A collection of various models of smoke and carbon monoxide alarms, including the best smoke and CO detectors from brands like First Alert and Kidde, ensuring optimal home safety.

Best Smoke and CO Detectors of 2024

When it comes to ensuring the safety and well-being of your family within the comfort of your home, staying vigilant against the threats posed by fires and carbon monoxide (CO) is paramount.

Dubbed the “silent killer” due to its colorless, odorless nature, carbon monoxide can leak from everyday appliances like stoves, heating systems, and even blocked chimneys, posing a serious risk to health and life. This is where investing in the best smoke and CO detector becomes not just a choice but a necessity.

Smoke and carbon monoxide detectors are designed to serve as the first line of defense against these invisible dangers. By combining the functionality of a smoke alarm with carbon monoxide detectors, these units offer comprehensive protection.

Photoelectric sensors in these detectors are finely tuned to detect the presence of smoke and CO with greater accuracy and reduced false alarms, allowing for peace of mind especially in sleeping areas where the risk of unnoticed exposure is highest.

Moreover, modern advancements have seen the integration of smart home technology into these life-saving devices. Features like remote notifications and the ability to test the device’s functionality with a simple test button press from your smartphone app, enhance safety measures.

Our Top Picks

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Best Price$17
First Alert 3120B
Kidde PI2010
First Alert SA320CN
First Alert Ultimate Protection SA3210
Kidde PI9010
$169 (x2)View

Best Overall: First Alert 3120B

Imagine a device that whispers safety into your home, standing guard against the silent threats that linger unseen. The First Alert 3120B is not just an alarm; it’s your family’s sentinel against the unpredictable dangers of smoke and carbon monoxide. This marvel of technology is designed to detect the earliest whispers of danger, ensuring that your peace of mind is uninterrupted.

The First Alert 3120B smoke alarm features dual sensors and an intelligent sensing technology for reliable fire detection, qualifying as one of the best smoke and CO detectors on the market.


  • Dual Detection: Photoelectric and ionization sensors for comprehensive threat detection.
  • Interconnectivity: Can link up to 18 devices for whole-home coverage.
  • Battery Backup: Ensures functionality even during power outages.
  • 85 dB Alarm: Loud enough to wake even the deepest sleeper.
  • Easy Installation: Simple setup for stress-free protection.
  • Test/Silence Button: Easily test functionality or silence false alarms.
  • Low Battery Alert: Audible and visual warnings when batteries need replacement.
  • 10-Year Warranty: Long-term reliability and peace of mind.
Pros Dual Detection Interconnectivity 10-Year Warranty
Cons No CO Detection No Safety Light Installation Limits

Who Is It For?

The First Alert 3120B is tailor-made for the modern homeowner who values safety, convenience, and peace of mind. Whether you’re a tech-savvy individual looking to integrate a smart, interconnected safety system into your home, or a concerned parent wanting to ensure the sleeping area is shielded against both smoke and carbon monoxide, this device is for you.

Its dual sensors offer comprehensive detection of both smoldering and fast-flaming fires, making it ideal for placement in every key area of your home—from the kitchen to the bedrooms. The ability to connect up to 18 devices means that larger homes can have seamless protection, with every alarm sounding off simultaneously in the event of a fire, ensuring that everyone, no matter where they are in the house, is alerted to danger.

The First Alert 3120B’s blend of advanced technology, ease of use, and reliability makes it a cornerstone in the defense against the threats of fire and smoke, embodying the essence of a smart home safety solution.

Best Advanced Features: Kidde PI2010

The Kidde PI2010 Smoke Alarm stands as a beacon of safety in the modern home, offering unparalleled protection against fire hazards. With a blend of ionization and photoelectric sensors, this dual-sensor alarm provides comprehensive detection of both fast-flaming and slow-smoldering fires.

The Kidde PI2010 is a prominent smoke and CO detector with a dual-sensor system and a test/hush button, designed to offer superior protection and peace of mind.


  • Power Source: 120VAC with 9V battery backup
  • Sensors: Dual (Ionization and Photoelectric)
  • Audio Alarm: 85dB at 10ft
  • Temperature Range: 40˚F to 100˚F
  • Humidity Range: Up to 85% relative humidity
  • Size: 5.75” diameter x 1.8” depth
  • Weight: 0.4 lb
  • Interconnects: Up to 24 Kidde devices​​​​.
Pros Dual-Sensor Technology Interconnectivity Capability Tamper-Resistant
Cons Hardwire Installation Limited Temperature Range Battery Dependency

Who Is It For?

The Kidde PI2010 Smoke Alarm is an essential safeguard for any homeowner seeking to enhance their fire safety measures. Ideal for those who appreciate the peace of mind that comes with advanced technology, this alarm system suits homes of any size, thanks to its capability to interconnect with up to 24 devices.

Whether you live in a cozy apartment or a sprawling estate, the PI2010 offers the flexibility and reliability to protect your space. Its dual-sensor technology ensures that both quick-burning and slow-smoldering fires are detected promptly, making it a critical addition for families, tech enthusiasts, and safety-conscious individuals alike.

Easy to install for those familiar with basic wiring, it represents a robust solution for ensuring the safety and security of your loved ones and property.

Best Budget: First Alert SA320CN

Meet the First Alert SA320CN: a budget-friendly guardian for your home. This dual-sensor smoke alarm is designed to detect both fast-flaming and slow-smoldering fires, offering comprehensive protection without breaking the bank. With easy installation and a user-friendly interface, it’s a reliable choice for safety-conscious individuals looking for peace of mind on a budget.

First Alert SA320CN represents cutting-edge smoke and CO detection with its intelligent sensing technology and battery backup, making it a best smoke and CO detector choice for homeowners.


  • Power Source: Battery Operated
  • Battery Type: Two AA
  • Sensor Type: Photoelectric and Ionization
  • Optipath 360° Technology: Ensures complete smoke detection coverage
  • Intelligent Sensing Technology: Reduces nuisance alarms
  • Noise Output: 85 dB in a T3 Pattern
  • Single Button: For silence and test functions
  • Dimensions: 5 x 2 x 5 inches
  • Weight: 0.9 lbs
Pros Dual Sensor Technology Nuisance Resistance Easy Installation
Cons Battery Replacement Limited Features No Smart Connectivity

Who Is It For?

The First Alert SA320CN is perfect for homeowners, renters, and small business owners seeking a cost-effective yet reliable smoke alarm system. It’s especially suitable for those who prefer straightforward, no-fuss safety solutions. Whether you live in a compact city apartment or a spacious suburban home, this smoke alarm offers essential protection against fire hazards.

With dual-sensor technology, it caters to a wide range of fire types, ensuring that you and your loved ones are alerted at the first sign of danger. Easy to install and maintain, it’s an ideal choice for anyone looking to enhance their fire safety measures without overspending​​.

Best Battery Life: First Alert Ultimate Protection SA3210

The First Alert Ultimate Protection SA3210 stands out as a beacon of safety in your home, offering unparalleled peace of mind against the silent killer of smoke and carbon monoxide. Its battery-powered design ensures protection around the clock, with a decade-long battery life that eliminates the need for frequent replacements.

Showcasing the First Alert Ultimate Protection SA3210, this best smoke and CO detector is equipped with advanced sensors for enhanced home safety.


  • Power Source: Battery Operated with a 10-Year Sealed Lithium Battery
  • Sensors: Photoelectric and Ionization for dual fire detection
  • Optipath 360° Technology: Ensures direct access to the smoke sensor
  • Intelligent Sensing Technology: Reduces false alarms
  • Noise Output: Loud 85 dB alarm in a T3 Pattern
  • Single Button Operation: Simplifies testing and silencing
  • Mounting: Perfect Mount for secure and easy installation
  • Weight: .54 lbs, for easy placement anywhere in the home
Pros Dual Sensor Technology 10-Year Battery Easy Installation
Cons Higher Cost Limited Features Bulkier Design

Who Is It For?

The First Alert Ultimate Protection SA3210 is perfect for homeowners and renters alike who prioritize the safety and security of their living spaces. Ideal for those looking for a long-term solution without the hassle of frequent battery replacements, this device offers a decade of peace of mind.

It’s particularly suited for individuals who appreciate the latest in smoke and carbon monoxide detection technology, including dual sensors and intelligent sensing to minimize false alarms.

Whether you’re integrating this into a comprehensive smart home system or simply seeking to protect your family in the most critical areas like sleeping areas, the SA3210 is designed to meet your needs with ease and reliability.

Best Basic Protection: Kidde PI9010

Introducing the Kidde PI9010, the guardian of your home’s safety. This battery-operated smoke alarm is a powerhouse in a compact package, blending advanced fire detection technology with user-friendly features.

Its dual-sensor capability ensures your peace of mind, detecting both smoldering and flaming fires quickly. Easy to install and equipped with a Hush® feature to silence nuisance alarms, the PI9010 is your first line of defense against fire hazards, ensuring continuous protection even during power outages.

The Kidde PI9010 smoke and CO detector is featured with battery backup and test-hush feature, ensuring it’s one of the best for smoke and carbon monoxide detection.


  • Power Source: 9V Battery
  • Sensor Type: Dual (Ionization and Photoelectric)
  • Audio Alarm: 85dB at 10ft
  • Temperature Range: 40°F to 100°F
  • Humidity Range: Up to 85% RH
  • Dimensions: 5.75” diameter x 1.8” depth
  • Weight: 1lb
  • Warranty: 10-year limited
Pros Dual-Sensor Technology Hush® Feature Battery Operated
Cons No Interconnects Battery Replacement Single Unit

Who Is It For?

The Kidde PI9010 is perfect for homeowners seeking reliable, no-fuss fire protection. Its dual sensors offer comprehensive detection of fast-flaming and slow-smoldering fires, making it ideal for a wide range of living spaces, from apartments to family homes.

The simplicity of battery operation, combined with the Hush® feature for silencing false alarms, makes it a great choice for families, the elderly, or anyone wanting straightforward, effective fire safety measures. With its ease of installation and maintenance, it’s also suited for renters who need portable, dependable fire detection solutions.

The Kidde PI9010 offers peace of mind with its blend of advanced safety features and simple, user-friendly operation, ensuring everyone can stay safe without needing technical expertise.

Best Long-Term Reliability: USI AMIB3051SC

The USI AMIB3051SC is a cutting-edge smoke and fire alarm designed to offer unparalleled protection for your home. With a 10-year sealed battery, this device ensures a decade of peace of mind against the threats of fast flaming and slow smoldering fires.

Its innovative Sensing Plus® technology combines the best of photoelectric and ionization detection methods, safeguarding your home with accuracy and reliability. Compact and tamper-proof, the AMIB3051SC is the guardian your family deserves.

The USI AMIB3051SC combines smoke and carbon monoxide detection in one device, recognized as one of the best detectors for ensuring safety against fire and gas threats.


  • Type: 10 Year Battery Combination Detector
  • Technology: Sensing Plus® Multi-Criteria Detection
  • Battery: 10 Year Permanent Power, Lithium-Free Alkaline
  • Alarm Volume: Loud 85 dB
  • Dimensions: 5.63 x 5.63 x 1.75 inches
  • Weight: 0.42 lbs
  • Warranty: 10-Year Limited on Battery & Alarm
  • Standards Compliance: UL 217 8th Edition, California State Fire Marshal Approved
Pros Multi-Criteria Detection 10-Year Battery Tamper-Proof Design
Cons Limited Compatibility No Digital Display Single Installation Method

Who Is It For?

The USI AMIB3051SC is perfect for homeowners who prioritize long-term reliability and safety in a smoke and fire alarm. Its 10-year battery life and maintenance-free design make it an ideal choice for those looking to install it and rest easy, knowing they are protected.

Whether you’re updating your home’s safety features or installing a smoke and fire alarm for the first time, the AMIB3051SC provides robust protection with its dual sensor capabilities, making it an excellent choice for families, landlords, and property managers aiming to uphold the highest safety standards in residential settings​​​​​​.

Best 2 Packs: Kidde KN-COSM-IBA

Meet the Kidde KN-COSM-IBA: a state-of-the-art safety device designed to protect you and your family from the invisible dangers of carbon monoxide (CO) and the ever-present threat of fire.

This hardwired combination smoke and CO alarm with a voice warning system ensures your home remains a safe haven. Compact and efficient, it’s an essential addition to any household, offering peace of mind with its advanced detection technologies.

Kidde's KN-COSM-IBA offers comprehensive protection as a best smoke and CO detector, featuring voice alerts and a peak level memory for carbon monoxide incidents.


  • Power Source: 120VAC, 60Hz with a 2 AA battery backup
  • Sensor Types: Ionization (smoke), Electrochemical (CO)
  • Audio Alarm: 85dB at 10 feet
  • Operating Conditions: 40˚F to 100˚F, 10%-95% relative humidity, non-condensing
  • Size & Weight: 5.6” diameter x 1.8” depth, 1 lb.
  • Interconnectivity: Connects up to 24 Kidde devices
  • Warranty: 10 years
  • Special Features: Voice alerts, Peak Level Memory, Hush™ feature
Pros Voice alerts Interconnectivity Peak Level Memory
Cons Limited sensor type Hardwired installation Ionization sensor concerns

Who Is It For?

The Kidde KN-COSM-IBA is the perfect safety solution for homeowners seeking advanced protection against fire and carbon monoxide threats. It’s especially suited for families residing in interconnected homes or apartments, where a single source of danger could potentially affect multiple units.

With features like voice alerts for clear danger identification and the ability to connect with up to 24 Kidde devices, this alarm system is ideal for those who prioritize safety and convenience.

Whether you’re upgrading your existing fire and CO detection system or installing a new one, the KN-COSM-IBA offers reliability and peace of mind. Its easy installation and comprehensive coverage make it a top choice for ensuring the well-being of your loved ones​​​​.

What I Wish I Knew Before I Got The Best Smoke and CO Detector?

  1. Lifespan Matters: Some CO detectors have longer lifespans than others, ranging from 1 to 10 years, which can significantly impact replacement frequency and long-term costs​​.
  2. Installation Ease: Many users appreciate detectors that are easy to install, with some models requiring no drilling or hardwiring, thus making setup straightforward​​.
  3. Alert Types: Detectors vary in how they alert you, with some offering visual and auditory alerts, which is crucial for people with hearing impairments​​.
  4. Battery vs. Hardwired: Battery-operated units ensure continuous operation during power outages, but hardwired models can interconnect with other detectors for enhanced safety​​​​.
  5. Smart Features: Smart detectors offer remote notifications and silencing through apps, though some lack basic features like a silence button on the device itself​​.
  6. Sensor Type: The type of sensor (electrochemical for CO and photoelectric for smoke) can affect detection accuracy and response time to different fire types​​.
  7. Warranty Coverage: Warranties range from 1 to 10 years, influencing the perceived reliability and support for the device​​​​.
  8. Special Features for the Hearing Impaired: Some detectors come with features like strobe lights to cater to users with hearing loss, ensuring they’re alerted during emergencies​​.
  9. Display and Voice Alerts: A digital display can be helpful for monitoring CO levels, but not all models include this feature. Voice alerts can offer clear hazard identification​​​​.
  10. Consideration for Placement: Proper installation is crucial to avoid false alarms, with guidelines suggesting avoidance of places like above stoves or near bathrooms to prevent steam-triggered alerts​​.

Are combined smoke and CO detectors good?

Combined smoke and carbon monoxide detectors are an efficient solution for enhancing safety within your home. These devices offer the dual functionality of detecting both smoke, which can be indicative of a fire, and carbon monoxide (CO)—the silent killer—a gas that is colorless, odorless, and potentially deadly.

The benefits of these combined detectors include space-saving and cost-effectiveness, as they consolidate two critical safety devices into one unit. They come in various types, including battery-operated and hardwired models, catering to different preferences and requirements.

For instance, Kidde offers a range of these detectors, some featuring 10-year batteries, intelligent wire-free alarms, and options for hardwired installation, ensuring that there’s a solution for every type of home and preference​​​​. Such devices are particularly valuable in sleeping areas, where the risk of undetected CO exposure is higher during sleep.

By installing a combined smoke and carbon monoxide detector, you can protect your family against both the immediate danger of fire and the silent threat of CO poisoning, aligning with smart home safety practices.

How many carbon monoxide detectors do I need in my house?

To safeguard your home against the “silent killer,” it is recommended to install a “carbon monoxide detector” on every level, including the basement, and near sleeping areas. This strategic placement ensures early detection, allowing you to protect your family effectively.

Equipping your home with these detectors, especially “battery operated” units, offers a layer of safety against this invisible hazard, ensuring peace of mind and enhancing your smart home’s security.

Where is the best place to put a smoke and carbon monoxide detector?

The optimal placement for a smoke and carbon monoxide detector is on every level of your home, including the basement, to ensure comprehensive coverage.

Specifically, position the detector in the hallway leading to each bedroom to safeguard sleeping areas, especially since carbon monoxide poisoning is particularly dangerous at night.

For homes with attached garages, install a detector within 10 feet of the garage door to monitor any carbon monoxide ingress from car exhaust.

Additionally, ensure the alarm is loud enough to wake you, and place it near sleeping areas if you have only one detector​​​​​​.

Emily Thompson is a passionate technology enthusiast and skilled reviewer, deeply knowledgeable about every niche within the tech world. Emily's expertise and keen eye for detail make her an invaluable guide for anyone looking to understand or purchase tech products. The products listed in this article were chosen according to our expert tests.