The Best Movement Monitor Review

The Snuza Go attached to the diaper and ready to go!
More parents are considering movement monitors in an attempt to ease fears of Sudden Infant Death Syndrome (SIDS). Movement monitors are different than traditional sound or video monitors as they track baby's breathing or the case of the Owlet Smart Sock 2, baby's oxygen and heart rate. While movement monitors don't claim to prevent SIDS, a reliable one might give parents peace of mind and allow for a better night's sleep. Regardless, practicing safe sleep guidelines with EVERY sleep is the most critical step in reducing the likelihood of SIDS. We urge parents to always put babies to sleep on their back, on their own firm sleep space such as a crib, bassinet, or travel crib with a tight-fitting sheet only. What follows are our favorite movement options and buying advice. Whether you're looking for a simple sensor pad or a wearable, these options are the top of the market.
Review by:
Juliet Spurrier, MD & Wendy Schmitz

Last Updated:
February 7, 2018


Best Overall Movement Monitor

Angelcare AC401

Angelcare AC401 Editors' Choice Award

at Amazon
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Wearable: No | Parent Unit: Dedicated
Sound Monitor
Very reliable
Battery backup
Not very portable
Needs hard surface underneath

The Angelcare AC401 is is a movement and sound monitor, something no other option in the roundup can boast. We like that this sensor pad movement monitor has strong reliability, good range, and impressive sound. This unit works well, has a very budget-friendly price, and an easy to use dedicated parent unit with battery backup so you'll have uninterrupted coverage even if the electricity goes out.

The Angelcare AC403 has replaced the AC401 which is no longer being produced.
The AC401 is no longer being produced and the only option online is the 2 parent unit. We think it can be very handy to have two parent units, however, Angelcare has replaced the AC401 with the Angelcare AC403. This is a similar movement monitor with mattress sensor pads and parent unit. The link in this review will take you to the AC403. We will be purchasing and testing the AC403 for future updates to this review and the Sound Monitor review.

While there is so much to love about this great option, it isn't good for travel, and the sensor pads require a hard surface to function so you'll need to make some modifications to most cribs, and it doesn't work with memory foam or hollow core mattresses. However, Angelcare does offer the Angelcare Wooden Board for Monitors which is designed for use with its movement monitors and provides the hard surface you'll need for proper use. Overall, this unit is a reliable choice with the benefit of a sound monitor that works as well as the movement feature.

Read the Review: Angelcare AC401


Gentle Baby Rousing

Snuza Hero

Best Value Award

List Price
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Wearable: Yes | Parent Unit: None
Vibration stimulates baby to move
Easy to use
No parent unit
Short battery life
Can be uncomfortable to wear

The Snuza Hero SE is a clip style wearable with a unique vibration feature designed to gently rouse baby from a deep sleep, so they move enough to stop the alarm. This monitor is the only option we reviewed designed with this in mind. We like the simplicity of this option and the ability to use it while traveling as it doesn't require any special bedding features.

To ensure you never miss the alarm or crying from your baby's room, you can combine this movement style monitor with a sound or video option. Combining products can give you the most information on what is happening in your baby's room.

This style of wearable can be uncomfortable, and it won't work well if the baby rolls over. There is no parent unit, so if the vibration doesn't rouse baby, then an alarm will go off on the diaper, and you'll need to be close enough to hear it. Some parents found the limited battery life frustrating, while others experienced some false alarms when the clip lost contact with the baby's belly. However, if you travel frequently or want a monitor that stimulates baby into movement, then the Snuza Hero is an excellent choice.

Read the Review: Snuza Hero


Easy to Use Mattress Sensor

Babysense 7

The Babysense 7
at Amazon
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Wearable: No | Parent Unit: None
Easy to use
Simple setup
Nothing to wear
Nursery alarm can cause crying
Not very portable
No parent unit

The Babysense 7 is a sensor pad monitor that goes under the crib mattress. It is easy to use and works well right out of the box with only a little bit of preparation. This monitor is easy to use with a control unit on the front of the crib. The Babysense is a reliable monitor with few false alarms, you don't need to worry about attaching anything to baby's clothes, and it works just as well after your little one learns to roll over, unlike the diaper clip type of wearable.

This monitor can also be purchased with a video monitor for about $20 more. While the appeal of seeing and hearing baby along with being alerted to the lack of movement is appealing, we recommend not purchasing the combination pack as the video monitor emits more EMF (Volts/meter) than the top rated monitors in our video monitor review. Even at a distance of 6 ft from the camera, our EMF reader still reads 3.5 V/m while the average value for the top rated video monitors is closer to 2 V/m at this distance. Consider purchasing a video monitor separately as you will use it for a longer period of time and its quality and lower EMF readings are more important than saving a few bucks.

Like other mattress sensor pad options, the Babysense requires a hard surface under the mattress to work properly, and it is the second most expensive option we reviewed. However, it is a very easy to use unit that works well for babies of all ages.


Budget-Friendly Wearable

Snuza Go

Best Value Award

at Amazon
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Wearable: Yes | Parent Unit: None
Easy to use
Nursery alarm can cause crying
Short battery life
No parent unit
Can be uncomfortable to wear

The Snuza Go is a very budget-friendly wearable that clips to the front of the baby's diaper with a flexible sensor that rests on the infant's abdomen. It is easy to use and travels well for those who want to monitor baby's sleep while away from home. This unit has a simple design that requires no initial setup or crib modification, giving that straight out of the box satisfaction. This option is similar to the Snuza Hero, but it lacks the stimulation feature designed for rousing baby.

Worried about not hearing the alarm on the Snuza Go? Consider pairing this product with a sound monitor to stay connected to what is happening in your baby's room and ensure you always hear the alarm.

The Go has no parent unit, and the alarm can cause unnecessary upset for the baby if you don't hear it right away. Some parents remarked that the battery life is short, and replacements are difficult to find, but the lower price of the Go could offset this potential problem. It isn't a great choice for older babies who can roll or crawl as this can lead to false alarms. Overall, this unit has a reasonable price for a basic product that works well on travel.

Read the Review: Snuza Go


Wearable with Smartphone Alerts

Monbaby Smart Button

The Monbaby Smart Button
at Amazon
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Wearable: Yes | Parent Unit: Smartphone
Easy to wear button
Smartphone collects ongoing data
Alerts parent without disturbing baby
Connectivity issues
Smartphone required
Requires Wi-Fi

The Monbaby Smart Button is a cool wearable button that attaches to most baby clothes with ease. This button is small, good for travel, and more comfortable than the wearable options that clip to the diaper and rest on baby's belly. We like the reasonable price and the smartphone capabilities that help create a useful parent unit, so you aren't reliant on staying close to baby to hear the nursery alarm.

This monitor requires the use of Wi-Fi, and some users report that the app is less than ideal. The monitor itself will be useless if you lose it or accidentally run it through the laundry, which is something a sleep-deprived parent might do. However, if you create a new habit of removing the button when your baby wakes up, and you figure out the user interface on the app this option is a high tech monitor that can keep you informed without disturbing your baby with a loud in nursery alarm.

In our tests for EMF, the Monbaby emitted 2.3 V/m. So, while your baby is wearing the button, they are continuously exposed to 2.3 V/m EMF. This gives us pause. On the upside, the Monbaby alerts you to lack of movement instead of sounding an alarm in your baby's room. However, it does this using more EMF than we are comfortable with. We recommend parents weigh the pros and cons of their particular situation to determine if the EMF emitted by the Monbaby works for their family. The Monbaby EMF is lower than the Owlet Smart Sock 2 (3.5 V/m) but higher than the Snuza wearables (virtually none over ambient EMF). We believe less is more when it comes to EMF and we wouldn't feel comfortable using the Monbaby with our own little ones.

Not Recommended

To provide accurate information, so you can make the best decision for your family, we think it is important to discuss the products we don't recommend, especially if we believe there is a potential health concern driving our recommendation. The Owlet Smart Sock 2 is one of these products due to disappointing EMF test results that were far higher (>6 V/m) than any of the competition and significantly higher than everyday products like cell phones. While each parent must weigh the pros and cons of each product to make the best decision for their baby, we believe the potential risks of EMF exposure is concerning enough that we do not recommend parents use this product.

For more information on EMF and our EMF testing, please see the EMF section below. We believe the Owlet comes with an unnecessary and uncertain risk when it comes to EMF and we would not recommend it to a friend.

Monitors Oxygen and Heart Rate

Owlet Smart Sock 2

The Owlet Smart Sock 2
(3% off)
at Amazon
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Wearable: Yes | Parent Unit: Smartphone
Records heart rate and oxygen saturation levels
Smartphone collects ongoing data
Alerts parent without disturbing baby
Sock doesn't fit all babies
Bluetooth connection between sock and base limits range

The Owlet Smart Sock 2 is a wearable sock that works similarly to a pulse oximeter monitoring oxygen saturation and heart rate. This "sock" monitor connects to an app on your smartphone and keeps you connected to your baby with alerts on your phone. This monitor collects and tracks data and prevents waking the baby with a false alarm in the nursery. The Owlet is not a movement monitor and only tracks oxygen saturation and heart rate, not whether or not your baby is moving in a way that indicates breathing. The Owlet is not a medical device and should not be used to treat, monitor, diagnose, or prevent any kind of medical problems. However, you can use your HSA or FSA pre-tax health saving accounts to purchase this monitor.

The Owlet is expensive with a price more than three times some of the competition, and although they offer financing options, it is still expensive for a monitor that can fall off if baby moves too much. We think the tech gadgetry of this option is interesting and likely addictive, but we worry parents will consider it a medical device when even the company says it shouldn't be used as one.

Always practice safe sleep!
The Owlet is different than other monitors in this review. This monitor doesn't track movement like the other options but instead keeps track of oxygen and heart rate, which makes it feel like a device your pediatrician might prescribe for a sick child. However, Owlet and the FDA stress that this monitor should not be considered a medical device and it is not intended to diagnose, treat, prevent, or monitor any kind of medical problem. No monitor, including this one, should be used in place of basic safe sleeping practices like putting your baby on their back to sleep on a firm mattress using only a tight-fitting sheet with nothing else in the crib.

The Angelcare AC401 is a movement and sound monitor and comes with a variety of cords that parents need to arrange in a specific fashion to avoid a strangulation hazard.
The Angelcare AC401 is a movement and sound monitor and comes with a variety of cords that parents need to arrange in a specific fashion to avoid a strangulation hazard.

Movement Monitor Buying Advice

Movement monitors are considered an essential tool by many parents who hope to protect their child from the dangers of sleep-related death. No one is immune to the fear of SIDS. Regardless of the fact that movement detecting monitors are not approved or endorsed by the FDA or the American Academy of Pediatrics (AAP), most of us consider investing in such a product, if there's even a small chance that it can potentially save our child. While these units are not considered medical equipment nor have they been proven to save lives, they can provide the peace of mind that parents crave. Sure you can see your child on a video monitor, and hear their cry on a sound monitor, but are they breathing? Many parents have spent a few minutes staring at the video monitor looking for any indication of movement to put their mind at ease. You could go in the room and check, but we're pretty sure no one wants to wake a sleeping baby.

SIDs Prevention
For great tips on SIDs prevention and the safest sleep practices for baby, read our article on how to protect your baby written by our founder and pediatrician, Dr. Juliet Spurrier.

With so many parts including a parent unit (not pictured) the AC401 is not the most portable unit in the review.
The Snuza Hero attached to the diaper under a one-piece sleeper. While this helps it stay in place  it muffles the sound  hides the alert lights and makes turning it off and on more difficult.

Types of Movement Monitors

There are two basic types of movement monitors that work on similar principles of monitoring your baby while they sleep. One option is placed under baby's mattress (above left), while the other is something they wear on their diaper or clothing (above right). There are pluses and minus to each and finding the right type for you will depend on how you plan to use it.

The Babysense 7
The Babysense 7

Sensor Pads

The most reliable monitors utilize sensors that are placed under the mattress of the crib. These units are designed to sense the slightest movement, like breathing, and if movement stops they relay the information to the nursery control unit or the parent unit. This type is great for at home use as it requires a hard surface under the mattress for proper functioning and they work well for little ones who can roll or crawl. They aren't compatible with memory foam mattresses and most travel or hotel cribs. The Anglecare AC401 and the Babysense 7 are both sensor pad monitors that go under baby's mattress.

The Snuza Hero
The Owlet Smart Sock 2
The Monbaby button monitor


Wearables can clip onto the baby's diaper, attach to their clothing, or be worn on the foot. Depending on the model they can be as small as a button or as large as a beeper. This style is more prone to false alarms due to the greater likelihood of losing contact with the baby than the sensor pads that go under the mattress. However, wearables may be ideal for travel, as it doesn't require anything special to work, but it isn't as reliable as the sensor pads and may fail or give false alarms. They can also be difficult to attach if your baby is already sleeping or become dislodged if the baby is awake. The Snuza monitors (above left), Owlet Smart Sock 2 (above middle), and the Monbaby Smart Button (above right) are all variations of wearable monitors.

These units will not function properly in a moving car or stroller as they are unable to determine if the movement is truly baby or related to the movement of the vehicle or stroller.

The AC401 is very reliable and the parent unit helps keep you alerted on everything happening in your baby's room.
The AC401 is very reliable and the parent unit helps keep you alerted on everything happening in your baby's room.

Parent Unit

Having a parent unit means you can move further from the baby and still hear the alarm or receive the alert. Some monitors are compatible with smartphones and send an alert to the phone via an app. However, many monitor alarms are only on the sensor itself or the nursery unit which remains in the nursery with the baby. Purchasing a product without a parent unit means you need to stay within hearing distance of the monitor or you'll miss the alarm. Some parent units are also nice in the event of a false alarm, so only you are disturbed, and baby can continue to sleep peacefully unaware. Combining the movement monitor with a sound monitor can mitigate this problem and is a popular solution for many parents, but then you need to purchase and maintain two monitors. The Angelcare AC401 comes with a parent unit that doubles as a sound monitor.

The mattress sensor pads  like the Angelcare AC401 pad shown here  are more reliable overall than the wearable movement monitors.
The mattress sensor pads, like the Angelcare AC401 pad shown here, are more reliable overall than the wearable movement monitors.


False alarms can be a frightening experience and often result in more questions than answers. Their occurrence makes reliability an important consideration and the one thing most parents complain about. We feel the sensor pads are the most reliable products with the lowest risk of the sensor moving or becoming dislodged. Products like the Angelcare AC401 and the Babysense 7 seem to have fewer false alarms than any of the wearable options. The primary cause of false alarms seems to happen when wearable monitors lose contact with baby's body and are unable to sense movement. Contact loss can happen if the sock with Owlet Smart Sock 2 falls off, the button on the Monbaby Smart Button loses contact with baby, or the Snuza products shift away from the baby's belly. As your baby gets older and moves more, the likelihood of a wearable becoming dislodged increases. For this reason, the sensor pads result in fewer false alarms as they encompass the entire mattress and are not reliant on a calm and unmoving baby.

Ease of Use

Parents should consider how difficult the product is to use including the buttons, settings, smartphone interface, and battery changes. The Babysense 7 and the Angelcare AC401 are both single button turn on but have some adjustment settings you'll need to manage at least once. The Snuza Go and Snuza Hero require less initial preparation but can be difficult to attach to a squirmy or sleeping baby resulting in false alarms. Parents also complain that the battery compartment is hard to get into making battery changes a frustrating experience. The Monbaby Smart Button and the Owlet Smart Sock 2 can also be difficult to attach, and the sensor and smartphone can fail to connect.

Alarm Volume

Most of the monitors alert inside the nursery, so they need to be loud enough to wake you from a dead sleep in a different room. This also means they may be so loud they scare your little one which leads to crying as opposed to gentle stimulation to encourage movement or breathing. Depending on the size of your house, where the nursery is in relation to your bedroom and whether or not the monitor has become covered in clothing the alarm may be difficult to hear. Given these variables, we highly recommend the monitors without parent units be paired with a sensitive sound monitor. The Angelcare AC401 has a dedicated parent unit that doubles as a sound monitor, so you are sure to hear the alarm and those that work with a smartphone should be able to alert you as long as you are within range and connected.

Adjustable Sensitivity

The Angelcare AC401 and the Babysense 7 have adjustable sensor pads. The highly sensitive pads can pick up ambient noise and vibration from heating vents, fans, or household appliances. If the pads pick up ambient interference, the monitor will not alarm if the infant stops moving. It is important to test your monitor while using everyday appliances in proximity to the baby's room (specifically fans, air filters, and heaters in baby's room). If the alarm does not function, then the sensor can be adjusted to a lower sensitivity to eliminate interference. The wearable monitors are not affected by low-level ambient vibration and do not have an adjustable sensor, but don't mistake this to mean they are suitable for strollers or car seats… they are not.

Electromagnetic Fields (EMF)

While the jury is still out on the effects of EMF on the human body and on the sensitive growing systems of babies, we believe there is enough evidence that indicates potential harm that parents should consider the EMF (Volts/meter) emitted by all of the products used close to or on their little ones. We believe that a better safe than sorry approach is smart and that parents should make thoughtful and informed decisions when choosing products that emit EMF. With this in mind, we tested each product to determine how much EMF is emitted when it is in use.

The Owlet Smart Sock 2 has a significantly higher level of EMF than all of the movement competition and more than any of the video monitors we tested in our video monitor review. Our EMF meter registered in excess of 6 V/m, the highest the monitor goes, when placed next to the Owlet sock. We are not comfortable with this level of EMF being used right on a baby, which was a higher level of EMF than we measured from a cell phone during a call, and 3x higher than Fitbit fitness monitors emitted (we tested two models, more on this below). In comparison, the wearable Snuza models emitted no EMF (V/m) over the ambient room reading (0.4 V/m). The Owlet was also more than twice as high in EMF than the 2.3 V/m for the Monbaby Smart Button (which is also arguably high in our opinion). The mattress sensor pads from BabySense and Angelcare also emit no EMF over ambient in our tests. In our opinion, this means any of the movement monitors are better for your baby than the Owlet Smart Sock 2 and those that emit no EMF V/m are preferable.
To give you some perspective, we also tested the EMF on a smartphone and some wearable fitness monitors. This way you can see just how the wearable monitors compare to everyday items in your world that you use or keep on your person. We feel parents can relate to this data as concerns over radiation from cell phones and cancer have increased in recent years. Compared to a smartphone with WiFi on and making a call, which we measured at 2.9 V/m at one foot distance, the Owlet was measured at 4.6 V/m at one foot distance — nearly double the smartphone during a call. Even at a mere 1 inch away from the meter, the Fitbit Charge 2 has a reading of 1.34 V/m and the FitBit Blaze is 1.98 V/m, both significantly less than the Owlet Smart Sock 2 (>6 V/m) and the Monbaby Smart Button (2.3 V/m). From our point of view, even though there isn't conclusive data concerning what level/duration of V/m is dangerous, we would not recommend this for the first formative six months (when this kind of product is useful) especially since there are good alternatives available that do not have this issue. Babies are more susceptible to EMF than adults because they are still developing and have thinner skulls. Given this fact, we are disturbed that products for monitoring babies don't have significantly lower EMF on par with adult products.

Our take away? In our opinion, given the concerns and data to support the concept that smartphones should not be used for long periods of time next to your head because of radiation and cancer, we do NOT think it is a good idea to use an EMF emitting product directly on your baby and we recommend any EMF emitting monitors determined to be absolutely necessary be placed as far from little ones as possible for the monitor to still be functional.


Movement monitors are not a medical device, and should not be relied upon to prevent SIDS, or to monitor any other medical condition. They can, however, offer some peace of mind for many parents, and if that helps you get some much-needed rest, who can argue with that? No matter what your final decision in as far as baby monitors go, nothing can replace smart and safe sleeping practices to reduce the risk of SIDs. Babies should always be put to sleep on their back, in their own sleep space with a firm sleep surface and tight-fitting mattress sheet only. No blankets, toys, or bumpers should be used in baby's sleep area. Creating a comfortable sleep environment can also be beneficial by providing adequate airflow with a fan or air filter, never smoking around your baby or in your baby's room, and keeping the room from becoming too hot with a temperature that is comfortable for an adult in lightweight clothing.
Juliet Spurrier, MD & Wendy Schmitz

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