The 6 Best Smoke Detectors

Smoke Sensor Type: Photoelectric | Battery-Powered or Hardwired: 2xAA Batteries

For a top-notch battery-powered option and our favorite overall smoke detector, check out the First Alert SCO7CN. This alarm is straightforward to install and emits a traditional alarm and a spoken call to evacuate. It detects both smoke and carbon monoxide and tells you the maximum amount of carbon monoxide detected after an alarm has been triggered (in parts per million/ppm). The alarm is incredibly loud.

While the First Alert SCO7CN is a great basic alarm, it doesn't feature all the bells and whistles. For instance, it cannot be linked with other alarms to create an interconnected system, and this model lacks an escape light. The initial setup is a little more involved, as the programming process to set the location of the alarm is far from intuitive. All told, it's a great battery-powered alarm and is an excellent choice for those requiring a dual smoke/carbon monoxide alarm that will let you know the location of the alarm.

Smoke Sensor Type: Photoelectric | Battery-Powered or Hardwired: 2xAA Batteries

For those who don't need the voice warning, the First Alert SCO5CN is a great premium battery-powered combination smoke and CO alarm that doesn't include the extra chatter. This unit has a photoelectric sensor to help detect fires when they are still smoldering and an electrochemical CO sensor. It is super quick and easy to install, and the siren is loud to alert you in the case of fire or carbon monoxide accumulation. Thanks to a slide-out battery drawer, you can change the batteries without removing the alarm from its mount, and we appreciate that you can mute the low battery chirp for 8 hours — perfect for those instances where that chirp starts in the middle of the night.

Our biggest complaint is that the First Alert SCO5CN does not offer interconnected system compatibility, where one alarm sounding will trigger all the others. Furthermore, it only comes with one type of smoke sensor. That means you'll need to purchase an additional type with an ionization sensor to meet the recommendations of the National Fire Protection Association. For this reason, we recommend considering another option if you only want a single brand and model of smoke detector throughout the home. That said, we think this is a great battery-powered combo smoke/CO alarm, particularly if you don't want to mess with programming locations for voice prompts and just need a simple siren.

Smoke Sensor Type: Ionization | Battery-Powered or Hardwired: 3xAA Batteries

If you don't have a hardwired detector system and have always wanted to add a series of interconnected alarms, then the Kidde 21026044 Wireless is a great option. This battery-powered alarm is straightforward to install, with a series of eight switches on the back that let you select a unique wireless code for your alarm system. Any other alarm set with the same code will automatically go off when any interconnected alarm is activated. However, there is a limit of 24 total Kidde devices, with 18 being units that trigger an alarm (12 can be smoke alarms). Many building codes require an interconnected alarm system for new construction. This model's wireless interconnectivity could be a much easier and less expensive option than running wires throughout your home.

We discovered that the “Hush” button could be a little finicky. You should be able to hit this button on the initiating alarm, and it should silence all of the others, but we found that it took a few tries before the other alarms would silence. There is also no straightforward way to precisely know which alarm triggered the others because there aren't voice announcements like some other systems have. Although these aren't trivial flaws, the Kidde 21026044 is one of our favorite battery-powered options for setting up an interlinked alarm system, especially when you're shopping on a budget.

Smoke Sensor Type: Ionization | Battery-Powered or Hardwired: 9-Volt Battery

If you are on a tight budget and on the hunt for a bare-bones smoke alarm, the Kidde i9050 is a great option. This ionization smoke alarm is quick to install and has all the basic features you may want, allowing you to minimize the amount you need to spend if you are replacing all the alarms in your home. The locking pins are also a nice feature to reduce the chance of theft or someone tampering with the alarm.

However, when it comes to advanced features, the Kidde i9050 is quite limited. It can't be linked to other alarms, so be sure to check local regulations to ensure that your overall system complies. You may need to add additional photoelectric smoke alarms or carbon monoxide detectors to your home. Still, if you're shopping on a limited budget, then the Kidde i9050 is one of the top models we recommend.

Smoke Sensor Type: Photoelectric | Battery-Powered or Wired: Hardwired with Lithium Battery Backup

If you are looking for a new smoke alarm that packs as many smart features as possible, then the First Alert OneLink Alexa Safe & Sound is a fine option. This top-tier smoke alarm can act not only as a smoke and carbon monoxide sensor but also includes a built-in Alexa-enabled speaker. It will send notifications to your phone if an alarm is triggered, allowing you to remotely monitor your home while you're away or hush false alarms right from your smartphone. You can play music with streaming services like Spotify or iHeartRadio, and the speaker sounds pretty good for being in a smoke detector. There is also a customizable night light that you can automatically turn on in the evening.

Regrettably, all of these features make the Safe & Sound one of the priciest options we tested. The installation is more challenging because this alarm has to be wired in place and paired with the OneLink and Amazon Alexa apps. The steep price makes it unlikely that you want to install one in every room of your home. You can still connect this alarm to other compatible non-smart smoke sensors or other Safe & Sound units to get an interconnected alarm system for quite a bit less. We think it's also an excellent choice if you want to add more Alexa-enabled speakers to your home and want a smart smoke detector for your Alexa or Apple HomeKit system. Otherwise, it may have more smarts than most people want or need in a smoke alarm.

Smoke Sensor Type: Photoelectric & Ionization | Battery-Powered or Hardwired: Hardwired

The National Fire Protection Association (NFPA) recommends having a mix of photoelectric and ionization smoke alarms in your home for the best chance of an early alert to any problem. While most smoke alarms only have a single sensor, the First Alert 3120B Hardwire Dual has both to cover all your bases. The alarm includes a pre-stripped wiring adapter and provides the option to interlink with other compatible alarms so that any alarm will trigger all of them. It also has a battery backup in case your power goes out.

We wish the First Alert 3120B Hardwire Dual had an integrated carbon monoxide sensor, which could further reduce the need for additional alarm units. We think it's worth noting that not all hardwired smoke alarms are compatible with one other when creating an interconnected system, so you should double-check if you are just trying to replace a single alarm. Regardless, the First Alert 3120B Hardwire Dual is a terrific option for anyone shopping for dual smoke sensors in a simple package.

Smoke Sensor Type: Ionization | Battery-Powered or Hardwired: Battery-Operated

If you liked the looks of the First Alert SCO7CN but need a new ionization smoke alarm, then the Kidde 21026043 KN-COSM-BA is a fantastic option for you. This unit is powered by three AA batteries and features an integrated carbon monoxide detector. It's a breeze to install and features not only the typical carbon monoxide and smoke alarm patterns - but also voice commands warning you to evacuate. This unit can also inform you of the peak concentration of carbon monoxide measured once it hits a level of 100 ppm or higher. We recommend only checking this after any potential danger has cleared and the source of carbon monoxide has been mitigated.

Although the Kidde 21026043 KN-COSM-BA is a solid standalone option, it cannot link to other smoke detectors. It also cannot be programmed with a location, so it won't immediately alert you to the location of the triggered alarm. Still, this model is one of the better combo smoke/carbon monoxide alarms if you need a battery-powered unit and are looking for another ionization sensor.

Smoke Sensor Type: Split-Spectrum | Battery-Powered or Hardwired: Both options available

If you already have a Google-based smart home and want to add an intelligent smoke detector to the mix, then the Nest Protect is an excellent choice. Available in both battery-powered and hardwired versions, this smoke alarm easily integrates with your existing Nest products. It lets you remotely keep an eye on things, alerting you with push notifications if an alarm sounds. Even better, it can automatically activate a Nest camera so you can see what's going on or turn off your heating system if it detects elevated levels of carbon monoxide. The Nest Protect has smoke sensors for both flaming and smoldering fires and a motion-activated light to help you during a power outage.

Unfortunately, the Nest Protect is one of the more expensive smoke alarms we have tested to date. It also isn't compatible with triggering any other smoke detectors, so be prepared to spend a serious chunk of money if you're hoping to get an interconnected alarm system and a Protect unit in every room. There aren't many options to use the Protect as a trigger for other smart devices, like having your lights turn on if an alarm is initiated, though this can change as smart systems get updated. The Nest Protect is one of our favorite options if you already have a Nest system and want a smart smoke alarm, but you need to be prepared to pay for it.

Smoke Sensor Type: Photoelectric | Battery-Powered or Hardwired: Both options available

The Onelink Smart Smoke + Carbon Monoxide smoke alarm is a slightly more budget-friendly option than many other smart smoke detectors on the market. It has all the necessary features you would want, like the ability to test/silence the siren right from your smartphone or alert you that an alarm has sounded if you aren't home. It's available in both battery and AC-powered versions, and both can connect to other compatible alarms to create an interconnected system. This is especially handy with the hardwired version, as you can wire it into an existing First Alert or BRK hardwired alarm system, adding smart features at a much lower cost than buying a smart smoke alarm for each room in your home.

Although this product does well with the basic smart features, advanced features are limited. It is compatible with Alexa and Apple HomeKit. However, it's hard to set it to trigger actions, such as turning on the lights when an alarm sounds or turning off your heater if it detects increased levels of carbon monoxide. Additionally, the remote monitoring only works if your home wireless network is powered up and functioning. Those who need a more reliable setup may want to consider higher-end professional monitoring services. The Onelink Smart Smoke + Carbon Monoxide is an excellent option if you're hoping to add some smart features to your smoke alarm system, but you're trying to save some cash.

Smoke Sensor Type: Ionization | Battery-Powered or Hardwired: Hardwired

The First Alert SC9120B is the perfect option if you need a hardwired alarm that is not only a smoke detector but also a carbon monoxide sensor. This smoke detector has a 9-volt battery backup to provide alerts even when your electricity is out. It can connect to other hardwired alarms to maximize your early warning in the case of an emergency, and it's not too much of a hassle to install with the included pre-stripped wiring adapter. It also has a latching alarm, so you can identify which unit initiated the alarm even after the siren has subsided.

This alarm is a fairly run-of-the-mill combination smoke and carbon monoxide hardwired alarm. It has a slightly larger mounting/trim plate than some of the other models, which can be handy if you want to cover up any damage near your electrical box, but it's more noticeable than we would prefer for most installations. The First Alert SC9120B is one of our favorites if you want a hardwired smoke alarm that doubles as a carbon monoxide detector.

Why Trust GearLab

We started our review process with thorough research into the smoke detector market before settling on the selection in this review. We rated and compared performance by installing them in various locations around the house, looking at the amount of effort it took to install them, all the different features these products have, and how well they can integrate into an existing alarm system. Throughout our testing, we triggered alarm after alarm while listening to siren after siren (after siren!) to assess each model's performance.

Our expert smoke detector reviewer, David Wise, has made a career of professionally reviewing and evaluating a wide variety of consumer products and electronics. He has a formal education as a mechanical engineer and is a DIY enthusiast, utilizing this experience in the creation and execution of our rigorous side-by-side testing and evaluation process for smoke alarms.

Analysis and Test Results

We broke down our testing and evaluation process into a series of different rating metrics. We use each product's weighted performance in each metric to determine our overall rankings, but recommend you pay closer attention to the metrics that are most important to you.

Ease of Installation

As it's one of the first things you will have to tackle when getting a new smoke detector, we started by rating and scoring the hassle it took to get each smoke alarm installed and configured. Generally, we have found that the battery-powered models are a bit easier to install, as you just need to attach the mounting bracket to the wall, insert batteries, and clip on the alarm. This is true for the First Alert SCO7CN, the First Alert SCO5CN, or the Kidde i9050, the Kidde 21026043 KN-COSM-BA.

There are a few other battery-operated models, but they each offer wireless connectivity, so they take a little more time and effort to configure. The Kidde 21026044 Wireless is the easiest of these. You just need to pick a code with the eight switches on the back, and any alarm that shares the same code should automatically connect (up to a limit of 24 interconnected devices with 12 being smoke alarms).

The battery-operated Nest Protect and the OneLink Smart Smoke + Carbon Monoxide are easy to install. Still, it takes a little more time to get their smart features up and running because you usually need to download an app, make an account, and pair it to your mobile device. You need to do the same thing with the First Alert OneLink Alexa Safe & Sound, but it takes some extra time to wire it up to power, so it has one of the most involved installations of our test group. The wired versions of the Nest Protect and the OneLink are about the same level of difficulty to install as the First Alert OneLink Alexa Safe & Sound.

The remaining hardwired alarms aren't too hard to install, provided your home is already set up for a hardwired system. Most of them, such as the First Alert 3120B Hardwire Dual and the First Alert BRK SC9120B, come with a pre-stripped wiring harness, so it should be quick and easy to remove your old alarm and attach the new ones with a pair of wire nuts. You will need to strip the other wire and do a little more work if you have an interconnected system, but it isn't a huge hassle.

Detection Sensor Type

Next, we compared the types of detection sensors present in each of these products. Smoke alarms come with two different types of sensors: ionization and photoelectric. Ionization sensors use a tiny trace amount of radioactive material to detect smoke — nothing to be concerned about — and are generally more sensitive to flaming fires. Photoelectric sensors rely on a light source and sensor and are typically triggered faster by smoldering fires. To give you the best chance of early detection, the National Fire Protection Association recommends having both types of sensors in your home.

Luckily, some smoke detectors, like the Nest Protect and the First Alert 3120B Hardwire Dual, include both types of sensors in a single unit, giving you the best chance of detecting both flaming and smoldering fires. The Nest Protect also has an integrated carbon monoxide sensor.

A handful of other smoke detectors also have integrated carbon monoxide sensors, even though they only have a single type of smoke-sensing sensor. The First Alert BRK SC9120B and the Kidde 21026043 KN-COSM-BA have ionization smoke sensors, as well as carbon monoxide detectors. The First Alert SCO7CN, the First Alert SCO5CN, the First Alert OneLink Alexa Safe & Sound, and the OneLink Smart Smoke + Carbon Monoxide all have photoelectric smoke sensors, in addition to a carbon monoxide sensor.

Interconnect Abilities

Many new building codes are mandating an interconnected smoke alarm system so that any alarm detecting smoke will trigger all of the others to sound. Luckily, many of the products we tested have this ability, which is common among hardwired alarms, like First Alert's 3120B Hardwire Dual and BRK SC9120B. These units have a dedicated wire just for linking to other units. However, you need to check that the wiring in your house and your other alarms are compatible. Usually, they will only work with other alarms from the same manufacturer.

The hardwired version of the OneLink Smart Smoke + Carbon Monoxide and the First Alert OneLink Alexa Safe & Sound can also do this, with the bonus of being able to link with non-smart compatible alarms. This lets you save some money by adding only a single smart alarm to achieve a smart system. The wired and wireless Nest Protect can link to each other but not too different alarms.

The Kidde 21026044 Wireless can also be linked and is one of the simplest and least expensive ways to set up a connected system, even if you don't have hardwired alarms. You just pick your code, and each alarm should automatically link. You need to locate the initiating alarm for the “Hush” feature to automatically connect to the other blaring alarms.

Other Features

Finally, we compared any additional features these products have. Some of these products will give you verbal warnings in addition to the typical siren alarm. All of the smart smoke alarms, including the Nest Protect, the First Alert OneLink Alexa Safe & Sound, and the OneLink Smart Smoke + Carbon Monoxide, will inform you of the type of alarm triggered and the location of the initiating alarm.

The First Alert SCO7CN and the Kidde 21026043 KN-COSM-BA also have voice alerts, and the First Alert SCO7CN has the bonus of having a programmable location that it will announce when an alarm is triggered so you know precisely which one went off.

A few other models also have integrated lights, though for different purposes. The Nest Protect and the First Alert OneLink Alexa Safe & Sound both have LED ring lights, with the Nest Protect's lighting up automatically as a nightlight based on motion. The First Alert OneLink Alexa Safe & Sound will light up based on ambient light and gives you the option to customize the color.

Conclusion

Hopefully, you have found this review helpful and informative for picking the next smoke detector for your home, regardless of if you are looking for a bare-bones budget option or a deluxe model with smart features. Whether you have a hardwired system or need a battery-powered model, we sincerely hope that one of these products is the perfect match for your needs and budget. Additionally, you should check any local regulations and the guidance by the NFPA to ensure that whatever system you choose is in full compliance for maximum safety and peace of mind.