Which is better kidde or first alert

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Smoke detectors don't seem to get the same attention as home security systems, and for something so important to home and personal safety, this can be a costly mistake. Having smoke alarms can lower the risk of death in a house fire by 55%, according to the National Fire Protection Association (NFPA).

Due to the amount of synthetic material in modern furniture and buildings, home fires can spread fast. Thirty years ago, you had about 17 minutes to escape a home fire; today, it's about 2 minutes, according to Underwriters Laboratories, which conducts some of the leading fire safety tests in the US. A reliable and effective smoke detector can alert you quickly to get you and your family to safety. 

I have years of experience relocating and installing hardwired smoke detectors as a residential carpenter and leaned on that expertise when testing six units for this guide. (I go through my full testing methodology here.) I also consulted Patrick Andler, a fire investigator with 38 years of experience and a board member of the Arizona Burn Foundation, and Nick Yahoodain, a home remodeler with 11 years of experience at Advanced Builders & Contractors, on how to install smoke detectors, how to use them effectively, and more.

The best smoke detectors in 2022

Best smoke detector overall: X-Sense SC01, $29.99 from Amazon
The X-Sense SC01 features a 10-year lithium battery, carbon monoxide detector, and a color-changing LED to let you know its current status.

Best smart smoke detector: Nest Protect, $119 from The Home Depot
The Nest Protect features both a carbon monoxide and split-spectrum smoke detector that detects both fast and slow-burning fires and delivers clear verbal instructions to explain why its sensor was triggered and what you should do next.

Best smoke detector for smoke only: X-Sense XS03-WX Wi-Fi Smoke Alarm, $29.99 from Amazon
If you already have a standalone carbon monoxide detector, we recommend the X-Sense XS03-WX Wi-Fi Smoke Alarm for a dependable smoke detector that can be controlled with a convenient mobile app.

Best dual-sensor smoke detector: First Alert SA320, $19.79 from Amazon
The First Alert SA320 is an affordable and effective smoke alarm with both photosensitive and ionization sensors, which can cause it to be too sensitive at times.

Best interconnected smoke detector: X-Sense Wireless Interconnected, $23.99 from Amazon
The X-Sense Wireless Interconnected comes as a set of three, six, or 12 separate smoke detectors with a range of more than 820 feet each, so they can cover small and large spaces safely.

Best ionization smoke detector: Kidde RF-SM-DC, $38.35 from Amazon
Wire-free (radio) interconnectivity, AA battery power, and a hush button make this ionization detector an easy and trusty addition to your fire detection network.

Best smoke detector-carbon monoxide detector combo: First Alert PRC710 Combination Smoke and Carbon Monoxide Detector, $34.98 from Lowe's
The multifunctional First Alert PRC710 alerts you to the presence of both smoke and carbon monoxide and boasts an ultra-thin profile that will blend into your ceiling.

Best smoke detector overall

Keep in mind: With a quality product, your lifetime cost can be significantly lower than purchasing cheaper products that don't last.

The X-Sense SC01 features a 10-year lithium battery, carbon monoxide detector, and a color-changing LED to let you know its current status.

Pros: Digital battery level display, doubles as carbon monoxide detector 

Cons: Lacks ionization sensor 

The X-Sense SC01 responded well in my testing and activated its alarm within two sprays of the aerosol. It had a loud alarm that was clearly heard from across the 2,700-square-foot house I tested it in, and its red LED flashed continuously while the alarm was sounding. The alarm and light shut off simultaneously when the sensor no longer detected any aerosol. 

The X-Sense SC01 lacks an ionization sensor and uses only a photoelectric sensor to detect smoke. This makes it marginally less sensitive to flash fires but also cuts down on the chances of it being set off by nuisance alarms, or false alarms caused by cooking smoke or steamy showers. Its screen displays the real-time amount of carbon monoxide in the air, the status of the unit during a test, and a battery level icon.

Installing the X-Sense SC01 was simple, and with a power drill and pencil, I was able to attach it to the ceiling in about two minutes. The anchors are white, so they blended in with the ceiling and also came in a resealable plastic baggie, which was convenient.

Overall, the value of the 10-year battery, the carbon monoxide detector, and digital readout make it the best option I tested. The detector also comes highly recommended by our fire investigator expert.

Best smart smoke detector

Keep in mind: With a quality product, your lifetime cost can be significantly lower than purchasing cheaper products that don't last.

The Nest Protect features both a carbon monoxide and split-spectrum smoke detector that detects both fast and slow-burning fires and delivers clear verbal instructions to explain why its sensor was triggered and what you should do next.

Pros: Spoken instructions, phone notifications

Cons: Lacks ionization sensor, may not be ideal for those not technically savvy, requires three AA backup batteries

The color-changing LED, along with the verbal commands and smartphone notifications, made the Nest Protect fun to test out and operate. My first aerosol test activated its "heads-up" function, which issued a verbal warning that it detected a small amount of smoke. This would be a convenient feature if the smoke was due to burning toast or another non-emergency — especially for anyone who might get overwhelmed by loud noises. By giving you the chance to resolve the problem before the smoke levels rise, you can prevent the unit from going into full-blown alarm mode. My second aerosol spray was enough for the Nest Protect to assume there was an actual fire, and it sounded its alarm immediately. 

The Nest Protect allows you to easily silence the unit in the event of a nuisance alarm with the large and easy-to-press test/silence button. You can even silence the alarm from your smartphone, although it doesn't allow for this if the smoke is too heavy.

The Nest Protect is a hardwired unit, so installation was a bit more elaborate than the other smoke detectors I tested. This will involve working with and reconnecting electrical wiring, so if you're uncomfortable around that type of thing, you may want to hire a professional. It took me about 15 minutes to remove the previous unit and connect this one. The instructions walked me through every step of the process, and the included hardware was effective and easy to use. It also took me about 15 minutes to connect the Nest Protect to my home's Wi-Fi network due to connection issues. 

If your home Wi-Fi goes down like in the event of a power outage, the Nest Protect will continue to work just fine — you just won't get any notifications on your phone. The three AA batteries will ensure the Nest Protect continues to work during a power outage.

Best smoke detector for smoke only

Keep in mind: With a quality product, your lifetime cost can be significantly lower than purchasing cheaper products that don't last.

If you already have a standalone carbon monoxide detector, we recommend the X-Sense XS03-WX Wi-Fi Smoke Alarm for a dependable smoke detector that can be controlled with a convenient mobile app.

Pros: Compact size, Mobile app compatibility, Easy to interconnect additional units

Cons: Lacks a carbon monoxide detector

The XS03-WX Wi-Fi Smoke Alarm uses a photoelectric sensor that works with the airflow design of the casing to better detect a variety of fire types. To minimize nuisance alerts, the sensor also analyzes smoke three times before activating the alarm.

The smoke detector's most notable feature is its connectivity to the X-Sense Home Security mobile app, which is free to use after a one-time purchase. You can both test and silence the detector from your phone, eliminating the need to reach up and perform those tasks manually. The app also provides real-time alerts and notifications when danger is detected and allows you to easily interconnect several smoke detectors at once. You can connect up to 24 X-Sense XSO3-WX in the same home, and by giving each one a unique name, you'll know which one has been triggered.

Although I wasn't able to test the X-Sense XSO3-WX, I have hands-on experience with several X-Sense models, including the discontinued X-Sense SD01, our previous winner in this category. I have had great experiences with both functionality and overall build quality of the units. The XSO3-WX offers the same simple installation process as its siblings — use a pair of screws to mount in place or adhesive tape if you'd prefer something less invasive. 

The detector is also designed to constantly auto-check itself to make sure it's always functioning properly. Keep in mind that the X-Sense XSO3-WX doesn't use a 10-year battery, so you'll need to replace its 3V battery every year. 

Best dual-sensor smoke detector

Keep in mind: With a quality product, your lifetime cost can be significantly lower than purchasing cheaper products that don't last.

The First Alert SA320 is an affordable and effective smoke alarm with both photosensitive and ionization sensors, which can cause it to be too sensitive at times.

Pros: Has both photosensitive and ionization sensors, has safety features suitable for landlords 

Cons: Very sensitive, batteries must be replaced regularly

The First Alert SA320 features both photosensitive and ionization sensors, which is likely the reason why it was the only unit that activated its alarm after a single aerosol spray test. 

Although this high sensitivity sounds good on paper, it can also be the cause of frequent nuisance alarms. These alarms, combined with the removable AA batteries, greatly increase the odds that someone will remove the batteries or the alarm itself. The NFPA reported that between 2009-2013, 21% percent of deaths in home fires occurred when smoke detectors were "present but did not operate." It's important to keep this in mind if you're planning to get this unit.

I didn't experience any issues installing the First Alert SA320. It uses red wall anchors, which aren't ideal if you want to move the unit to a different location in the room. It also has optional locking features to discourage unauthorized battery or alarm removal. This is a good feature for landlords or anyone else placing the unit who won't be there to monitor it.

The First Alert SA320's design makes it feel more functional and less clunky. It does lack the polished appeal of the X-Sense models, though it shouldn't be a big factor compared with safety and effectiveness. Andler describes this as "a standard smoke detector at a good cost."

Best interconnected smoke detector

Keep in mind: With a quality product, your lifetime cost can be significantly lower than purchasing cheaper products that don't last.

The X-Sense Wireless Interconnected comes as a set of three, six, or 12 separate smoke detectors with a range of more than 820 feet each, so they can cover small and large spaces safely.

Pros: Small size is easy to install, easy to find silence button in the dark, covers large areas

Cons: Does not have a built-in battery 

Even though the X-Sense Wireless Interconnected smoke detectors are smaller and lighter than typical ones, they still meet UL 217 standards. They also beeped at the same 85-db level as every other model tested. Their red alert lights were easy to see, and because of their side-mounted position, they reflected off the ceiling to increase visibility.  

Because they are interconnected, all the units will sound even if only one detects smoke, so you'll be notified regardless of where you are in your home when a fire breaks out. They performed effectively in every test I did and were all relatively sensitive, responding within two aerosol sprays. Since the silence button is also the alert light, it was easy to quickly find the button to silence the unit, even in low light. 

Each unit was interconnected right out of the box, so there was no additional setup necessary. You can add up to 24 units to the network, but every new set will need to be manually connected to the rest. This process seems pretty straightforward though, and X-Sense's instructions are clear.

Installation of the six-pack took longer than other smoke detectors I tested because there were more units to install. Their small size only required two anchor holes per unit, as opposed to the three that the other units I tested needed. This not only made them easier to install but also reduced the amount of damage to the ceiling and walls. Each of the units easily clicked onto its mounting bracket, and they were the simplest to install out of all smoke detectors I tested. Like all X-Sense models, their smooth finish gave them a nice, high-quality look. 

Best ionization smoke detector

Keep in mind: With a quality product, your lifetime cost can be significantly lower than purchasing cheaper products that don't last.

An ionization sensor, wire-free (radio) interconnectivity, AA battery power, and a hush button make the Kidde RF-SM-DC an easy and trusty addition to your fire detection network.

Pros: Detects flash/flaming fires faster than photoelectric models, smart-touch nuisance-alarm silencer

Cons: Not sufficient at detecting smoldering fires (does not include photoelectric sensor), prone to nuisance alarms, on the large side

Because it's best to separate your various detectors in order to monitor a wider area and range of fires, an ionization detector like the Kidde RF-SM-DC pairs well with our top recommendation, a photoelectric detector.

Ionization detectors use a light radioactive charge to create an electrical current, which, when broken, sounds the alarm. Models like this are best suited to detect the invisible particles of flash and flaming fires, while photoelectric fires are quicker to react to particles emitted by smoldering fires. By placing ionization detectors further from kitchens and bathrooms and photoelectric detectors nearer to kitchens and bathrooms, you'll create a much more effective network.

The ability to connect up to 24 Kidde devices using neither WiFi nor hard-wired electricity makes this battery-powered device dependable, especially if you have issues with your electricity or internet service provider.

The RF-SM-DC requires no user programming and is ready to go straight out of the box. It runs on three AA batteries and comes with all of the basic bells and whistles, including a low-battery chirp alarm, a test function, and a smart-touch button to silence nuisance alarms (common with ionization detectors). Just be sure to test the batteries every six months or so.

Best smoke detector-carbon monoxide detector combo

Keep in mind: With a quality product, your lifetime cost can be significantly lower than purchasing cheaper products that don't last.

The multifunctional First Alert PRC710 alerts you to the presence of both smoke and carbon monoxide and boasts an ultra-thin profile that will blend into your ceiling.

Pros: Dual function does not compromise effectiveness, low-profile shape, long-lasting battery

Cons: Lacks ionization sensor, does not provide voice alerts

Another well-regarded First Alert model, the First Alert PRC710 uses a photoelectric sensor to quickly and effectively detect smoldering fires, which should cut down on frustrating false alarms. It also uses different beeps for each type of alert — three beeps for smoke, four beeps for carbon monoxide — allowing you to know exactly what the problem is upon activation. Although these are useful, I wish it used a voice-alarm to explain the alerts. 

The First Alert PRC710 performed well during my testing on all three days and consistently activated its smoke alarm after two sprays from my aerosol canister. Installation was a breeze as well; it took just a couple of minutes to insert the anchors and screws and twist into place.  

The  .96-inch height of the First Alert PRC710 makes it the slimmest unit I tested, and combined with its relatively compact diameter (4.92 inches), it doesn't have the bulky, industrial look of some other detectors. Its smooth face and lack of any additional screens or controls really allows it to blend into its surroundings, making it convenient for those who want a minimal look. 

With this sleek appearance, some of the helpful features of similar models are sacrificed, like the informative LED screen of the X-Sense SC01, so keep that in mind if your prefer something a bit more interactive.

Types of smoke detectors

Battery: Smoke detectors can either be hardwired or standalone battery-powered units. Battery-powered detectors are easier to install than hardwired units and are unaffected in the event of a power outage. Some newer smoke detectors are designed with lithium batteries inside the unit that can last up to 10 years without needing to be replaced. Units that use replaceable batteries typically need new batteries every six months and are vulnerable to tampering and being disconnected during false alarms caused by non-emergency situations like cooking smoke or steamy showers.

Hardwired: Hardwired smoke detectors connect directly to your home's electrical wiring and typically have a backup battery in case of a power outage. These will initially need some electrical know-how or the help of a professional to be installed, but once the system is set up, it's pretty easy to disconnect and install new units whenever you need them. Yahoodain recommends hardwired smoke detectors since they're easy to interconnect, so if one goes off, they all go off. 

Photoelectric: Smoke detectors use either photoelectric or ionization sensors to detect smoke. Some, like the First Alert SA320 that we tested, use both. Photoelectric smoke alarms use an LED light to detect smoke and are more responsive to slow-burning, smoldering fires than ionization alarms. When smoke particles enter the unit, they disrupt the light beam, which reflects it into a sensor and activates the alarm. These types of sensors are generally superior to ionization sensors because smoldering fires tend to be more dangerous and can go unnoticed for longer periods of time than flash fires, or ones that develop very suddenly and intensely. They also cut down on unnecessary nuisance alarms that can cause people to remove the batteries out of frustration.

Ionization Sensors: These sensors are typically more effective at detecting flash fires. They do this by utilizing a small amount of radioactive material and placing it between two electrically charged plates. When smoke displaces the radioactive ions, the current between the plates is disrupted, and the alarm goes off. Ionization sensors have a higher chance of detecting nuisance alarms and tend to be much less effective at detecting smoldering fires. 

Smoke detector FAQs

Where should I install my smoke detector?

The NFPA recommends installing alarms inside and outside of every bedroom and on every level of your home, including the basement. Andler adds that, since smoke rises and begins gathering at the ceiling first, smoke alarms should be placed on your ceiling, not on the wall.  Andler also stressed the importance of having additional smoke detectors. In the event of a fire in your home, hallway smoke detectors can sound their alarms much earlier than a bedroom alarm. Andler also says that having a smoke alarm near — but not inside — the kitchen reduces the chances of false alarms. The Arizona Burn Foundation recommends keeping your detector at least 10 feet away from the stove.

How do I test my smoke detector so I know it's working?

Your smoke detector should have a "test" button. Press and hold it for a few seconds, and a high-pitched siren should start to sound. If there's no sound or the sound is nonexistent, it's time to replace the battery. Many insurance companies also advise replacing the batteries every six months regardless of the siren's loudness.

What certifications should I look for in a smoke detector?

Whichever smoke detector you choose, make sure it meets the standards of Underwriter Laboratories (UL), a third-party certification company that has been developing smoke detector standards for more than 40 years. The UL 217 code covers both "single station" smoke alarms that function as standalone units and "multiple station" smoke alarms that are interconnected so that when one goes off, they all go off. All the products we tested have this UL 217 certification, and our two combination smoke/carbon monoxide detectors, Nest Protect and First Alert SA320, also have a UL 2034 certification, which covers the CO detector.

How long are smoke detectors good for?

Smoke detectors can be effective for up to 10 years, but you still need to test them every month to make sure they're in working order. If you have a battery-powered unit, the batteries will need to be replaced every six months. Keep in mind that, according to Allstate, if your smoke detector also has an integrated carbon monoxide detector, those units do not last for 10 years and will need to be replaced sooner in accordance with the manufacturer's directions. 

Are hard-wired smoke detectors better?

If they're already installed in your home, hard-wired smoke detectors are generally more convenient than battery-powered models. Since they're powered by your home's existing electrical system, you don't have to worry about replacing batteries every year, and a backup battery ensures they'll still work if the power goes out. That being said, if they're not already installed, you'll need to incur the additional expense of hiring an electrician for proper installation.

Are 10-year smoke detectors good? 

Yes, several high-quality brands make "long-life" smoke detectors with permanent batteries that last for 10 years without replacement. Not only does this make them more convenient, it also eliminates the chance of batteries being removed due to those annoying low-life chirps. According to the NFPA, "In fires in which the smoke alarms were present but did not operate, almost half (46%) of the smoke alarms had missing or disconnected batteries. Nuisance alarms were the leading reason for disconnected smoke alarms." It's also important to remember that 10-year detectors still need to be tested regularly to ensure that they're in working order. 

Our smoke detector testing methodology

For this guide, I personally tested six smoke detectors after consulting with fire and building experts and doing extensive online research. 

I interviewed Patrick Andler, a fire investigator with 38 years of experience and a board member of the Arizona Burn Foundation. This organization — among many other functions — supplies free smoke detectors to low-income housing across Arizona. I also interviewed Nick Yahoodain, a home remodeler with more than 11 years of experience at Advanced Builders & Contractors. 

I also used my own experience installing hardwired and battery-powered smoke detectors in my own apartments and my parents' home, as well as my experience as a residential carpenter, which frequently required the relocation of hardwired units.

I installed each of the smoke detectors and tested it three times a day for three days. I performed a basic maintenance test according to the manufacturer's instructions (usually just by pressing the "test" button) and then sprayed the units twice with an aerosol spray that mimics real smoke. Most smoke detectors will not activate after a single spray, so you will need two three-second sprays to set them off. I found this to be the case with every unit I tested except for the First Alert SA320, which activated its alarm after only a single spray.  

I broke these tests up throughout the day to allow time for the spray to dissipate and the detectors to return to their working levels.  

I used several criteria to compare the units during testing. 

Installation: I installed each smoke detector on my ceiling according to the manufacturer's included instructions, timing how long it took and noting how helpful or detailed those instructions were. Aside from the hardwired First Alert, all the units used essentially the exact same mounting procedure, but I made sure to note any differences. 

Appearance: I took note of the size, weight, finish, and overall look of each smoke detector after installing units on a white ceiling.

Special safety features: I tested and evaluated each smoke detector's extra safety features, such as voice or light notifications, removal prevention, and more. For example, even though all the models I tested featured some kind of visual alarm component, the ultra-bright LED of the X-Sense SD01 was much more effective compared to the rest and could be beneficial to those with hearing loss. The straightforward voice commands of the Nest Protect might suit those who might get confused or disoriented by the single-alarm siren of the other models.  

Operation: Throughout my testing, I made sure to use and observe each mode the smoke detectors offered. This included their testing and silence buttons, how they utilized any LED lights, and whether or not they included carbon monoxide detection.

Maintenance: I took note of the approximate lifespan of each unit and the specifics of its battery replacement procedures. 

Alex Rennie

Freelance Reporter, Insider Reviews

Alex Rennie is a freelance writer who specializes in the home improvement, DIY, and appliance space. As a former residential and commercial carpenter for four years, Alex uses his hands-on experience to write buying guides, how-to articles, and product reviews. Before Insider, Alex was a full-time carpenter living in New York City. There, he worked as part of a team designing, building, and installing large furniture pieces, as well as performing a variety of home repair and maintenance projects. His expertise also extends to the landscaping and gardening space, supported by experience as a landscaping professional. Alex currently lives in Los Angeles, CA, and spends his free time exploring the beaches and mountains with his fiancé and their dog Louie.  Learn more about how our team of experts tests and reviews products at Insider here.

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Disclosure: Written and researched by the Insider Reviews team. We highlight products and services you might find interesting. If you buy them, we may get a small share of the revenue from the sale from our partners. We may receive products free of charge from manufacturers to test. This does not drive our decision as to whether or not a product is featured or recommended. We operate independently from our advertising team. We welcome your feedback. Email us at .

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