The Best Smart Sensors for Alexa, Apple Home, and Google Home (2024)

Eric Chiu substantially rewrote this guide in 2023. He has worked as a consumer-tech journalist for more than a decade, covering devices including smart-home gear and internet hardware.

Smart sensors can work on their own or in combination with other devices. They’re great if you want to solve a particular problem. For instance, you might use a motion sensor to send you an alert if an older family member leaves their room overnight. Or you may use a contact sensor to turn off the HVAC whenever someone leaves the back door or a window open. You could use a temperature sensor to monitor an unconditioned space, for example, or a vacation home with spots that are prone to freezing.

Though smart sensors aren’t especially complicated to use, setting them up requires a bit more legwork compared with installing a smart speaker or smart light bulb, as well as a familiarity with smartphone apps, basic knowledge of (or willingness to learn about) smart-home concepts, and an interest in home automation.

Another consideration is that most smart sensors require the purchase and use of a secondary device, called a hub, that allows them to connect to your Wi-Fi network and the internet. While most hubs support a number of wireless standards and are compatible with a wide range of devices, others may be proprietary to a particular brand. The smart sensors we feature in this guide all work with Zigbee wireless, a standard supported by popular hubs including those for SmartThings as well as several Amazon Echo smart speakers, such as the flagship Echo, the Echo Show 8, and the Echo Studio. Aqara devices work with Zigbee but require the use of Aqara-branded hubs. Before you purchase a sensor, to save money and potential hassle, it’s prudent to consider what devices you may already own or plan to buy, as well as what, if any, hubs you would need to support them.

Many types of smart sensors are available, but for this guide we looked at three categories that have wide appeal: motion, temperature, and contact sensors.

The makers of home security systems sell their own branded sensors as well, but they also require you to stay within their app ecosystem or maintain a subscription. This guide focuses on standalone sensors; check out our best home security system guide if you’re interested in learning more about those competitors.

For this guide we focused on the most popular types of smart-home sensors: motion, temperature, and contact sensors. For the latest update, we revisited our existing top picks and surveyed the current sensor market for new additions.

During our initial product research, we prioritized the following details:

During our initial research, we also weighed factors such as hub requirements, customer service resources, and update support. As noted above, many smart-home sensors need to be connected to a hub, another typically puck-shaped device, in order to connect to your Wi-Fi network—and while some hubs are widely compatible and can support many smart devices, others are proprietary and may work only with devices from a particular brand. (You can also find sensors that don’t require a hub and instead connect via Wi-Fi or Bluetooth, but they generally have worse range and comparatively poor battery life.)

We also prioritized customer service and support resources during our research stage. Though sensors aren’t a big-ticket investment, our top picks are still backed by live customer-service agents, extensive support resources, and regular updates, which help to ensure that your device won’t become outdated prematurely and possibly discontinued.

For this update, we evaluated 31 sensors and tested 16 models in a one-story, 1,000-square-foot home with a detached garage. We installed sensors throughout the home and evaluated factors including ease of installation, performance, battery life, and reliability. Our stress testing for each sensor included the following evaluations:

Compatibility: Amazon Alexa, Google Home, Apple Home, IFTTT

The Aqara Motion Sensor P1 checks all the important boxes for a motion sensor: It’s fast, reliable, affordable, and easy to install. In our testing, the P1 was a breeze to set up, and the sensor’s performance was highly consistent. As part of our testing, we set the P1 above a door frame that was at the end of a 20-foot hallway and created a Routine to send a notification via Alexa when the sensor detected motion; the P1 instantly detected motion up close but also from long range, along the entire hallway.

It gives you installation flexibility. Unlike many competing models we tested, which come with only double-sided tape on the back, this Aqara motion sensor features an adjustable ball-and-socket stand, which gives you far more versatile installation options. You could install the P1 in a corner of a room for maximum coverage, say, or angle it above a door frame to detect when people enter or leave.

Thanks to that stand, combined with the P1’s compact dimensions—its cylindrical body measures only 1.3 inches wide and 1.6 inches tall—you can discreetly mount it on a wall or shelf without taking up excessive space. At around $20, the P1 is low-cost enough that you can reasonably distribute a few throughout a home.

You don’t have to worry about the battery life. One of the P1’s biggest upgrades compared with the previous generation of Aqara motion sensors is an improved strategy for stretching time between battery exchanges. Whereas most sensors run on a single coin battery, the P1’s battery bay stacks two CR2450 coin batteries on top of each other. With that double-battery setup, draining the sensor’s battery power will take a while—in fact, Aqara claims that normal use should result in a five-year battery life for the P1. We’ll keep an eye on it.

Aqara offers great support. The P1 gets over-the-air firmware updates through the Aqara app, and Aqara guarantees at least two years of continued OTA updates after its products reach their end of life.

Flaws but not dealbreakers

It requires an Aqara hub. As with most Aqara devices, you have to purchase an Aqara hub before you can connect the P1 to Amazon Alexa or Apple HomeKit. Aqara sells multiple hubs, ranging from USB sticks to speakers to cameras; during our evaluations, we used the Aqara Hub M2, which can connect to a home network over Ethernet or Wi-Fi. Aqara’s standalone hubs are typically priced between $30 and $60, which puts a slight damper on the P1’s value, but hubs offer much better range for sensors versus a smart-home speaker.

You’ll probably need the Aqara app. In order to pair the P1 with Alexa, you have to install the Aqara app. (Apple Home users can directly pair the P1 via HomeKit.) We didn’t mind the Aqara app, which has great automation and calibration features, but dealing with device-manufacturer apps can be a hassle if you’re trying to keep your app footprint to a minimum.

Privacy and security snapshot

Compatibility: Amazon Alexa (Zigbee-enabled speakers only), Samsung SmartThings, Zigbee hubs

The Centralite Micro Motion Sensor is a budget- and space-friendly sensor. It won’t win any beauty contests, though—it’s just a sturdy white plastic piece that’s roughly the size of a ring box (around 1.75 by 1.1 inches)—and unlike our top motion sensor from Aqara, it lacks Apple Home support.

Still, this Centralite sensor was a strong performer during our testing with near-instant response times, and it promises a two-year battery life.

It’s Zigbee-based, for better or worse. Centralite’s pairing process is more straightforward than that of competitors such as Aqara. Because Centralite doesn’t require that you use a specific hub or app—nearly any Zigbee hub will do—you simply set your smart-home system and sensor in pairing mode and have them pair to each other. (If you’re buying your first hub alongside this Centralite sensor, a starter model such as the current-generation Amazon Echo smart speaker costs $100.) Thanks to the convenient pairing button on the side of this Centralite sensor, we had no difficulties connecting it to our smart-home system; some sensors, in contrast, have their reset button inside or require you to use a tool or pin to trigger them.

Branded hubs do offer some advantages, however, such as sensor-calibration options and the ability to receive updates. Centralite’s no-hub-and-no-app approach keeps things simple, but you sacrifice some functionality in the process.

It gives you versatile mounting options. This Centralite sensor has squared-off sides that allow you to mount it in a corner of a room across two walls to maximize its motion coverage. This design is a nice added touch in comparison with most sensors, which limit their installation options to basic double-sided tape on a single surface.

Privacy and security snapshot

Compatibility: Amazon Alexa (Zigbee-enabled speakers only), Samsung SmartThings, Zigbee hubs

The Centralite Temperature and Humidity Sensor detects temperature quickly and accurately, and its low-profile design makes it easy to hide. It requires the use of a compatible Zigbee-wireless hub, which you may already own if you have a smart speaker.

You can save if you already have a smart hub. This Centralite sensor is pricier than Aqara’s temperature sensor, but if you already have a compatible Zigbee wireless hub—such as an Alexa smart speaker like the flagship Echo, the Echo Show 8, or the Echo Studio, among others—you don’t have to pony up for another. (Aqara’s sensors, in contrast, require one of the various Aqara hub models, which start at a little more than $55.)

If you’re building a smart home from scratch, going with this Centralite sensor is less of a deal. For instance, Aqara’s M2 hub and temperature sensor typically run around $80 total, while this Centralite sensor and an Amazon Echo speaker cost $130.

Installation is flexible. Centralite’s temperature sensor has a boxy white and gray exterior and is roughly the size of a pill bottle. You can opt to mount it with its double-sided tape backing or the included screwable wall mount. We like the additional installation options, which give you more security if you’re installing the sensor in an unconventional indoor spot such as a basem*nt water-heater room or a garage. It isn’t as small as the Aqara temperature sensor, but it’s small enough to easily blend into a living room or bedroom.

Flaws but not dealbreakers

The reset and pairing process is clunky. We didn’t love Centralite’s finicky reset system, which requires you to take apart the sensor and simultaneously hold down a button on the circuit board while reinserting its coin battery. But it’s something you’re likely to do only once.

During our testing, we accidentally cracked the reset button’s housing in the process of resetting the sensor. Centralite’s other sensors have a built-in reset button on the side that doesn’t require you to pop open the sensor—we wish Centralite had done the same with this model.

It lacks real-time temperature monitoring. As part of our testing, we paired this Centralite sensor with an Amazon Echo (4th Gen) and tracked the temperature data through the Alexa app. Though this sensor offers decent temperature monitoring, it took between 30 seconds and one minute for it to relay temperature updates to the Alexa app.

We quickly hit the sensor’s performance ceiling during our stress testing. During our freezer stress test, the sensor’s displayed temperature stalled at room temperature for around seven minutes before nose-diving to 33 degrees. In practice, most homes don’t experience such freezing temperature swings, but this Centralite sensor isn’t a great fit if you need to track an area that needs precise temperature monitoring, such as a greenhouse.

Privacy and security snapshot

Compatibility: Amazon Alexa, Google Home, Apple Home, IFTTT

The Aqara Temperature and Humidity Sensor provides the best combination of performance and unobtrusive size. Its branded-hub requirement and its limited Alexa support caused it to place a close second to Centralite’s sensor in this category, but if those restrictions don’t matter to you, it’s the better choice.

It’s the fastest and smallest sensor we tested. Around the size of a quarter, this Aqara sensor was the most compact temperature sensor we tested, by a wide margin. We had zero issues with the sensor’s battery life, and it can easily hide within a bedroom or living room, without sticking out. This Aqara sensor also provided the closest thing to real-time temperature monitoring during our evaluations and finished our temperature stress test several minutes ahead of competitors, including our top pick from Centralite. During our freezer stress test, this Aqara sensor hit our testing mark in 2 minutes 25 seconds, while competing sensors took three to seven minutes.

Its limited Alexa support may be a hitch. Unlike other Aqara sensors, this one has only token Alexa compatibility, as you can’t create sensor Routines in the Alexa app; you can do so only in the Aqara app or, if you use Apple HomeKit, the Home app. As a result, within the Alexa app, you can check the sensor’s temperature reading, but you can’t do anything with that information. Though it’s possible to work around these limitations by using Aqara’s app or IFTTT, you’re out of luck with this Aqara sensor if you want to keep your smart-home Routines within a single platform.

Privacy and security snapshot

Compatibility: Amazon Alexa, Google Home, Apple HomeKit, IFTTT

The Aqara Door and Window Sensor was the smallest and most responsive door sensor we tested, by a long shot. It takes up the absolute minimum amount of space for a contact sensor without sacrificing responsiveness or value.

It offers phenomenal performance and lifespan. This Aqara sensor took only a split second to go off during our testing, even when we stressed its range by bringing it far away from the hub and into our test house’s driveway. Though its CR1632 battery isn’t massive, Aqara touts a two-year battery life, and over a two-month testing period it hasn’t budged.

While this Aqara sensor supports both HomeKit and Alexa integration, you still have to use the Aqara app first to set up the sensor. The Aqara app also offers solid automation support.

It’s easy to keep out of view. With dimensions of only 1.6 by 0.87 by 0.43 inches and a straightforward white and gray finish, this Aqara sensor can tuck away out of sight almost anywhere. During our testing, we mounted it on a fridge door with an uneven surface on one side, and we created an Alexa Routine that would cause it to send out a notification whenever the door was open for more than 30 seconds. The Routine consistently ran, with zero configuration and no performance problems.

Flaws but not dealbreakers

It requires an Aqara hub. As with other Aqara sensors, to set this one up you need to purchase an Aqara hub and install the Aqara mobile app. If you’re fully investing in the Aqara ecosystem, it’s easier to swallow the price of the additional hardware, but if you’re dipping your toe into smart sensors for the first time it may be a tough ask.

It ranks slightly behind the competition in its sensor-to-sensor range. One of our tests involved measuring how far apart we could place each contact sensor and its secondary magnet before the sensor went off. In this regard, the Aqara sensor came in slightly behind the competition: We measured a maximum distance of around 22 mm for this sensor, in contrast to competitors that hit the 25 mm to 30 mm range. Though that difference is minuscule, this sensor’s somewhat smaller maximum distance could be a problem if you’re trying to install it on surfaces that have a larger gap, such as a cabinet, versus an interior door frame. When we installed this Aqara sensor on our fridge door, we had to adjust the sensor several times to prevent it from sending out false positives, and we eventually nudged it to hang slightly over the door frame’s edge.

Privacy and security snapshot

Compatibility: Amazon Alexa (with Zigbee-enabled Echo speakers), Samsung SmartThings, Zigbee hubs

The Centralite Micro Door Sensor doesn’t have as many bells and whistles as Aqara’s door sensor, but it’s still a great choice to monitor your home’s doors or windows if you already have a compatible smart hub.

Installation is intuitive. As with Centralite’s motion sensor (and unlike with its Temperature and Humidity Sensor), you simply have to press a button on the side of the Micro Door Sensor to put it into pairing mode. Afterward, we found the sensor easy to pair, and it maintained solid responsiveness throughout our testing. You can install this Centralite sensor with double-sided tape or use the included screw-mounted bracket for additional security.

It offers some flexibility in installation. This Centralite model had the widest sensor-detection range among the contact sensors we evaluated, at around 33 mm. That gives you an ample buffer during the installation process—you don’t have to adjust the sensor units to keep them close and ensure that the alert won’t go off prematurely. This sensor’s wider range can also be an advantage if you’re using it in an area that puts a larger distance between the two sensor components, such as a garage door.

But it’s a step behind the Aqara contact sensor in several ways. This Centralite model is no slouch, but it’s slightly bulkier and slower than the Aqara contact sensor—this sensor is roughly a half-inch larger, and it took around a half-second longer to respond to status changes. We’d wager that Centralite’s no-hub installation process is more of a deciding factor for people than the slight performance gap between competing sensors. But if you’re looking for the smallest and fastest door sensor, the Aqara sensor remains slightly ahead of this Centralite sensor.

Privacy and security snapshot

If you have an expansive home and don’t mind a larger sensor: Consider the YoLink YS7804 motion sensor, the YoLink YS8003 temperature sensor, or the YoLink YS7704 door sensor. YoLink’s sensors were highly responsive throughout our testing, and in our measurements we found their advertised quarter-mile range to be accurate: We brought all our sensors to a nearby park to test their maximum range, and YoLink’s models were the only ones able to maintain a clear connection at such a vast distance. They’re an excellent fit if you need sensor coverage across a large property, or in a separate area such as a detached garage.

We decided not to name any of them as picks because they rely on relatively large AAA batteries rather than smaller, button-style batteries and are thus substantially bulkier and liable to stand out more when mounted on a wall or a door frame.

If you need to track temperatures near a window: Get the Meross MS100FHHK. This circular temperature sensor is solar powered, so you can install it in an open room without having to worry about battery replacement. But Meross’s installation and reset process on this model requires you to keep a SIM-card-tray pin tool around to press the sensor’s pinhole-sized button.

If you need to track temperatures in a greenhouse or outdoors: The YoLink YS8005-UC temperature sensor is waterproof with an IP67 rating, so it’s more suitable for tougher conditions than other sensors. It also comes with a handy string loop so you can hang it on an awning or wall hook.

If you’re all-in on Matter: The Aqara Door and Window Sensor P2 features Matter over Thread support, and it’s also the only contact sensor we evaluated that supports Google Home along with Alexa and HomeKit. However, the P2’s setup process can be finicky: To get it working with Alexa, for instance, we had to first set it up using Apple HomeKit.

Matter and Google Home compatibility is equally tricky, as Aqara says that the P2’s Google-platform support has been tested only with the Nest Hub (2nd gen), the Nest Hub Max, and the Nest Wi-Fi Pro. With a width of nearly 3 inches due to its CR123A battery, this sensor is also significantly taller than the competition.

But at the same time, it’s one of the few Aqara sensors that don’t require you to purchase an Aqara hub, which removes a huge price barrier in comparison with competing contact sensors. This Aqara sensor may require a little more setup TLC, but if you don’t mind working through the P2’s quirks and have an existing Matter setup, you can save a lot on this Aqara model versus other contact sensors.

We are planning to test the following smart sensors for a future update to this guide:

Aqara has released the $130 Smart Hub M3, which the company is billing as an all-in-one home base for home automation. In addition to supporting Zigbee, WiFi and Bluetooth devices it is also Matter and Thread compatible; it also has an infrared transmitter (for devices that use remote controls like Mini-Split units). Aqara says compatibility is limited for third-party devices but the company plans to extend it. We plan to test it soon.

This article was edited by Jon Chase and Grant Clauser.