Home & Office
Why you can trust ZDNET : ZDNET independently tests and researches products to bring you our best recommendations and advice. When you buy through our links, we may earn a commission. Our process

'ZDNET Recommends': What exactly does it mean?

ZDNET's recommendations are based on many hours of testing, research, and comparison shopping. We gather data from the best available sources, including vendor and retailer listings as well as other relevant and independent reviews sites. And we pore over customer reviews to find out what matters to real people who already own and use the products and services we’re assessing.

When you click through from our site to a retailer and buy a product or service, we may earn affiliate commissions. This helps support our work, but does not affect what we cover or how, and it does not affect the price you pay. Neither ZDNET nor the author are compensated for these independent reviews. Indeed, we follow strict guidelines that ensure our editorial content is never influenced by advertisers.

ZDNET's editorial team writes on behalf of you, our reader. Our goal is to deliver the most accurate information and the most knowledgeable advice possible in order to help you make smarter buying decisions on tech gear and a wide array of products and services. Our editors thoroughly review and fact-check every article to ensure that our content meets the highest standards. If we have made an error or published misleading information, we will correct or clarify the article. If you see inaccuracies in our content, please report the mistake via this form.


What is the best smart smoke detector and are they worth it?

With the best smart smoke detectors on the market, you can rest assured that you're protected and in the know; especially from any potential Halloween decoration mishaps.
Written by Maria Diaz, Staff Writer
Reviewed by Taylor Clemons
Nest Protect | Best smart smoke detector overall
A Google Nest Protect mounted on a grey wall above a child's bed
Nest Protect
Best smart smoke detector overall
View now View at Amazon
First Alert OneLink Safe & Sound | Best option with built-in speaker
A man in a black sweater installing a First Alert Safe and Sound smoke detector
First Alert OneLink Safe & Sound
Best option with built-in speaker
View now View at Amazon
X-Sense Wi-Fi Smoke Detector | Best budget smart smoke detector
An X-Sense mini Wi-Fi smoke detector and smartphone on a green and yellow background
X-Sense Wi-Fi Smoke Detector
Best budget smart smoke detector
View now View at Amazon

Halloween is the perfect holiday to go all out on spooky decorations, but the last thing you need is a truly scary situation like a fire. House fires can get out of control in a matter of minutes, which means you only have a few seconds to react if your Halloween paper decorations, cornstalks, or hay-bales catch on fire. 

And it only takes a poorly placed candle or hot light bulb to start a fire. So keeping your smoke detectors up-to-date with fresh batteries at 6 months and replacement units at ten years is key to preventing a catastrophe. But taking your smoke detector game to the next level with a smart version plus carbon monoxide monitoring will keep you in the know at the earliest sign of trouble.

Why buy a smart smoke detector

  • Mobile notifications warn you about fire and carbon monoxide (CO) danger even when you're away from home, so you can call for help to arrive sooner. 
  • Smart alarms are interconnected and will alert you to the exact nature and location of any hazard detected in the home.
  • Automatic self-testing and low battery alerts guarantee that you won't miss an emergency because of a dead or defunct detector.
  • Smart detectors can be silenced from your smartphone -- meaning no more standing on a stool and jabbing at the ceiling with a broomstick to end the beeping.

Did you know? Nearly three in five home fire fatalities occur in homes without functioning smoke alarms. A smart smoke detector tests itself and alerts you when the battery is low, so you know it's always working.

Also: The best fire extinguishers: Essential for your home and car

Pros & Cons
  • Multi-purpose detector
  • Battery or hardwired options
  • Automatic self-testing
  • Broad smart capabilities
  • No Alexa or Siri support
More Details

The Nest Protect detects smoke and carbon monoxide, tests itself regularly, sends intelligent alerts, and connects to your entire smart home.

Aside from a smoke detector, it also includes a humidity sensor, which can cut down on false alarms caused by steam; a motion sensor, which activates the Nest's nightlight when you're up and about after dark; and an ambient light detector, which senses when you've turned out the lights and lets Nest know to flash green -- indicating that it has performed its self-check and everything's in working order.

Installation options

The Nest Protect comes in both a hardwired and battery-operated version, making compatible with any home.

Not sure which kind you need? Simply unscrew one of your existing detectors from its mount: If it's connected to the wall with wires, your home has a hardwired system. If not, it's battery operated.

Peace of mind, automatically

The Nest Protect regularly checks its battery (or backup battery, if you have the hardwired version). It also performs routine siren checks every month and will send you a mobile notification if either component isn't working properly. This ensures that your alarm's battery or loudspeaker won't fail when you need it. 

Perfect addition to a Google Home ecosystem

Although the Protect is great as a standalone unit, it's at its best when paired with other Nest devices. 

The family of products is designed to work together in intelligent ways: for instance, if Nest Protect detects an emergency, your Nest Thermostat can be programmed to shut off all heat and forced air systems to prevent the spread of smoke or CO. 

The Nest Protect smart smoke and CO detector only works with Google Assistant, so it doesn't work with others like Amazon Alexa or Apple's Siri. 


A green, glowing ring on your Nest Protect means everything is working correctly. The ring will change colors in an emergency. Image from Nest.com.

Pros & Cons
  • Multi-room music
  • Battery self-checks
  • HomeKit and Alexa compatible
  • Rechargeable batteries
  • Very expensive
  • No self-testing
  • Hardwire only
More Details

The name is a mouthful but the device itself is a worthy competitor for the Nest Protect. With Alexa integration available, the First Alert OneLink Safe & Sound smoke and CO detector also has a built-in speaker, making it almost like having an Echo on your wall or ceiling. It's also hardwired only, unlike the Nest Protect, which gives you the option to buy a battery-powered version.

However, the OneLink Safe & Sound doesn't perform monthly self-tests for the smoke alarm, though it does perform battery checks. 

Siri & Alexa compatible

Aside from being Alexa-enabled, this smart smoke detector is also HomeKit-compatible. And the built-in speaker goes beyond a chirping alert when smoke is detected: you can ask Alexa to play music on it or use AirPlay with your iPhone. 

And since smoke detectors should be in every bedroom and outside bedrooms, you can enjoy multi-room synchronized music playing.

Also: How to stream from your iPhone to your TV

All this aside, the almost $200 price tag is one drawback for First Alert's OneLink Safe & Sound, especially for a device that you're sure to need at least a handful of at home.

Nightlight feature

This smart smoke detector also has a built-in nightlight to light your way through the dark. You can change the colors of the nightlight depending on the time of day, and even use Alexa or HomeKit to set automations for it.

Pros & Cons
  • No monthly fees
  • Budget-friendly
  • No carbon monoxide monitoring
  • No voice controls
  • No speaker or nightlight
More Details

This is only a good option if you're not looking for a unit with carbon monoxide sensor. Although the X-Sense is a wi-fi smoke detector, it does not monitor for carbon monoxide. 

This smart smoke detector is great for someone looking to upgrade their units for a wi-fi-enabled option, especially if you already have separate carbon monoxide monitors. Each one is only $39.99, with a 3-pack going for $107.99 on Amazon.

Smart on a budget

Since you're able to keep tabs on your X-Sense smoke detectors from your smartphone, you'll get notifications any time the alarm is triggered or any status changes, and you're also able to silence the alarm through the mobile app. 

Though this device skips all the bells and whistles like speaker, voice assistants, and nightlight in favor of a lower price, it's available without monthly fees with control and monitoring through the Tuya application. 

Battery-operated only

This unit only comes in a battery-operated format, so no wiring is involved. And it will check the battery status constantly, to alert you when the battery is running low. So no need to run around the house in the middle of the night trying to find the source of a low-battery chirp before the whole house wakes up.

Unfortunately, the X-Sense wifi smoke detector doesn't use your standard 9V or AA batteries; the batteries are replaceable CR123a 3-volt lithium ones, that are slightly more expensive than other standard ones.

What is the best smart smoke detector?

The best smart smoke detector is the Nest Protect by Google. One of the attribute that made it so is the self-testing feature. The National Fire Protection Association recommends everyone check their smoke detectors every month, something the Nest Protect will do for you.

This device also performs automatic battery checks and sends you mobile alerts if the battery needs replacing.

Smart smoke detector


Voice controls

CO monitoring

Google Nest Protect


Google Assistant only


FirstAlert OneLink Safe & Sound


Alexa and Siri


X-Sense mini Wi-Fi smoke detector




Which is the right smart smoke detector for you?

Smart smoke detectors work like traditional ones, using ionization or photoelectric sensors (or a combination of the two) to detect smoke in the air and sounding a loud alarm if there's a fire danger. The difference? Smart smoke detectors are wifi-enabled. 

CO monitoring

It's important to look at the features and determine which ones are important to you. Personally, I feel like both a smoke detector and a carbon monoxide monitor is an absolute must for every home. We have our regular smoke detectors at home, but we also have separate carbon monoxide monitors installed. 

If you already have separate CO monitors at home and want to stick to a budget, the X-Sense wi-fi smoke detectors may be a good replacement option for the units at your home.

Other features

Voice assistance, or lack thereof, is another feature to look at. It's also where Nest Protect falls behind compared to its main competition -- the First Alert OneLink Safe & Sound. The Safe & Sound detector comes with a built-in, Alexa-enabled speaker, which can respond to voice commands, stream music, and perform just about all of Alexa's skills.

That said, the Safe & Sound costs almost $100 more than the Nest Protect, and it doesn't improve on any of a smart detector's key features (like smoke and carbon monoxide detection, mobile alerts, or automatic testing). And since most homes require multiple detectors, you'll end up paying that extra $80-$100 -- the same price as Amazon Echo -- several times over. To maximize smart capabilities and minimize cost, we'd recommend buying a Nest Protect and Amazon Echo separately, rather than opting for the Safe & Sound.

Buy this smart smoke detector...

If you need...

Google Nest Protect

A well-rounded device for detecting smoke and carbon monoxide in your home

FirstAlert OneLink Safe & Sound

A smart smoke and CO detector with a built-in speaker

X-Sense mini Wi-Fi smoke detector

A budget-friendly smoke detector

How did we choose these smart smoke detectors?

When it comes to our own homes and families, safety is undoubtedly the top priority. We chose the best smart smoke detectors that in mind, but we also looked at which smart smoke detectors are the most effective, reliable, and easy to maintain, as well as which add the most benefit to users.

After testing, comparing, and researching, we focused on safety first, then convenience. 

These smart smoke detectors also include carbon monoxide sensors in one device, with the exception of the X-Sense. This feature eliminates the need to check and maintain two separate monitors on a regular basis and giving you the extra peace of mind, which is another important point when choosing one.

Are smart detectors worth it?

Smart smoke and CO detectors can be a big investment. Replacing every unit in an average two-story home can easily cost $600 - $1000. Keep in mind that most states do require interconnected smoke alarms in the home, and the rest will in the near future. So if you're nearing the 10-year replacement period on your current alarms -- and excited about smart tech -- switching to smart detectors puts you ahead of the curve.

If smart tech isn't your thing, traditional hardwired alarms fulfill that requirement for a fraction of the cost.

Do I need a Carbon Monoxide (CO) detector?

Carbon monoxide monitors have grown more popular in recent years with more people learning the dangers of CO poisoning, but are you required to have them in your home?

The truth is that many states have made CO detectors a requirement in new constructions, some in rental units, or depending on the size of the home. It's important to check your state requirements when making changes to smoke and CO detectors, but it's always a great idea to have both in any home.

Often referred to as the silent killer, carbon monoxide poisoning was responsible for 399 non-fire-related deaths in 2017 alone. 

How often do you need to replace smoke and carbon monoxide detectors?

The U.S. Fire Administration recommends replacing your smoke detectors once every 10 years to ensure that all sensors are working properly. Carbon monoxide detectors typically need replacing every five to seven years, according to the manufacturer's instructions. It may be the right time to consider investing in smart detectors if you're approaching those end dates.

How many smart detectors do I need?

The number of smart detectors you need depends on the size and layout of your home. The National Fire Protection Association recommends installing a smoke alarm "inside each bedroom, outside each sleeping area, and on every level of the home, including the basement." CO alarms have similar requirements, so you don't have to worry about installing extra detectors anywhere you wouldn't normally place a smoke alarm. You're not required to replace every device with a smart version, but note that by mixing smart detectors and non-smart detectors, important functions are lost -- like the ability to alert you to the specific room in which smoke has been detected.

How do I choose from hard-wired or battery-operated smart smoke detectors?

Smoke and CO detectors in the home can either be hardwired or battery-powered.

  • Hardwired smoke and CO detectors are wired to your home's electrical circuit. This means all alarms in the house are interconnected -- so when one detects smoke or CO, they all sound. Most states require hardwired smoke detectors in all newly constructed buildings.
  • Battery-powered or "standalone" smoke and CO detectors use a replaceable 9-volt battery. Unless they have wifi or smart capabilities, standalone detectors aren't interconnected -- so they'll only sound in the room where smoke is present. These are generally found in older homes.

The type of detectors you currently have at home will help determine which smart detectors you should get. The Nest Protect comes in both hardwired and battery-operated versions to be installed in any home, for example.

Are there alternatives worth considering?

Editorial standards