Google Nest Protect stands out as the best overall smart smoke and carbon monoxide detector due to its reliable sensor technology and mobile integration. For those already in specific ecosystems, SimpliSafe and Ring are recommended for seamless security system operation. X-Sense is a frequently suggested alternative for budget-conscious homeowners who want smart alerts and long battery life without a high price point.
3X-SenseAn excellent choice for budget-conscious buyers who need reliable smart alerts. These detectors offer a long, 10-year battery life and easy wireless setup, providing a high-value option for monitoring multiple rooms economically.72%
4Google NestThe top pick for general home use due to its proven sensor reliability, clear voice alerts, and intuitive smartphone integration, making it a dependable choice for most households regardless of other smart gear.53%
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Recommended in · Sep 6 – Sep 26, 2026
First AlertChatGPT Search6 of 6 answersGoogle AI Mode4 of 4 answers
KiddeChatGPT Search6 of 6 answersGoogle AI Mode4 of 4 answers
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Google NestChatGPT Search3 of 6 answersGoogle AI Mode2 of 4 answers
When choosing a smart smoke and carbon monoxide detector, there is no single absolute best choice for every household; instead, the right model depends on your existing smart home ecosystem . Major tech reviewers like Wirecutter and CNET widely recommend the Kidde Smart Smoke + Carbon Monoxide Alarm as the top overall pick for its excellent sensor precision and reliability. For those who prefer a premium alternative with flexible ecosystem integration, the First Alert SC5 Smart Smoke & Carbon Monoxide Alarm stands out as a top contender. Meanwhile, the X-Sense XP0A-MR Interconnected Smart Smoke and CO Alarm offers a highly capable and budget-friendly whole-home system.[6]
Best Overall : Widely praised by experts for its upgraded, highly precise photoelectric sensors that reduce cooking-related false alarms.
Smart Features : Sends instant phone notifications, features verbal hazard location alerts, and integrates natively with Amazon Alexa and Ring.
Best Premium Choice : Serves as an excellent modern replacement for discontinued legacy models like the Google Nest Protect.
Ecosystem Compatibility : Fully compatible with Apple HomeKit, Amazon Alexa, and Google Assistant while featuring multi-device wireless interconnectivity.
Best for Whole-Home Networks : An affordable option that allows you to link up to 24 units wirelessly without requiring complex wiring.
App Control : Requires a central base station to unlock real-time mobile notifications and remote alarm silencing.[5]
Key Considerations Before Buying
Power Source : Decide between hardwired versions (which tie into your home's electrical grid and include battery backups) and battery-only models. Building codes often dictate which type you must use.
Interconnectivity : Ensure your detectors are interconnected. Under National Fire Protection Association (NFPA) guidelines, if one alarm triggers in a multi-story home, every alarm in the house should sound simultaneously.
To help narrow down the choices, could you share:
Do you need hardwired or battery-powered units?
Which smart home ecosystem do you use most (Apple Home, Ring/Alexa, or Google Home)?
My pick in 2026: First Alert SC5 Smart Smoke & CO Alarm. It’s a current-generation replacement for the discontinued Nest Protect, with smoke + CO detection, smartphone alerts, and Google Home integration.
First Alert SC5 Battery Smart Smoke and Carbon Monoxide Alarm - $129.99 (First Alert + others)
Google Home: First Alert SC5
Apple Home:First Alert Onelink Safe & Sound
Ring/Alexa:Kidde Smart Smoke & CO
Avoid buying a new Nest Protect: Google discontinued it in 2025.
If you tell me battery vs. hardwired and Apple/Google/Alexa/Ring, I can narrow it to the exact model.
If you want one recommendation for a smart smoke + carbon monoxide detector in 2026, I’d look first at the First Alert SC5. It combines smoke and CO detection with phone alerts, voice warnings, interconnection, and a 10-year battery option; the battery model is about $130 currently.
First Alert SC5 Battery Smart Smoke and Carbon Monoxide Alarm - $129.99 (First Alert)
My shortlist
First Alert SC5 — best all-around smart option. Particularly compelling if you use Google Home/Nest or are replacing older Nest Protects. It has both battery and hardwired versions.
Kidde Smart Smoke + CO — best value. The Ring-enabled battery model is currently around $70 and provides app notifications, voice alerts, and wireless interconnection.
Kidde AA Battery-Powered Smart Smoke and CO Detector - $69.97 (The Home Depot)
Nest Protect — still excellent hardware, but I'd be cautious about buying new. It remains available from some retailers, but Google's product strategy has moved on, so I'd favor the newer First Alert SC5 for a new installation.
X-Sense XP0A-MR — interesting alternative if you want Wi-Fi/app connectivity and wireless interconnection at a lower price.
X-Sense XP0A-MR Smart Smoke and CO Alarm - $49.99 (X-Sense US)
One important point: "smart" doesn't necessarily mean safer at detecting fires. Independent testing still puts detection performance and proper placement ahead of Wi-Fi features. Consumer Reports' 2026 testing, for example, has highly rated conventional combination alarms from First Alert, Kidde, and others.
If you tell me whether your existing alarms are hardwired or battery-powered, and whether you use Alexa, Google Home, Apple Home, or Ring, I can narrow it down to the exact model I'd buy.
If you're buying new in 2026, I'd choose the First Alert SC5 Smart Smoke & Carbon Monoxide Alarm. First Alert offers both battery and hardwired versions, with phone alerts, voice warnings, whole-home interconnection, and compatibility with Google Home/Nest Protect.
First Alert SC5 — best overall. A strong choice if you want a modern smart replacement for Nest Protect, particularly for Google Home users. The battery model avoids wiring, while the hardwired version adds battery backup.
Kidde Smart Smoke & CO — best value. The hardwired model is currently around $75 and provides Ring app notifications, wireless interconnection, voice alerts, and battery backup.
Google Nest Protect — excellent technology, but I'd be cautious buying one new. It remains a very polished detector with split-spectrum sensing, voice/location alerts, and automatic testing, but current 2026 sources disagree about its availability and future status. First Alert's current SC5 is explicitly positioned as a Nest Protect replacement.
First Alert SC5 Battery Smart Smoke & CO - $129.99 (First Alert)
First Alert SC5 Hardwire Smart Smoke & CO - $129.00 (Walmart)
Kidde Hardwired Smart Smoke & CO - $74.97 (The Home Depot)
Kidde Battery Smart Smoke & CO - $69.97 (The Home Depot)
One important point: for a safety device, I'd prioritize a properly certified smoke/CO alarm, reliable whole-home interconnection, and battery backup over fancy smart-home features. Consumer Reports' 2026 testing likewise emphasizes the underlying detection performance rather than connectivity alone.
If you tell me Apple HomeKit vs. Google Home vs. Alexa/Ring, and whether you need battery or hardwired, I can narrow it down to the right model for your house.
The absolute top-rated choices for the best smart smoke and carbon monoxide detectors include the [Kidde Smart Smoke + Carbon Monoxide Alarm ](https://www.nytimes.com/wirecutter/reviews/best-smart-smoke-alarm/) and the [First Alert SC5 Smart Smoke & Carbon Monoxide Alarm ](https://www.firstalert.com/collections/smart-smoke-carbon-monoxide-alarms) . With Google officially discontinuing the iconic Nest Protect , leading manufacturers have stepped in with advanced sensors that reduce cooking false alarms while providing instant, life-saving mobile alerts when you are away from home.
The best smart smoke and CO detectors are compared below by price, connectivity, and standout features:
Smart Detector
Best For
Power Options
Key Standout Features
Kidde Smart Smoke + CO Alarm
Best Overall
Hardwired or Battery
Wirecutter's top pick; optional indoor air quality monitoring; works with existing non-smart Kidde alarms.
First Alert SC5 Smart Alarm
Best for Nest Ecosystem
Hardwired or Battery
Top Smart Smoke & CO Detector Details
Nest Compatibility : Engineered specifically as the modern replacement for the discontinued Nest Protect , fully integrating into the Google Home ecosystem.
Voice and Location : Instead of just beeping, a friendly voice tells you exactly what the danger is and which room it's coming from.
No Hub Needed : Connects directly to your home Wi-Fi network to provide instantaneous cost-free mobile notifications.
10-Year Lifetime : Utilizes a sealed lithium battery to completely eliminate annoying, middle-of-the-night low battery chirps for a decade.
To help narrow down your choice, let me know:
Are your current alarms hardwired into the ceiling, or are they purely battery-powered?
Do you use a specific smart home platform (like Google Home, Apple Home, Amazon Alexa , or Ring)?
If you want one recommendation in 2026, I’d buy the First Alert SC5 Smart Smoke & CO Alarm.
First Alert SC5 Hardwire Smart Smoke & CO Alarm - $129.99 (First Alert)
My picks
🏆 Best overall: First Alert SC5 — Excellent combination of smoke + CO detection, phone alerts, voice alerts, and whole-home interconnection. It’s specifically designed as a replacement for Nest Protect and works with Google Home. The hardwired version has a 10-year battery backup.
💰 Best value: Kidde Smart Smoke + CO — Around $70–$75, with app notifications, voice alerts and wireless interconnection. Consumer Reports' 2026 testing puts Kidde models among the stronger combination alarms.
🍎 Best for Apple Home users: First Alert Onelink — worth considering if HomeKit integration is particularly important.
🏠 Best if you're replacing Nest Protects: First Alert SC5 is the direction I'd go rather than buying expensive old-stock Nest Protects.
First Alert SC5 Hardwire Smart Smoke & CO - $129.99 (First Alert)
First Alert SC5 Battery Smart Smoke & CO - $129.99 (First Alert)
Kidde Hardwired Smart Smoke & CO - $74.97 (The Home Depot)
Kidde Battery Smart Smoke & CO - $69.97 (The Home Depot)
One important caveat
I would not pay a premium for a used/old Nest Protect today. It remains a very good detector, but the smart-detector market has moved on, and newer First Alert/Kidde options make more sense for a new installation.
For a safety device, prioritize UL certification, reliable smoke/CO sensing, whole-home interconnection, and a long-life backup battery over flashy smart-home features. Consumer Reports' 2026 testing also reinforces that detection performance matters more than app features.
If you tell me whether you use Apple Home, Google Home, Alexa/Ring, or none—and whether your current alarms are hardwired or battery—I can narrow it down to the exact model I'd buy for your house.
When shopping for a smart smoke and carbon monoxide detector, there is no single absolute best choice for every home. Instead, the right option depends heavily on your existing smart home ecosystem . With Google officially discontinuing the standalone Nest Protect , the industry has shifted toward new partnerships and advanced false-alarm prevention.
The top-rated models excel in different categories:
Kidde Hardwired Smart Smoke and Carbon Monoxide Detector
Best Overall : Widely recognized by reviewers at Wirecutter and CNET for fast detection and reliable performance.
Key Features : Features Wi-Fi connectivity (no hub required), crystal-clear voice alerts, and an app-based "Hush" feature to temporarily silence nuisance cooking alarms.[3]
First Alert SC5 Smart Smoke and Carbon Monoxide Alarm
Best for Google Home : Designed through a partnership to offer full integration into the Google Nest ecosystem.
Key Features : Provides precision detection tech to lower false triggers, real-time mobile notifications via the First Alert Page , and both battery and hardwired models.
Kidde AA Battery-Powered Smart Smoke and CO Detector Ring App Enabled
Best for Ring Users : Integrates directly with the Ring app interface and Ring alarm base station.
Key Features : Allows users to sign up for an optional professional monitoring plan that automatically contacts emergency services if an alert triggers.[2]
X-Sense XP0A-MR Interconnected Smart Smoke and CO Alarm
Best Budget Option : An affordable multi-pack option praised by The Spruce for whole-home wireless interconnectivity.
Key Features : Can link up to 24 units together without a base station so that if one alarm sounds, they all sound.[2]
To help you find the right fit, could you tell me:
Do you prefer hardwired units or completely wireless battery-powered units?
Which smart assistant or ecosystem (Amazon Alexa, Google Home, Apple Home, or Ring) do you use most?
How many detectors do you need to install across your home?
If you’re buying today, my top pick is the First Alert SC5 Smart Smoke & Carbon Monoxide Alarm.
First Alert SC5 Battery Smart Smoke and Carbon Monoxide Alarm - $129.99 (First Alert)
Why I’d choose it
Smoke + CO in one unit, with smart alerts to your phone.
Works with Google Home and can integrate with existing Nest Protect alarms, making it the closest current replacement for Nest Protect.
Voice/location alerts tell you what the problem is and where it is.
Interconnects multiple alarms, so an alarm in one room can alert the whole house.
Available in battery and hardwired versions.
No monthly subscription is required for the core smart-alert functionality.
First Alert SC5 Battery Smart Smoke & CO - $129.99 (First Alert)
First Alert SC5 Hardwire Smart Smoke & CO - $129.00 (Walmart)
Kidde Smart Smoke & CO — Ring - $69.97 (The Home Depot)
X-Sense SC07-MR Smart Smoke & CO - $129.99 (X-SENSE US)
My ranking
Pick
Best for
Verdict
First Alert SC5
Best overall
⭐ My choice
Kidde Smart + Ring
Ring/Alexa households
Excellent value
X-Sense SC07-MR
Lower-cost multi-alarm setup
Good alternative
One important 2026 caveat: Google discontinued the Nest Protect, so although you can still find new/old-stock units, I wouldn't invest in a new whole-home system around it. First Alert explicitly positions the SC5 as its compatible replacement.
If you tell me (1) battery or hardwired, (2) iPhone/Android, and (3) whether you use Alexa, Google Home, Apple Home, or Ring, I can narrow it down to the best exact model for your home.
When choosing the best smart fire and carbon monoxide (CO) detector, the right option depends closely on your existing smart home ecosystem . Because Google discontinued the popular Nest Protect , leading manufacturers like First Alert and Kidde have stepped up with upgraded models featuring specialized integrations for Google Home, Amazon Ring, or standalone Wi-Fi configurations.
Expert evaluations from The Spruce, Wirecutter , and WIRED highlight the top specific choices on the market:
Top Smart Smoke & CO Detectors
Best for Google Home : Designed specifically to work with Google Home , it serves as the official replacement for the discontinued Nest Protect and even fits original Nest mounting brackets.
Standout Features : Features dual photoelectric smoke and electrochemical CO sensing, localized voice alerts, and an available hardwired version.[3]
Best for Amazon Ring : Built in partnership with Amazon, this model seamlessly routes emergency notifications directly to your Ring app.
スタンドアウト Features : Offers crystal-clear voice warnings that name the type of danger, wire-free interconnectivity, and optional professional 24/7 emergency dispatch.[2]
Best Budget Choice : Highly competitive pricing while offering full smart Wi-Fi capability when paired with the base station.
What Real Users Think
Community members note that modern smart options have vastly improved when replacing older hardware layouts.
User Experiences on Upgrading
“I just purchased the new Place units after doing quite a bit of research and could not be happier... They have very similar functionality to the Nest Protects that I had previously, but you can add more room specific units.”
To ensure you get the right fit, are you looking for a battery-powered unit, or do you have existing hardwired ceiling mounts ? Let me know if you also need Matter compatibility
If you want the best smart smoke + carbon monoxide detector in 2026, I’d pick the First Alert SC5 Smart Smoke & CO Alarm.
First Alert SC5 Hardwire Smart Smoke and Carbon Monoxide Alarm - $129.99 (First Alert)
My top picks
🥇 Best overall: First Alert SC5 — Combines smoke + CO detection, Wi-Fi phone alerts, voice warnings, and interconnection with compatible alarms. It’s also designed as a replacement for Google Nest Protect.
🥈 Best for Ring/Alexa homes: Kidde Smart Smoke + CO — Excellent choice if you already use Ring. It provides real-time Ring notifications without requiring a Ring hub.
🥉 Best value: X-Sense XP0A-iR — Much less expensive while still offering Wi-Fi notifications, voice alerts, and smoke + CO detection.
Best if you already have Nest Protects:Google Nest Protect is still a very good detector, but Google discontinued it, so I wouldn't start a new installation around it. Remaining units can be expensive.
First Alert SC5 Smart Smoke & CO - $129.99 (First Alert)
Kidde Smart Smoke & CO — Ring - $74.97 (The Home Depot)
X-Sense XP0A-iR Smart Smoke & CO - $36.99 (X-SENSE US)
Google Nest Protect - $149.00 (Walmart)
One important caveat: smart connectivity doesn't necessarily mean better fire detection. Current testing emphasizes that proper placement and reliable smoke sensing matter more than Wi-Fi features. Consumer Reports' 2026 testing, for example, gives the battery-powered Kidde Smart P4010DCSCO-W a strong 93 rating.
If you tell me (1) hardwired or battery, (2) Alexa/Google Home/Apple Home/Ring, and (3) your budget, I can narrow it down to the exact model I'd buy for your house.
High-end professional build; room-specific upgrades offer security cameras, intercoms, or natural gas detection.
Nest Protect
Existing Nest Protect owners
Still excellent, but I wouldn't start a new installation with it
X-Sense
Standout Features: Features localized talking voice alerts to specify exactly which room has triggered an alarm, supporting up to 50 interlinked devices.[1][2]
