The 4 Best Basic Smoke Alarms of 2023

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We’re currently looking into UL's new smoke alarm standards, set to take effect 2024. We’re also researching the manufacturer X-Sense. More details here.

A house fire is a nightmare scenario. Working smoke alarms, and the early detection they offer, are an important element—maybe the most important—to help ensure the safety of you and your loved ones.

After putting in more than 70 hours researching fire safety, interviewing five experts, and reading well over a hundred pages of smoke-alarm data, we recommend the First Alert SA511CN2-3ST Interconnected Wireless Smoke Alarm with Voice Location as the primary alarm in a comprehensive whole-home fire-protection system.

Available in a two-pack, these alarms can interconnect so that they all sound at once. They also tell you which room the fire is in.

*At the time of publishing, the price was $56.

The UL-certified First Alert SA511CN2-3ST alarm comes in a two-pack, and the units (and any additional ones) can interconnect so that if one sounds, they all sound, which can give you additional time to identify the problem and evacuate. This wireless-connection setup is internal to the alarms and does not require a phone app. You can also designate each unit by location so that if an alarm is tripped, all of them indicate which room the hazard is originating from. The First Alert SA511CN2-3ST is the only model that combines all of those features in one bundle—and at a price that's just slightly above average for the category, it's a good value. Also, because it has a voice alert rather than a beep or a tone, our interviewed experts told us, it's more apt to wake a sleeping child.

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Similar to our pick but also equipped with a carbon monoxide alarm, these photoelectric smoke alarms with voice alerts can interconnect and allow you to identify threats by location.

If you’re shopping for a smoke alarm and don't already have carbon monoxide alarms installed, we recommend using the First Alert SCO501CN-3ST Combination Smoke and Carbon Monoxide Alarm with Voice Location on each floor. This photoelectric alarm is identical to our main pick save for an added carbon monoxide alarm, which detects CO from broken or improperly installed chimneys or fuel-burning appliances such as some furnaces, dryers, or water heaters. That feature adds notable cost, with a single unit typically priced a little less than the two-pack of our top pick.

The First Alert SA303CN3 is slightly better at detecting fast, flaming fires than the rest of our picks, but it's generally slower to go off, and it's best as a supplemental part of a system.

*At the time of publishing, the price was $8.

For the most complete and effective smoke alarm system, we also recommend adding one First Alert SA303CN3 Battery Powered Smoke Alarm per floor. This alarm employs a different detection technology, ionization, so it is slightly better at detecting fast flaming fires than our other picks. It's not as good as a photoelectric alarm in detecting slow, smoky, smoldering fires—and in studies, ionization alarms have tended to sound a few critical minutes later—which is why we recommend it for supplemental use and not as your primary alarm system.

The PR710 can't interconnect like our picks, but it does have a 10-year sealed battery, which some states and municipalities require.

*At the time of publishing, the price was $21.

The smoke alarms we recommend use AA or 9V batteries, but if your city or state requires a 10-year sealed battery in your smoke alarm, we like the First Alert PR710 Slim Photoelectric Smoke Alarm with 10-Year Battery. This UL-approved alarm has no connectivity, so it lacks the whole-house protection of our main picks, but otherwise it should offer the same smoke-sensing effectiveness. Research has shown (PDF) that 10-year batteries may not actually last 10 years, so we still recommend testing them on a schedule and not falling into complacency. First Alert also sells the P1210E 10-Year Battery Photoelectric Smoke Alarm, Slim Profile with Safety Path Light, which is the same alarm but with an added pathway light that turns on when the alarm is activated.

Available in a two-pack, these alarms can interconnect so that they all sound at once. They also tell you which room the fire is in.

*At the time of publishing, the price was $56.

Similar to our pick but also equipped with a carbon monoxide alarm, these photoelectric smoke alarms with voice alerts can interconnect and allow you to identify threats by location.

The First Alert SA303CN3 is slightly better at detecting fast, flaming fires than the rest of our picks, but it's generally slower to go off, and it's best as a supplemental part of a system.

*At the time of publishing, the price was $8.

The PR710 can't interconnect like our picks, but it does have a 10-year sealed battery, which some states and municipalities require.

*At the time of publishing, the price was $21.

We spoke to a number of people in the fire-safety industry: Joseph Keenan, assistant fire marshal of the Burlington (Vermont) Fire Department; Judy Comoletti, division manager for public education at the National Fire Protection Association (now retired); John Drengenberg, consumer safety director at UL; Timothy Sendelbach, editor-in-chief of Firehouse Magazine, who has 30 years of experience in fire and safety services; and Tom Kiurski, training coordinator and director of fire safety education for Livonia, Michigan, as well as a columnist with FireRescue1. Kiurski has 35 years of experience in the fire services.

In addition, we spent hours reading hundreds of pages of smoke-alarm studies, such as the NFPA's massive "Smoke Alarms in U.S. Home Fires" report, the National Center for Healthy Housing's "Evaluation of the ‘10-Year’ Smoke Alarm Project" report (PDF), and Vision 20/20's "The Smoke Alarm Problem" report (PDF), among many others. Note that the National Center for Healthy Housing is partially funded by The Home Depot Foundation.

Working smoke alarms are essential in any home, but you should treat them as just one piece of a comprehensive fire-safety plan. Your plan should include other safety items such as fire extinguishers and escape ladders, but most importantly, you should base your plan on an awareness of what to do in case of a fire. Firehouse Magazine's Timothy Sendelbach told us, "The best advice I can offer is to practice fire drills, using the test button on the alarm, to familiarize family members with the sound and recommended actions to be taken upon activation." For more information, we recommend the NFPA's page on how to make a home fire escape plan.

It's important to understand your state and local smoke alarm regulations before making a purchase. We found that many regulations are at odds with one another—and with our recommendations. No company sells a one-size-fits-all smoke alarm capable of satisfying the requirements of every state.

For example, our main recommendation, the First Alert SA511CN2-3ST Interconnected Wireless Smoke Alarm with Voice Location, uses two AA batteries, but many states now require models with 10-year sealed batteries. We have a recommendation to meet that requirement, as well.

First Alert's site has a nice interactive map that can help you get started on understanding your state's requirements. We also recommend contacting your local fire department for more information specific to your area.

There are two very distinct types of smoke alarms: photoelectric and ionization. Each sensing technology has its advantages, and as training coordinator and fire safety educator Tom Kiurski told us, "I recommend you have both types in your home." This is also the official position of the NFPA and UL (PDF).

Photoelectric sensors are set off when smoke enters the alarm and deflects a beam of light onto a photocell. For slow, smoky, smoldering fires, photoelectric alarms are far more sensitive and effective than ionization alarms. They’re slightly less effective at sensing fast, flaming fires—but the difference in performance is small enough to tilt us toward a photoelectric model as our primary choice and an ionization model as a supplementary alarm.

Ionization alarms are less expensive and good at detecting the small particles of fast-burning flaming fires, but they’re not as good with smoldering, smoky fires. Ionization alarms contain a minuscule amount of radioactive material (americium-241) that ionizes oxygen and nitrogen atoms in the air, a process that creates a small electrical current in the sensing chamber. The alarm monitors this current, and when smoke enters the chamber, the current is disrupted and the alarm sounds.

A number of studies have quantified the two alarm types’ differences in response time. The Dallas–Fort Worth NBC affiliate simulated a smoldering couch fire with a variety of smoke alarms placed 15 feet away. The two photoelectric alarms sounded at just under 20 minutes, whereas the two ionization alarms sounded at 22 minutes and 28 minutes. According to the fire marshal supervising the test, by the time the second ionization alarm went off, the fire was at the "free-burning stage [when] it was completely unsurvivable."

There's a good reason not to rely entirely on dual-sensor smoke alarms.

On fast-burning, flaming fires, a study (PDF) conducted by UL and the Fire Protection Research Foundation found that ionization alarms responded about a minute faster than photoelectric alarms on average. That may not sound like much, but a home can reach "untenable conditions" in just three minutes,1 according to a National Institute of Standards and Technology study (PDF). You’re likely to have less time to escape in a fast-spreading fire, so that minute can be crucial to your survival. As UL consumer safety director John Drengenberg told us, "You never know what type of fire will occur." In other words, ionization alarms play an important part in a complete system.

Considering that both sensor styles have their benefits, you might conclude that your best bet is a dual-technology alarm, which has both photoelectric and ionization sensors in a single unit. But there's a good reason not to rely entirely on these combo alarms. Ionization sensors are prone to nuisance alarms, mostly from cooking and shower steam, and people often disable them over that kind of annoyance. So although Joseph Keenan, assistant fire marshal in Burlington, Vermont, recommends that both types of alarm should be present in a home, in our interview he made sure to specify that they should be installed as "separate devices ... not as dual-sensor devices." He explained further: "If nuisance alarms occur with the ionization sensor, residents will take down the device and be left without detection." Splitting the two types of sensors allows you to place each one in an ideal location.

Research backs Keenan up on the problem of disabled alarms. A study of smoke alarms in rural Alaskan homes found an "8-fold higher incidence of nuisance alarms in homes with ionization alarms." In addition, the same study found that, due to nuisance alarms, "ionization smoke alarms were almost 5 times more likely to be disconnected 6 months after installation compared with photoelectric alarms." A 1995 Texas A&M study (PDF) that took into account disabled alarms concluded that "the probability of a fatality due to the failure of the ionization detector to detect a flame ignition fire is 19.8%." With photoelectric detectors, that number dropped to 3.99%. Given those stats, it's easy to see why Keenan told us that "resident behavior is the biggest challenge we face with smoke alarms." This is also the reason the International Association of Fire Fighters, the largest firefighter union in the world, supports legislation (PDF) making photoelectric alarms a mandatory requirement for fire and building codes.

In making our picks, we also considered two other major factors:

Interconnected alarms: One way to increase the fire protection of your home is to get interconnected smoke alarms so that when one goes off, they all do. Keenan referred to this setup as "the biggest feature which makes a smoke alarm effective." The main advantage is that such an arrangement allows for "early notification of all residents within the dwelling, no matter where the problem originates."

Many states require interconnected, hardwired smoke alarms with a battery backup in all new construction. Retrofitting this kind of wiring into a house is expensive, so now some new battery-powered smoke alarms use a basic wireless technology to link units. Overall, our research convinced us that recommending interconnected models should be a main focus of this guide.

Affordable and accessible models: We wanted to find alarms that are relatively easy to set up and for which the cost is as little of an obstacle as possible. So we looked primarily at basic or "dumb" models that run on AA batteries. (We have more to say on batteries in the Maintenance section.) Smart smoke alarms usually cost more than twice the price of our pick here (and that cost compounds when you need to purchase multiple units). When it comes to actual smoke- and fire-detection abilities, the difference between the best smart alarms and the best dumb alarms is not significant enough to be a dealbreaking factor. The major difference is that smart models allow you to monitor your home's smoke alarms remotely via an app. Beyond that capability, smart smoke alarms offer additional features and smart-home integration. To learn more, see our separate guide to the best smart smoke alarm.

Some other basic alarms have a number of features that we didn't prioritize, such as lights or specific alert noises. Those are nice, but as training coordinator and fire safety educator Tom Kiurski told us, "The options are what drive up the price." He added that "having plenty of working smoke alarms is most important."

Smart smoke alarms are pricey, but unlike traditional ones can alert you to a problem even when you aren't home. The Google Nest Protect is the best model.

Available in a two-pack, these alarms can interconnect so that they all sound at once. They also tell you which room the fire is in.

*At the time of publishing, the price was $56.

For your primary line of defense, we recommend the First Alert SA511CN2-3ST Interconnected Wireless Smoke Alarm with Voice Location. This is a photoelectric alarm, so it's effective against both slow-burning, smoldering fires and fast-burning, flaming fires. It's sold in a two-pack, and the two units link together through a wireless signal—and can combine with additional units—so that they all sound at once. In addition, you can preset each unit to a location so that when an alarm goes off, all of the units indicate which room the fire is in. The alarm is a voice alarm, which research indicates is more effective in waking small children than a simple tone. The First Alert SA511CN2-3ST is the only alarm we found that combines the voice alarm, the location feature, and the wireless connection all in one unit—at a price that's merely on the high side of average for the category.

The wireless connection is the most important feature for early detection of a fire. Upon installation, the SA511CN2-3ST alarms connect to one another with just a couple of button pushes on your part. As for the range of the wireless connection, the instruction manual (PDF) for the SA511CN2-3ST says that each one has a limit of about 50 feet, although "[s]ome features of a home, such as the number of floors, number/size of rooms, furniture and types of building materials used may reduce the range of the Alarms." The company gives examples such as "suspended ceilings, ductwork, large metallic appliances (refrigerators) and metal studs."

The SA511CN2-3ST units use what is called a mesh network, meaning that the signal is not linear from one unit to the next. The benefit of this technology, according to First Alert, is that "the mesh network of alarms re-routes and resends the signal via the other alarms, providing a greater chance all alarms will receive the signal." It's important to note that these alarms are connected only to one another and have nothing to do with a phone app or a household Wi-Fi connection. You can expand the network to a maximum of 11 alarms. Also, the alarms link "through the software using 65,000 security code combinations," according to First Alert, minimizing the chance of interference from a duplicate code in a nearby home.

Because they’re interconnected, the SA511CN2-3ST alarms not only give you an early warning but also tell you where the problem is originating from. During initial setup, you assign each alarm a room location. When the alarms go off, they all announce the source alarm's location. As training coordinator and fire safety educator Tom Kiurski told us, "Vocal smoke alarms are recommended if you have children between 4 and 12 years of age, because studies show they respond better to a familiar voice, as opposed to something that can fall under ‘white noise.’"2

The SA511CN2-3ST two-pack typically sells for about $65, making this model slightly more expensive than standard battery alarms, which are usually around $25 or less each. We’ve concluded that the SA511CN2-3ST's unusual combination of features is worth the added cost—and relative to smart smoke alarms, it's a bargain.

The initial setup of the SA511CN2-3ST is predictable, in the sense that it involves light screwdriving and some alarm sounds blaring in your face. To attach the mounting plate to the wall, you may need to drill and drive a few new drywall screws, but no heavy-duty mounting hardware or stud finding is necessary for this task. In a nice touch, the units come with AA batteries included. And although assigning the units to certain rooms and pairing them together was loud and a little confusing, we followed the included instructions, and everything worked correctly the first time. Finally, a reader asked us if you have to go around to each paired alarm to manually turn each one off during an alarm or test. The answer is no—conveniently, when you deactivate one, they all go silent.

We recommend using these First Alert alarms as your principal line of defense, with one on each floor and one in each bedroom, adding more units to account for the size of your house. We also believe it's important to have a carbon monoxide detector as well as an ionization alarm on each floor for added protection against the hazards they’re suited for, and we have suggestions on those below.

The main downside of the SA511CN2-3ST is that this wireless unit is available only with photoelectric sensors—none of First Alert's ionization alarms have wireless connectivity. For maximum protection against both slow-burning, smoldering fires and fast-burning, flaming fires, your home needs both types of sensor, and the best-case scenario is that they’re all linked to the same system. But that isn't possible with First Alert alarms.

Another drawback of the SA511CN2-3ST is that it isn't particularly attractive. It looks like, well, a smoke alarm. First Alert has other models with a thiner look (such as the PR170), but to get the wireless connectivity, the photoelectric sensor, and the voice and location alerts in a single unit, your only option is the model we’re recommending. The good news is that once smoke alarms are installed, everyone stops noticing them.

Similar to our pick but also equipped with a carbon monoxide alarm, these photoelectric smoke alarms with voice alerts can interconnect and allow you to identify threats by location.

Carbon monoxide is a deadly, odorless, colorless gas that can spread through a home as the result of a malfunctioning or improperly installed chimney or combustion appliance such as a gas stove, a gas boiler, a water heater, a propane range, or a wood stove, according to the Environmental Protection Agency and other sources. If you don't already have CO alarms, we strongly recommend including a few First Alert SCO501CN-3ST Combination Smoke and Carbon Monoxide Alarm with Voice Location units in your interconnected system.

This model offers the same features as our main pick (photoelectric sensor, wireless interconnectivity, voice alarm, and location alerts) and adds a carbon monoxide sensor. That CO detector adds a good bit to the price—currently a single SCO501CN-3ST unit is just barely cheaper than the two-pack of our top pick—so we made this model a separate recommendation in case you’re already covered with a stand-alone CO detector.

The First Alert SA303CN3 is slightly better at detecting fast, flaming fires than the rest of our picks, but it's generally slower to go off, and it's best as a supplemental part of a system.

*At the time of publishing, the price was $8.

To have the most complete fire-detection system, we recommend adding a First Alert SA303CN3 Battery Powered Smoke Alarm to each floor. This model is an ionization alarm, so it's designed to be better than our other picks at detecting a fast, flaming fire. It's not as good as the others at detecting smoky fires, however, so we don't recommend it as a primary alarm. According to our research, ionization alarms are also prone to nuisance alarms, particularly from shower steam or cooking smoke, so make sure to place them accordingly.

The PR710 can't interconnect like our picks, but it does have a 10-year sealed battery, which some states and municipalities require.

*At the time of publishing, the price was $21.

Many states (such as California) and municipalities (such as Phoenix) require smoke alarms with 10-year batteries. For these areas, we recommend the First Alert PR710 Slim Photoelectric Smoke Alarm with 10-Year Battery, which, as its full name indicates, has a photoelectric sensor and a fully sealed 10-year lithium-ion battery. The alarm has a low profile from the wall of about an inch, and it honestly looks a lot more streamlined than our main pick (though it doesn't have the voice alert or wireless connectivity). It typically costs around $25, making it a relatively inexpensive option. For roughly a few dollars more, First Alert sells a similar model with a pathway light that turns on when the alarm activates.

One purported benefit of the sealed battery is that it offers a higher degree of tamper resistance because it is not removable. But one important thing to understand is that when you take the alarm unit off the wall, it deactivates.

Even though this alarm is sold with a 10-year battery, it still requires testing on a regular basis. A study (PDF) performed for the Centers for Disease Control and Prevention did a long-term follow-up on alarms and found that 14% of those using lithium-ion batteries had dead batteries before the full 10 years were up.

As for the specifics of smoke alarm location within a room, there are actually quite a few areas to avoid.

The National Fire Protection Association's recommendation for smoke alarm placement is that you have one on each floor and one in each bedroom. So for a typical two-story home, that's one in the basement (preferably near the stairs to the first floor), one on the first floor, and one in the second-floor hallway, with an additional unit in each bedroom or sleeping area. You should not place one in a garage (due to car exhaust) or in areas that have temperatures lower than 40 degrees Fahrenheit or higher than 100 degrees Fahrenheit.

As for the specifics of smoke alarm location within a room, there are actually quite a few areas to avoid. First Alert's FAQ states, "Install your alarms at least 20 feet from appliances like furnaces and ovens, which produce combustion particles. Alarms should be at least 10 feet from high humidity areas like showers and laundry rooms, and at least 3 feet from heat/AC vents."

It's important to check your smoke alarms on a regular basis. Training coordinator and fire safety educator Tom Kiurski recommends doing so monthly and says to "change the battery as suggested by the manufacturer." According to the NFPA, "Manufacturers’ instructions are specific to the batteries (brand and model) that must be used. The smoke alarm may not work properly if a different kind of battery is used." And don't use rechargeable batteries: The manual for the First Alert SA511CN2-3ST (PDF) says, "Never use rechargeable batteries since they may not provide a constant charge."

If a smoke alarm has no printed date, it was made before 2000 and should be replaced.

First Alert says batteries should be replaced about once every year. Most alarms start to chirp when the batteries are low. Make sure not to treat such sounds as nuisance alarms—don't ignore them.

Finally, it's important to know the age of your smoke alarm. Kiurski told us that alarms need replacing "after ten years of age." He continued, "You can find out when your alarm was made by looking at the unit itself. It is required by law to be on there since the year 2000." He said that if a smoke alarm has no printed date, it was made before 2000 and should be replaced.

The alarms we recommend all sound at 85 decibels, which should be loud enough for most people, but if you have hearing loss or are just a heavy sleeper, there are other options to consider. Some smoke alarms, such as the Gentex 7139LS Photoelectric Smoke Alarm with Plug-In Line Cord, ADA Strobe and Battery Backup, include a strobe alert, which may help. More comprehensive systems, like the Lifetone HLAC151 Bedside Fire Alarm and Clock and the SafeAwake, are also available; when these bedside units pick up the alarm sound from a standard smoke alarm, they flash lights, emit a loud low-frequency alert, and vibrate a pillow shaker. The NFPA has more advice on how to start locating the best smoke alarm for your specific situation.

UL recently released a new set of standards for smoke alarms, to take effect in 2024. We’re in the process of understanding what these new changes entail and how they will affect the smoke alarm industry.

We’re also currently looking into X-Sense smoke alarms. They have products that are similar to our picks, most notably the X-Sense XS01 Wireless Interconnected Smoke Alarm (available in a three pack or a six pack).

With placement on the shelves of Home Depot, Kidde is the most prominent competitor to First Alert, but its overall track record is, in a word, disturbing. In 2018, the company recalled more than 450,000 dual-sensor smoke alarms; in 2016, it recalled 3.6 million smoke/CO alarms, and in 2014, it recalled 1.2 million smoke/CO alarms. In addition, since 2005, Kidde has enacted three separate fire extinguisher recalls of 470,000 units (2005), 4.6 million units (2015), and 40 million units (2017). Worst of all, in early 2021, a federal judge ordered Kidde to pay a $12 million civil penalty "in connection with allegations that the company failed to timely inform the Consumer Product Safety Commission (CPSC) about problems with fire extinguishers manufactured by the company." For these reasons, we can't, in good conscience, recommend any Kidde products to our readers.

Although First Alert is not immune to recalls (it recalled nearly 150,000 smoke alarms in 2006 and roughly 600,000 fire extinguishers in 2000), none of them are recent or on the scale of what Kidde has had to do.

As of our current research, we know of no other alarms that combine wireless interconnectivity with a photoelectric sensor and voice and location alerts.

We did find alarms from Universal Security Instruments that use a third smoke-detecting technology called IoPhic, which is proprietary to the company and appears to be a form of ionization alarm designed to reduce nuisance alarms. The technology looks good on paper (PDF), but none of our experts mentioned it (Firehouse Magazine's Timothy Sendelbach was unfamiliar with it.) The alarms are UL-approved. It's a relatively new technology, and we will be keeping an eye on it as it gets a foothold in the industry.

In the future, we expect the gap to narrow between smart smoke alarms and wireless, interconnected (but not app-connected) basic models like our top pick in this guide. Smart alarms can offer valuable additional features—but at more than double the price, they can be far more expensive than our picks, especially when you’re outfitting an entire house with multiple units. For future updates to this guide, we will consider the more feature-rich basic units. As the devices evolve, we will make the call as to which alarm gives you the most protection for the best value.

Doug Mahoney

Doug Mahoney is a senior staff writer at Wirecutter covering home improvement. He spent 10 years in high-end construction as a carpenter, foreman, and supervisor. He lives in a very demanding 250-year-old farmhouse and spent four years gutting and rebuilding his previous home. He also raises sheep and has a dairy cow that he milks every morning.

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