Verdict
All guidesMethodologyAboutContact
The Best 5Reviewed by Mike Hun·May 17, 2026

Best Carbon Monoxide Detectors

Top 5 carbon monoxide detectors reviewed and ranked.

Quick answer

First Alert CO710 Carbon Monoxide Alarm is our top pick for carbon monoxide detectors — an averaged 4.5/5 across 2 published reviews at about $46. Runner-up: Kidde Hardwired Smart Smoke and Carbon Monoxide Detector (~$75).

Read the First Alert CO710 Carbon Monoxide Alarm review →$46 · Check Price on Amazon

At a glance

Tap any product for the full review
1First Alert CO710 Carbon Monoxide AlarmTop Score
(2 sources)
$46Best for: Travelers and low-maintenance users
$46 · Check Price on Amazon
2Kidde Hardwired Smart Smoke and Carbon Monoxide Detector
(4 sources)
$75Best for: Users prioritizing traditional safety
$75 · Check Price on Amazon
3Klein Tools ET110 CO Meter
(4 sources)
$204Best for: HVAC technicians needing precision
$204 · Check Price on Amazon
4First Alert SC5 Smart Smoke and Carbon Monoxide Alarm
(4 sources)
$111Best for: Smart home users wanting integration
$111 · Check Price on Amazon
5Kidde Smoke and Carbon Monoxide Detector
(2 sources)
$49Best for: Users wanting basic smart alerts
$49 · Check Price on Amazon
Verdict is reader-supported. As an Amazon Associate we earn from qualifying purchases. Some links on this page are affiliate links — if you click through and buy, we may earn a small commission at no extra cost to you. Our ratings are sourced from independent publications, not sponsors.
Reviews aggregated from
TechHiveFirstalertstoreFirstalertco710carbonmonoxidedetectCostcoGood HousekeepingReviewkiddehardwiredkiddeappenabledGlobaltestsupplyAztesters

The full ranking

How we rank →
First Alert CO710 Carbon Monoxide Alarm
#1 · Top Score
Best for: Travelers and low-maintenance users
First Alert CO710 Carbon Monoxide Alarm
from 2 sources$46

The First Alert CO710 Carbon Monoxide Alarm features a 10-year sealed battery that eliminates the need for battery replacements, according to reviewers. Users praise its digital display and ease of installation. Consumer Reports recommends it as a reliable option for home safety. Some users note that testing requires firm pressing, and there's debate about optimal placement. This alarm is ideal for those seeking a low-maintenance, long-lasting CO detector.

Strengths
  • — 10-year sealed battery eliminates need for battery replacement
  • — Digital display shows carbon monoxide levels clearly
Watch-outs
  • — Requires firm pressing to test function
  • — Some users report conflicting information about optimal placement
$46 · Check Price on AmazonFull review →vs. Kidde Hardwired Smart Smoke and Carbon Monoxide Detector →
Kidde Hardwired Smart Smoke and Carbon Monoxide Detector
#2
Best for: Users prioritizing traditional safety
Kidde Hardwired Smart Smoke and Carbon Monoxide Detector
from 4 sources$75

The Kidde Hardwired Smart Smoke and Carbon Monoxide Detector offers comprehensive safety with a 10-year battery life and advanced detection technology that's 25% faster and 3X more precise than average smoke alarms. TechHive reviewer Christopher Null praised its reliable performance and interconnect capabilities but noted it lacks smart home integration and is pricey for a non-smart model. The unit includes voice alerts and can interconnect up to 24 devices, though installation requires basic wiring knowledge. Best for users prioritizing traditional safety features over smart connectivity.

Strengths
  • — 10-year lifespan with non-removable battery
  • — Fast smoke detection (25% faster than average)
Watch-outs
  • — No smart home connectivity or Wi-Fi features
  • — Busy design that juts out 2 inches from wall/ceiling
$75 · Check Price on AmazonFull review →vs. First Alert CO710 Carbon Monoxide Alarm →
Klein Tools ET110 CO Meter
#3
Best for: HVAC technicians needing precision
Klein Tools ET110 CO Meter
from 4 sources$204

The Klein Tools ET110 is a handheld carbon monoxide meter designed for HVAC technicians to detect unsafe CO levels. Reviewers noted its dual-color indicator light, audible and visual alarms, and backlit display with large digits for clear readings. The device features automatic zero-calibration at power-on, a 3-minute diagnostic self-test, and a 5-year expected sensor lifetime. It measures CO from 0 to 1000 ppm with 1 ppm resolution and includes temperature measurements. However, some reviewers pointed out its limited humidity tolerance and narrow storage temperature range, which may affect usability in extreme climates.

Strengths
  • — Backlit monochrome LCD display with large digits for clear readings
  • — Audible and visual alarms at 35 ppm and 200 ppm levels
Watch-outs
  • — RH limit of <85% may present problems in very humid climates
  • — Storage temperature range only 23°F to 131°F (-5°C to 55°C)
$204 · Check Price on AmazonFull review →vs. First Alert CO710 Carbon Monoxide Alarm →
First Alert SC5 Smart Smoke and Carbon Monoxide Alarm
#4
Best for: Smart home users wanting integration
First Alert SC5 Smart Smoke and Carbon Monoxide Alarm
from 4 sources$111

The First Alert SC5 Smart Smoke and Carbon Monoxide Alarm offers a modern design and app-based control that enhances home safety. Bob Vila reviewers praised its simple installation, one-button silence feature, and Google Home integration. Isaac from Smart Home Explained noted the device's superior build quality and smooth app setup process. However, the $130 price point and limited brand compatibility for interconnect features are drawbacks. This alarm suits users seeking smart home integration and improved user experience over traditional detectors, but those with existing non-First Alert systems may miss out on full network coverage.

Strengths
  • — Easy installation with pre-installed batteries and voice-guided setup
  • — One-button silence feature improves user experience during false alarms
Watch-outs
  • — Price is significantly higher than standard alarms at around $130 per unit
  • — Limited interconnect compatibility with other brands like Kidde and Nest Protect
$111 · Check Price on AmazonFull review →vs. First Alert CO710 Carbon Monoxide Alarm →
Kidde Smoke and Carbon Monoxide Detector
#5
Best for: Users wanting basic smart alerts
Kidde Smoke and Carbon Monoxide Detector
from 2 sources$49

The Kidde Ring Smart Smoke + CO Alarm offers reliable dual detection with smartphone notifications, according to PCMag's review. While praised for its ease of installation and long battery life, the device received criticism for its limited smart home integration capabilities. Consumer Reports recommends it as a solid choice for basic smoke and carbon monoxide protection, though it lacks advanced automation features found in higher-end models. This detector is best suited for users seeking straightforward safety monitoring without complex smart home integration.

Strengths
  • — Smart alerts with smartphone notifications
  • — Easy installation and setup
Watch-outs
  • — Limited smart home integration with only basic automation support
  • — No built-in siren override for testing
$49 · Check Price on AmazonFull review →vs. First Alert CO710 Carbon Monoxide Alarm →

Spec comparison

5 products
SpecFirst Alert CO710 Carbon Monoxide AlarmKidde Hardwired Smart Smoke and Carbon Monoxide DetectorKlein Tools ET110 CO MeterFirst Alert SC5 Smart Smoke and Carbon Monoxide AlarmKidde Smoke and Carbon Monoxide Detector
Detection TypeElectrochemical sensorDual SensorCarbon MonoxideSmart Smoke and CO AlarmSmoke and Carbon Monoxide
Power SourceBattery operatedHardwired4 x AAA batteriesBuilt-in lithium backup batteryHardwired with 10-year integrated battery
Battery Life10 years10 years—10-year sealed lithium battery10 years
DisplayDigitalLED indicatorBacklit monochrome LCDLED light ring—
Alarm Thresholds85 dB—35 ppm and 200 ppm levels70 PPM CO concentration—
FeaturesCarbon monoxide detectionVoice alerts, false alarm reductionAudible and visual alarms, Backlit LCD, Auto-Power OffApp-based testing, voice alerts, one-button silenceVoice alerts, interconnectable, LED indicator
Connectivity—Wi-Fi, Ring App, Amazon Alexa, Google Home—Google Home compatibleWi-Fi

Frequently asked questions

What is the best carbon monoxide detector?
First Alert CO710 Carbon Monoxide Alarm is our top pick for carbon monoxide detectors, with an averaged rating of 4.5/5 from 2 published reviews. The First Alert CO710 Carbon Monoxide Alarm features a 10-year sealed battery that eliminates the need for battery replacements, according to reviewers. Users praise its digital display and ease of installation. Consumer Reports recommends it as a reliable option for home safety. Some users note that testing requires firm pressing, and there's debate about optimal placement. This alarm is ideal for those seeking a low-maintenance, long-lasting CO detector.
What's the runner-up if the top pick is unavailable?
Kidde Hardwired Smart Smoke and Carbon Monoxide Detector (around $75) rates 4.4/5 in our analysis. The Kidde Hardwired Smart Smoke and Carbon Monoxide Detector offers comprehensive safety with a 10-year battery life and advanced detection technology that's 25% faster and 3X more precise than average smoke alarms. TechHive reviewer Christopher Null praised its reliable performance and interconnect capabilities but noted it lacks smart home integration and is pricey for a non-smart model. The unit includes voice alerts and can interconnect up to 24 devices, though installation requires basic wiring knowledge. Best for users prioritizing traditional safety features over smart connectivity.
How does Verdict rank these products?
Every rating on Verdict is the numerical average of scores published by independent review sites, YouTube reviewers, and Reddit buyer reports. No editor adjusts the order — the ranking is whatever the source data produces. See our methodology page for the full process.
When was this guide last updated?
This guide was last re-checked in May 2026. We re-run our research pipeline for each category on a rolling basis so prices and rankings reflect current market reality.

Related guides

Browse all →