

X-Sense Smoke Detector Carbon Monoxide Detector Combo, SC07, 1-Pack

8.7/10 GR Score ⓘ

Check Price on Amazon.com ↗

3The X-Sense SC07 pairs a photoelectric smoke sensor with an electrochemical CO sensor in one alarm.

👍 Pros & Cons

Pros

• 10-year sealed battery
• Photoelectric smoke + electrochemical CO
• Certified to UL 217 and UL 2034 (maker claim)

Cons

• Standalone, no interconnect

📄 Detailed Review

• Type: Smoke and CO combo
• Includes: Alarm + bracket
• Key feature: 10-year sealed battery, UL 217 and UL 2034

It runs on a sealed 10-year battery and mounts on a wall or ceiling without wiring.

It is a value 10-year combo.

Check X-Sense SC07 Smoke & CO Alarm Price on Amazon

Best Rated AA Alarm

Kidde Carbon Monoxide Detector, AA Battery Powered CO Alarm with LEDs

8.7/10 GR Score ⓘ

Check Price on Amazon.com ↗

4This Kidde CO alarm runs on two AA batteries, so it works anywhere and during power failures.

👍 Pros & Cons

Pros

• No wiring or outlet needed
• Peak Level Memory
• Wall or tabletop

Cons

• Batteries need changing

📄 Detailed Review

• Type: Battery CO alarm
• Includes: Alarm + 2 AA batteries
• Key feature: 2-AA batteries, LEDs, peak level memory

It uses an electrochemical sensor, an 85 dB alarm and Peak Level Memory.

It is a flexible, low-cost choice.

Check Kidde Battery CO Detector (AA) Price on Amazon

Best Rated Battery Combo

First Alert Battery Combination Smoke & Carbon Monoxide Alarm SMCO100

8.6/10 GR Score ⓘ

Check Price on Amazon.com ↗

5The First Alert SMCO100 combines smoke and CO detection in one battery-operated alarm.

👍 Pros & Cons

Pros

• Smoke and CO in one
• Precision Detection reduces cooking alarms (maker claim)
• End-of-life warning

Cons

• Batteries need changing

📄 Detailed Review

• Type: Smoke and CO combo
• Includes: Alarm
• Key feature: Battery, Precision Detection

First Alert’s Precision Detection is designed to cut cooking nuisance alarms.

It is a value combo pick.

Check First Alert SMCO100 Smoke & CO Alarm Price on Amazon

Best Rated Hardwired

First Alert Hardwire Combination Smoke & Carbon Monoxide Alarm SMICO100-AC

8.5/10 GR Score ⓘ

Check Price on Amazon.com ↗

6The First Alert SMICO100-AC is a hardwired smoke and CO alarm with battery backup.

👍 Pros & Cons

Pros

• Interconnects with compatible alarms
• Quick Connect plug
• Battery backup

Cons

• Needs existing wiring

📄 Detailed Review

• Type: Hardwired smoke and CO
• Includes: Alarm
• Key feature: Hardwired, battery backup, interconnect

When one alarm sounds, all compatible interconnected alarms sound too.

It is the pick for replacing wired alarms.

Check First Alert SMICO100-AC Hardwired Smoke & CO Price on Amazon

How We Chose the Best Rated Carbon Monoxide Detector

To choose the best rated carbon monoxide detector, we compared popular CO alarms and smoke-and-CO combos on Amazon by power source, display, alerts, listed standards and owner feedback.

CDC advises installing battery-operated or battery back-up CO detectors near every sleeping area; see the CDC carbon monoxide poisoning basics.

Product details in this guide are based on manufacturer specifications and verified owner feedback. Read more on our How We Test page.

Buying Guide: Reading Alarm Reviews

Keep these points in mind before you buy.

What reviews tell you

Look for comments on false alarms, chirping, battery life and how easy testing is.

Look for UL 2034

Home CO alarms in the US are tested to UL 2034. Combo alarms also list UL 217 for smoke.

Replace on schedule

CDC says to replace a CO detector following the maker’s instructions or every 5 years. Most alarms chirp at end of life; 10-year models are replaced as a whole unit.

Before Trusting a Rating

Check four things:

• UL 2034 listing.
• Recent reviews.
• Manufacture date.
• Warranty length.

Quick answers about the best rated carbon monoxide detector.

Frequently Asked Questions

What is the best rated carbon monoxide detector?

The best rated carbon monoxide detector picks are the Kidde plug-in with AA backup and the First Alert CO400.

Why do some reviews mention chirping?

Chirps usually mean low battery or end of life.

Are ratings a sign of accuracy?

Look for UL 2034 testing for that.

What is the manufacture date for?

It helps you track the alarm’s age.

Should I trust old reviews?

Check recent ones too, since models change.

Final Verdict

Our final pick for the best rated carbon monoxide detector is the Kidde Plug-In CO Detector (AA Backup). Choose the First Alert CO400 Battery CO Alarm if you want a battery pick, or the X-Sense SC07 Smoke & CO Alarm as a popular combo.

Related Guides

More home safety guides:

• Best Carbon Monoxide Detector
• Best Alternative to Carbon Monoxide Detector
• Best Budget Carbon Monoxide Detector
• Best Quality Carbon Monoxide Detector
• Best Emergency Power Supply for Home

Product details are based on manufacturer specifications at the time of writing. Prices and availability change often, so check Amazon for the latest price.