Best Smoke and Carbon Monoxide Detectors of 2023

CR’s take: The First Alert 3120B is a dual-sensor smoke detector, meaning it has both a photoelectric sensor for detecting smoky fires and an ionization sensor for detecting flames. Thanks to its use of both types of sensors, this First Alert receives top scores in our flaming fire and smoldering fire tests. It’s hardwired with a battery backup, which makes it a good candidate for newer or remodeled homes that have wiring for detectors, and it features a hush button to silence nuisance alarms. It can be interconnected with additional detectors so that if one goes off, they all go off and alert you to danger even if you’re in a different room or on a different floor from the fire.

CR’s take: Another top performer in our tests is the Kidde PI2010, which receives high scores in our flaming fire and smoldering fire tests. This hardwired, dual-sensor alarm features a battery backup, a hush button, and the ability to interconnect with other compatible detectors. To determine which other models are compatible with this one, check with Kidde.

CR’s take: The First Alert SA320CN is one of the best battery-powered, dual-sensor detectors in our ratings, receiving high marks in both the flaming fire and smoldering fire tests. It features a hush button and runs on two AA batteries, but it can’t interconnect with other alarms to make them all go off in the event of a fire.

CR’s take: First Alert’s Ultimate Protection SA3210 received top marks for the flaming fire and smoldering fire tests. Like the SA320CN, the SA3210 features a hush button, but instead of two AA batteries, the SA3210 runs on a 10-year lithium battery. It also can’t interconnect with other smoke detectors.

CR’s take: Another good choice for a battery-powered detector is the Kidde PI9010. This top-notch detector receives strong scores in our tests for flaming fires and smoldering fires. It features a hush button and runs on a single 9-volt battery, but it can’t interconnect with other detectors.

CR’s take: The Universal Security Instruments AMIB3051SC is one of the first smoke detectors designed to the latest UL 217 standard for smoke alarms, which makes smoke detectors better at reducing false alarms related to cooking. This model receives high scores in our tests for both flaming fires and smoldering fires, and runs on a built-in 10-year alkaline battery. It also features a hush button, but it can’t interconnect with other detectors.

CR’s take: The hardwired Kidde KN-COSM-IBA CO detector performs very well. It receives Excellent scores in our low-CO-level test and for the accuracy of its CO-level display, and a Very Good rating for its high-CO-level test. The model has the ability to log the highest CO levels it detects—referred to as peak memory—which is good for checking to determine whether there has been a problem when you’ve been away from home for a long period of time. It also has a battery backup and the ability to interconnect with other compatible alarms.

CR’s take: The First Alert CO615 is one of the few plug-in CO detectors in our tests, and it beats out its hardwired and battery-powered brethren, with strong scores in our tests for detecting high and low CO levels quickly, as well as a Very Good rating for the accuracy of its CO level display. It features a battery backup and peak memory (so you can check whether CO levels were high after you’ve been gone for a long period of time).

CR’s take: If you need a battery-powered CO detector, check out the First Alert OneLink SCO501CN. It excels in our tests for detecting high and low CO levels, as well as for the accuracy of its CO readings. When the alarm detects CO, an 85-decibel siren and voice alarm (with 11 programmable locations) indicates where and what the development is. Aside from voice alerts, this model features the ability to wirelessly interconnect with other First Alert-enabled alarms. The alarm has a peak memory feature, which logs the highest CO reading so you can see if there was a problem while you were away from home.

CR’s take: If you need a hardwired combination detector, the Universal Security Instruments AMICH3511SC is your best bet. It performs excellently in our low-CO-level test, as well as in our smoldering fire and flaming fire tests. It earned a Good score for detecting high CO levels, too. It’s rated to protect against smoke, fire, and carbon monoxide, and it comes with a sealed battery that should last for 10 years.

CR’s take: The Universal Security Instruments MIC3510SB is one of few combination detectors that has both photoelectric and ionization sensors for smoldering and flaming fires (most combo models have only one of the two) in addition to a CO sensor. As a result, this USI detector is the only combination model to perform well across all our smoke and CO tests. This model runs on a sealed, 10-year battery. It features a hush button. However, it can’t interconnect with other detectors.

CR’s take: For a smart smoke and CO detector that connects directly to WiFi, check out the First Alert Onelink Smart 1042135. This model receives strong scores in all our tests, with the exception of flaming fires because it lacks an ionization sensor. If you go with this detector, you may want to also consider purchasing a battery-powered ionization smoke detector, such as the Kidde RF-SM-DC. This First Alert comes in both battery-powered and hardwired versions, can interconnect with other compatible detectors, and works with Amazon Alexa and Apple HomeKit/Siri for voice and app control.

CR’s take: The Google Nest Protect is another WiFi-enabled combination smoke-CO detector that performs well in our tests. It receives strong scores in our tests for low CO levels and smoldering fires, as well as a Good rating for detecting high CO levels. But like the First Alert Onelink above, it falls short in our flaming fire test. If you go with this detector, you may want to also consider purchasing a battery-powered ionization smoke detector, such as the Kidde RF-SM-DC. The Google Nest Protect comes in both battery-powered and hardwired versions and can interconnect with additional Nest Protects.