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Smoke detectors are a lot like income taxes: We need to deal with them once a year, not a whole lot of people understand them, and issues with either can be particularly, well, alarming. Simple yet essential heroes of home safety and security, smoke detectors tend to be forgotten until they go off (a good thing) or fail to function in an emergency (a potential tragedy).
The National Fire Protection Association recommends at least one smoke detector for each floor of a home, as well as one in every bedroom. It’s important to become familiar with the types of detectors, how they operate, and some of the finer points of fire alarm technology. Even if you don’t think you’re in the market for a new model right now, you very well might be after reading this article.
As the first line of defense against a house fire—and, in many cases, a guard against carbon monoxide (CO) as well—smoke detectors protect those in your home 24/7. I personally did hands-on tests with 12 models to help you choose one that you can trust to protect yourself, your loved ones, and your home. The following models made our list of top picks.
- BEST OVERALL: X-Sense SC07 Wireless Smoke & Carbon Monoxide Alarm
- BEST BANG FOR THE BUCK: Kidde i9050 Battery-Operated Smoke Alarm
- BEST IN TECH: Google S3003LWES Nest Protect Smoke and CO Detector
- BEST INTERCONNECTED: Kidde RF-SM-DC Wireless Interconnect Smoke Alarm
- BEST VOICE ALARM: Kidde KN-COSM-BA Smoke & Carbon Monoxide Alarm
- HONORABLE MENTION: First Alert SCO5CN Smoke & Carbon Monoxide Alarm
- ALSO CONSIDER: First Alert Z-Wave Smoke & Carbon Monoxide Alarm
How We Tested the Best Smoke Detectors
While pressing the “test” button is a perfectly fine way for folks to perform once-a-month testing of a smoke detector, a simple button-test cannot tell the whole story of how well a unit will perform. A lot more went into our testing and, as someone who’s spent nearly a decade working with commercial fire alarms, this assignment was right in my wheelhouse.
I installed each of these devices one by one, according to the directions, to determine how easy they were to set up. I also tested each device by spraying two puffs of canned synthetic smoke—the same type I used when testing fire alarms professionally. I timed each to get a solid sense of how long activation took and then compared the results.
Our Top Picks
These top picks include photoelectric, ionization, and dual-sensor smoke detectors to suit a variety of different needs. All are quality models currently on the market that I tested personally in the hope that my fair and honest opinions will help streamline your search for the best smoke detector.
Note: All of the following products feature battery operation, making them very easy to install. They’re also all Underwriters Laboratories (UL)–listed for safety.
Best Overall
X-Sense SC07 Wireless Smoke & Carbon Monoxide Alarm
Pros
- Features a smoke sensor and a carbon monoxide sensor for double the protection against these household hazards
- Large digital display shows the carbon monoxide parts per million to provide a quick reference
- Sleek, modern design that will fit in with tech-inspired home and apartments
Cons
- It has an activation switch that has been an issue on previous X-Sense models
Product Specs
- Type: Photoelectric (smoke) and electrochemical (CO)
- Interconnect: No
- CO detection: Yes
The X-Sense SC07 combo alarm is a two-way player that would benefit many homeowners. This model features a photoelectric sensor that detects smoke particles and an electrochemical sensor that detects the presence of carbon monoxide. It also has a digital display that shows the carbon monoxide parts per million (ppm) in the air as well as the battery’s status. This also lends it a sleek design that will easily fit in with modern spaces.
The real star of the show is the display, which clearly indicates the level of carbon monoxide in the air when it’s more than 30 ppm (registers as 0 under that amount). While a sensor capable of reading lower levels would be better, I still find it reassuring. Also, this device triggered within 10 seconds during testing, though it did take a while to silence.
I’m not, however, a big fan of this model’s activation switch. While it worked perfectly on the model I tested, I have broken that switch on previously tested X-Sense models, so I would still caution users to be very gentle with it. Otherwise, I felt this was the best overall smoke detector. Plus, an interconnected version is available.
Get the X-Sense smoke detector at X-Sense, Amazon (interconnected), or Walmart.
Best Bang For The Buck
Kidde i9050 Battery-Operated Smoke Alarm
Pros
- Affordable price point may allow more users to purchase multiples and protect their homes right away
- Loud alarm is audible throughout the home, ensuring everyone knows when there is an alert
- Activated slowly but silenced immediately, making it one of the easiest models to silence
Cons
- Roughly 10 seconds slower to alert than other devices
Product Specs
- Type: Ionization
- Interconnect: No
- CO detection: No
A hardwired, Wi-Fi, or interconnected fire alarm system can be expensive, but thanks to the affordable price of the Kidde i9050, users can equip the entire home for smoke detection without burning out the bank account. Though hardly a high-tech option, this basic ionization-style model, which runs on a 9-volt battery, is a reliable option for smoke detection.
Considering the budget-friendly price, I was skeptical about how well this alarm would perform during testing. While it did perform roughly 10 seconds slower than other devices, it alarmed within 25 seconds, and the siren was loud. Also, I was able to silence this alarm much faster than devices that cost four times the price. In my opinion, it truly offers the best value for dollar of any detector on the list, though it doesn’t offer many special features.
Get the Kidde i9050 smoke alarm at Amazon or Walmart.
Best in Tech
Google S3003LWES Nest Protect Smoke and CO Detector
Pros
- Crystal-clear voice instructions that describe the hazard and where it’s located
- Reports to a phone app so users will receive alerts if there is an activation
- Better looking than other detectors with a modern look similar to a speaker or audio device
Cons
- A bit tricky to connect the device to the app at first, so it takes some patience
- Users will want to remember to keep the app updated; avoid skipping any update alerts
Product Specs
- Type: Split-sensor, which acts as both photoelectric and ionization
- Interconnect: Yes
- CO detection: Yes
Equipped with the latest technology available today, the Google S3003LWES Nest Protect smoke and carbon monoxide alarm ties into existing hardwired systems and features Wi-Fi communication. Users can program the alarm so it will indicate the location in the home where an activation is taking place through both the Nest app and the built-in speaker. It uses dual-sensor technology to detect both smoldering burns and flaming fires.
In my test, I found the Nest Protect’s voice activation to be clear and the alarm to be fast. I also liked the appearance of this device and appreciated that the baseplate offers quite a bit of rotational adjustment to ensure that it is straight when installed. Connecting the detector to the Nest app took a couple of tries, though.
There’s a larger caveat regarding this product and similar models that work with smart-home systems: Their compatibility with those systems depends on app updates, which means users must remember to keep up-to-date on apps. If the app is an old version, the detectors might fail to communicate with a smartphone or central monitoring service.
Get the Google smoke detector at Amazon, The Home Depot, or Best Buy.
Best Interconnected
Kidde RF-SM-DC Wireless Interconnect Smoke Alarm
Pros
- Very fast activation ensures that users will know about any dangerous conditions as soon as possible
- Easy to hush or silence, making accidental activation less of a headache
- Wireless interconnect without an app or hub for easy and reliable setup
Cons
- Took a few tries to lock it onto the base due to a somewhat nonintuitive design or any alignment indicators
Product Specs
- Type: Ion
- Interconnect: Yes
- CO detection: Yes
Older homes without pre-existing fire alarm wiring may be best served by the Kidde RF-SM-DC wireless smoke detector with interconnection. This model can provide interconnecting coverage without expensive wiring or smart-home apps. These simple battery-operated units use three AA batteries to communicate with each other through radiofrequency, rather than Wi-Fi.
When one detector activates, it signals the others through radio waves, causing a fast chain reaction of alarms. The downside is that fluctuations outside the temperature range of 40 to 100 degrees Fahrenheit can cause false alarms and lead to premature battery failure. However, with a few of these units, even such areas as detached garages and sheds can connect for protection.
Though I only tested one device, these smoke detectors operate in a very simple way that’s unlikely to fail: They feature a set of dip switches on the back, and all the user must do is ensure the switches on all the devices match to get them all to activate at once. In my testing, I found that the device activated quickly and was easy to silence. Locking it to the base took a few tries, unfortunately, because it wasn’t especially intuitive.
Get the Kidde RF-SM-DC smoke detector at Amazon or The Home Depot.
Best Voice Alarm
Kidde KN-COSM-BA Smoke & Carbon Monoxide Alarm
Pros
- Handy alarm-light guide on the back helps users identify different conditions
- Clear voice directions alert users to the hazard at hand, whether it’s smoke or carbon monoxide
- Well-designed ratcheting base allows for flexible positioning for best appearances
Cons
- Didn’t immediately silence during testing, so it might be hassle for accidental activations
Product Specs
- Type: Ionization
- Interconnect: No
- CO detection: Yes
When a traditional smoke detector siren starts, panic and confusion can set in rather quickly. To help alleviate some of the stress, Kidde’s KN-COSM-BA battery-powered combination alarm sounds clear, easy-to-understand alerts for residents. The detector will provide a clear indication of the hazard at hand by repeating one of three warnings: “fire,” “warning: carbon monoxide,” or “low battery.”
This combination detector alerts to both smoke and carbon monoxide. It also has an easily accessed battery compartment on the front for quick battery changes. And though this unit doesn’t interconnect with other devices, it sounds an 85-decibel alarm that should be loud enough to alert everyone in the house.
During testing, I found this Kidde model to perform very well. The front-access battery compartment is simple, and the back of the unit features a handy guide to determine which codes the flashing lights might be signaling. I also considered the ratcheting base to be well designed, as it allowed for flexible positioning even after securing the base. My only complaint was that it took four tries to silence the alarm.
Get the Kidde KN-COSM-BA smoke detector at Amazon or Walmart.
Honorable Mention
First Alert SCO5CN Smoke & Carbon Monoxide Alarm
Pros
- Very loud siren ensures that everyone in the home can hear the activation
- Easy to install using the base plate and included hardware
- Combination smoke and CO sensors alert to both hazards for double the protection
Cons
- Would not silence, so it’s not a great choice for a space like a kitchen
Product Specs
- Type: Combination photoelectric smoke and electrochemical CO
- Interconnect: No
- CO detection: Yes
Anyone on the hunt for an affordable combination smoke and carbon monoxide detector may want to check out the SCO5CN combination from First Alert. This device features an electrochemical carbon monoxide detector as well as a photoelectric smoke sensor, activating an 85-decibel alarm when either sensor triggers.
One of the best aspects of testing the First Alert SCO5CN was its simple, fast setup. While it does suffer from the same goofy pull-out battery drawer as other First Alerts, mounting it to the ceiling was a breeze. Also, the siren was loud and clear when alerting under smoke conditions. Again, as I found with other First Alerts, the unit refused to silence, so it’s not a great choice for kitchens or workshops.
Get the First Alert SCO5CN smoke detector at Amazon.
Also Consider
First Alert Z-Wave Smoke & Carbon Monoxide Alarm
Pros
- Easy to install using the base plate and included hardware
- Loud enough that residents will be alerted throughout the home
- Fastest activation in test, ensuring that it will begin alarming in dangerous conditions
Cons
- Requires Ring hub for full use of features and connectivity
Product Specs
- Type: Combination photoelectric smoke and electrochemical CO
- Interconnect: Yes, via Ring hub
- CO detection: Yes
First Alert’s Z-Wave smoke detector and carbon monoxide alarm is worth considering by those who want to set up their own interconnected system that they can access from a phone and other devices. This combination smoke detector interfaces with the Ring Alarm hub and app, offering users real-time alerts wherever they have internet service. This unit features a photoelectric smoke sensor and an electrochemical carbon monoxide detector to alert under a variety of conditions.
Like most First Alert devices, the Z-Wave alarm was very easy to install. The audible alarm was very loud, and it activated faster than the time it took to reach for my stopwatch. The only issues I experienced when testing were its refusal to silence it (a common problem with First Alert) and, obviously, if you don’t have a hub, this will only work as a basic combination detector.
Get the First Alert Z-Wave smoke detector at Amazon or Lowe’s.
ALSO TESTED: Ring Alarm Smoke & CO Listener
I really liked the idea of the Ring Alarm Smoke & CO Listener, as it basically functions as a bridge between a nonmonitored system and a fully connected self-monitored system. However, there are too many shortcomings for me to recommend this device:
- It only works with chirping detectors, so it won’t alert users to voice alarms.
- It requires a Ring alarm system base, which isn’t really a drawback for those already invested, but it is a hurdle for anyone who isn’t.
- It doesn’t tell the user anything about the condition of their system, such as the battery level and status of the individual devices.
- If the system isn’t interconnected, individual device activation might not activate the Ring listener.
It worked OK during testing, but there are too many drawbacks for this device to be practical.
ALSO TESTED: Kidde P4010LDCS-W Interconnected Battery Smoke Alarm
The Kidde P4010LDCS-W smoke alarm was impossible to set up. It is designed to link to the Kidde app via Bluetooth but would not register on any of the devices that I tried, which included two Android phones and an iPad. I reset it several times using the “Quick Start Guide” and even tried using the QR code through the app (which did not cooperate at all).
I’ve previously found that smart tech is not Kidde’s strong suit. Although I’ve trusted the brand for almost 20 years, only a few of the brand’s smart-enabled devices are ready for practical use.
ALSO TESTED: First Alert Hardwired LED Strobe Light Smoke Alarm
First Alert’s strobe light smoke alarm was a big disappointment, especially for the cost. My test model didn’t function like it was supposed to. During testing, I could not get the strobe to light. I even checked the directions to make sure that it wasn’t something that I needed to activate or that it only worked during certain conditions, but that wasn’t the case. This is a device that is supposed to alert hearing-impaired folks to a dangerous condition, and the strobe should never fail.
Jump to Our Top Picks
What to Consider When Choosing a Smoke Detector
Even if tested annually, a smoke detector has an operational lifespan of only 10 years. A model older than that should be replaced, regardless of its working condition. To help make an informed decision, learn about the following key features that pop up when considering the wide range of models currently on the market
Hardwired vs. Battery Operated
Battery-operated models, which tend to cost less, are usually stand-alone detectors. This means an activated smoke detector cannot alarm a monitoring system or other sensors in the home; only the detector in the smoky area will sound an alarm. The exception would be battery-operated models that are part of a home security system.
Hardwired smoke detectors install directly to the electrical system of the home. When one sounds an alarm, typically all of the detectors follow suit. While this may make it harder to pinpoint the unit that actually detected the issue, it alerts everyone in the house to danger, which is undeniably a considerable asset.
Most residential hardwired detectors now use battery backups, so even if the power goes out, the home will still have some fire safety protection—and that’s the best of both worlds. In commercial applications, things work a bit differently, in that the fire alarm panel will rely on the batteries to keep the alarm system live until the generators kick on or the power comes back.
Interconnectivity
Briefly touched upon above, interconnectivity refers to smoke detectors’ ability to “talk” to each other, alerting the entire system to an issue. For example, if there were an electrical fire within the car in an attached garage, the entire system throughout the house would activate immediately.
Fires can double in size every 60 seconds, so if residents were sleeping on the other side of the house, they might not hear a stand-alone detector activate in the garage. Interconnected detectors will make them aware of the issue, potentially before it’s too late.
Carbon Monoxide
In a similar circumstance, a car left running in the garage can produce fatal levels of carbon monoxide, which could prove particularly dangerous to folks sleeping in a bedroom above. Smoke detectors with carbon monoxide sensors add another level of safety. While all homes should have carbon monoxide detectors, homes with gas or oil heat and hot water are particularly vulnerable.
Monitoring
Interconnected detectors are often part of a monitored home security system. The great benefit to these systems is they can alert the local fire department, even if no one is at home to make the emergency call. A carbon monoxide issue could render those inside unable to call the fire department, so the monitoring company can make that call, possibly saving lives.
UL Listing
Quality smoke detectors are UL listed. This certification ensures that the detectors meet UL’s stringent testing requirements. Given the importance of purchasing the best smoke detector system that a household can afford, it’s not worth the risk to install anything that isn’t UL listed.
Smart Features
For those interested in the latest fire safety technology, some detectors do boast smart features. Many of these detectors not only communicate with an overseeing alarm system but also with users’ phones through Wi-Fi. Some models even allow users to employ any TV remote to mute an activated detector.
Types of Smoke Detectors
There are three main types of smoke detectors: photoelectric, ionization, and dual sensor. While they all do the same job, they go about it differently.
Photoelectric
The chamber of a photoelectric smoke detector contains an LED light, which shoots a beam across the chamber, and a sensor that sits approximately 90 degrees from the LED. Under normal conditions, the sensor can’t “see” the LED beam, but when smoke enters the chamber, the light reflects off smoke particulates and the sensor detects the beam.
The instant the sensor detects the beam, the alarm activates. Photoelectric smoke detectors are most effective at detecting smoldering burns—barely burning fires that can, frighteningly, smolder for days before becoming a bigger issue.
Ionization
Though these detectors employ radioactive materials, alpha rays, and other seemingly sci-fi technology, they operate on a fairly simple premise: A chamber fills with tiny particles called ions, held in place by electrical charges. A sensor in the chamber knows how many ions are contained within.
When smoke enters the chamber, it removes some of the ions, affecting the sensor’s count and sounding the alarm. Ionization smoke detectors are most effective against fires that are actively flaming.
Dual Sensor
Just as the category name suggests, these detectors use both types of sensors. There’s no winner in a race against photoelectric and ionization detectors, and they each have their own strengths. The use of both sensor types means faster detection of threats across the range of different materials that could be burning.
FAQs
Now that you know a bit more about the best smoke detectors, some questions may still pop up. Here are answers to some of the most frequently asked questions, so check below for the information that will clarify your queries.
The U.S. Fire Administration states that you should test your smoke detectors monthly and replace the batteries at least once a year.
The National Fire Protection Association recommends that homes should have smoke detectors installed in every bedroom, a common area outside the sleeping area, and on every level (including the basement and attic).
Smart smoke detectors provide a bit of extra awareness, particularly if no one is at home when the issue occurs. However, they’re not necessarily better. Some would suggest that having a hardwired system tied into a central monitoring service is the best option.
Most smoke detectors feature dual-purpose test and “hush” buttons that will allow the user to test their detector’s functionality but also stop it from sounding an alarm. However, if your smoke detector is simply beeping, it probably just needs a battery change.
Meet the Tester
Tom Scalisi is a full-time DIY and construction writer for many of the largest websites in the industry, including BobVila.com, This Old House, Family Handyman, and Forbes. He spent years in the fire safety industry, both installing and testing commercial fire alarm and suppression systems.
