Your baby’s wellbeing is Happiest Baby’s #1 priority. And we know that it’s your top priority, too! So, when parents have questions about SNOO before they welcome the smart sleeper into their family, we get it! SNOO is unlike any other baby product. It’s natural to have questions, like: Is SNOO bad for babies? Does SNOO create bad habits? Or: Is SNOO bad for development? Fortunately, parents can rest easy knowing that SNOO was created by renowned pediatrician Dr. Harvey Karp, who has devoted his entire medical career to helping babies and their parents. What that means is, you can trust that SNOO was designed with your baby’s health, safety, and development top of mind. SNOO is so trusted, in fact, that over 150 hospitals all over the world place their tiniest patients in SNOO. Here, we set the record straight on some misguided SNOO criticism.

Is SNOO bad for development?

No! SNOO critics have incorrectly speculated that SNOO’s secure swaddling—which can be used for up to six months—hinders a baby’s movement in a way that may cause developmental delays. This is false. Not a single study shows that swaddling for up to 6 months delays baby’s development. In fact, research on prolonged swaddling for 6 to 12 months among Mongolian and Native American babies, found no developmental delays. Swaddling has nothing to do with your little one’s development. What does? Tummy time. According to 2020 research, tummy time is positively linked to gross motor development, total development, plus the ability to crawl and roll. And that’s likely why the American Academy of Pediatrics (AAP) encourages parents to practice tummy time with their little one from the get-go. (Learn more about the importance of tummy time.)

Is SNOO bad for sleep training?

No, SNOO is not bad for sleep training your baby! On the contrary, SNOO can aid sleep training. SNOO’s familiar womb-like sensations help babies drift easily from one sleep cycle to the next, often without fully waking up. But if they do wake and fuss, SNOO waits a few additional seconds before increasing to the next level. This short delay gives your baby an opportunity to begin to learn to self-soothe and to practice falling asleep on their own. And, by responding quickly to cries, SNOO may also help build a baby’s sense of trust (what doctors call “attachment”). This, in turn, builds confidence to fall asleep independently. Usually, by 2 to 3 months SNOO babies can sleep 7 to 10 hours straight. And, by 5 to 6 months, they’re such solid sleepers they no longer need swaddling or motion…and can easily be weaned from SNOO. (Here’s how to transition Baby from SNOO to a crib.)

Does SNOO cause “flat head”?

SNOO is no more likely to cause flat head syndrome (aka positional plagiocephaly) than any other crib or bassinet. That’s because “flat head” is not due to your baby’s sleep space, but their sleep position…specifically, back-sleeping, which is the number one sleep recommendation by the AAP. The organization notes that the rise in flat head syndrome directly correlates with the “Back to Sleep” campaign in the 1990s, which was launched to decrease the incidence of SIDS. If your little one has a preferred head position while snoozing, regularly rotate their bassinet. This will cause your bub to naturally turn toward light or objects in different positions, which’ll lessen the pressure on one spot on their head. Beyond back-sleeping, other flat head risk factors include being born premature or with torticollis (tight neck muscles) and being a twin or triplet. (Being cramped with others in the womb can alter head shape.) Not enough tummy time can also up a baby’s risk for flat head syndrome.

Does SNOO hinder bonding?

No! Think about it this way: Does having Grandma or Grandpa help with the baby hinder your bonding? What about if you enlist a night nurse or postpartum doula? Will their extra set of hands dampen the connection you have to your newborn? Of course, the answer is no! In the same way, the support that SNOO offers parents and the soothing it offers babies does not interfere with your bond. In fact, a 2019 study in the journal PLOS ONE found that the magical mix of rocking, swaddling, and using white noise “evoked an immediate calming response” whether parents used SNOO or soothed their infants themselves. 

Is it neglectful to use SNOO?

Not at all. The award-winning SNOO offers your little one a low level of rocking and shushing, giving them a bit of help getting to sleep and back to sleep if they awaken. If your baby fusses more, SNOO bumps up the help until your baby’s fussing stops. But if your little one continues to cry, SNOO’s sound and motion will cease, and you’ll receive an app notification indicating to you that your baby likely needs a change, a feed, or extra comfort.

Is it “cheating” to use SNOO?

No—there is no “cheating” in raising a baby! In an ideal world, all new parents would have infinite time and energy—and family help—to ensure their newborns were always lovingly rocked, cuddled, and held. But the truth is, extended families are no longer around to help soothe babies and allow exhausted parents time to rest like they were centuries ago. Much of that village has vanished, leaving a generation of parents desperate for new solutions to help them get the help and the sleep they need to stay healthy and happy. That’s what SNOO does. SNOO uses age-old comforting cues—shushing, swaddling, and swinging—to be a stand-in for parents’ disappearing village. SNOO provides a sweet hug, soft shhhhhing, and continuous swaying that someone in your village would’ve offered while you rested.

Is SNOO’s rocking safe?

Yes! Babies have been rocked to sleep since the dawn of time. Heck, they rock nonstop in the womb! That means your baby was born already accustomed to this soothing sleep cue. But there’s no need to worry about your baby being “hooked” on SNOO’s rocking. Once babies reach about 6 months old, they naturally outgrow the need for rocking to help them sleep, making it quite easy to wean them off motion. (Learn more about how to wean your baby off rocking.)

What kind of rocking is not safe for your baby? Sleeping in an infant swing—or any inclined surface. Here, your baby’s head can flop forward, possibly obstructing their airway, causing suffocation. And if left unrestrained, babies can also roll over and asphyxiate. For safe sleep, babies should always be on their backs, on firm, flat surfaces—like SNOO.

Is SNOO’s white noise safe?

Yes! For some sound perspective, it’s helpful to know that, in the womb, babies hear a constant 24/7, blood-flow sound that’s been measured at 75 to 92 decibels (~90 dB is the level of a hair drier). SNOO’s all-night sound, which mimics the womb’s soothing rumble, comes in at about 57 (the level of a whisper) to roughly 28 decibels (the level of singing a lullaby). When SNOO’s white noise “levels up” with Baby’s hard crying, it never goes over ~85 decibels, which is still significantly less intense than a baby’s own cries that can reach or exceed 100 decibels! Remember, SNOO only gets louder when your baby fusses, and it quickly reduces as your baby calms. So, SNOO is only ever at max volume for approximately 4 minutes. Plus, there are different volume level options in the Happiest Baby App, so if you would like to set the volume to the lowest level, you can. (Learn more about white noise and Baby’s hearing.)

Is it safe to swaddle in SNOO after 3 months?

Yes. SNOO babies can remain safely swaddled until they graduate to the crib for two reasons: First, SNOO Sacks offer growing babies plenty of room to wiggle and bend while safely zipped into their swaddle. (Hip-healthy SNOO Sacks are International Hip Dysplasia approved.) Second, the SNOO swaddle attaches to the bassinet’s special safety clips, keeping babies securely on their backs. (Placing babies to sleep on their back is “the single most effective action that parents and caregivers can take to lower a baby’s risk of SIDS,” according to the National Institutes of Health.)

In general, babies do best when swaddling lasts until they’re 4 to 5 months old, but if your baby is rolling and not in SNOO, it’s time to stop swaddling! When swaddled babies roll to their tummies, they don’t have free hands to push up and liberate their face to breathe, which is very dangerous. Usually, babies begin rolling to the stomach between 4 to 6 months old, but some show signs of rolling as early as 2 months. (Learn more about when to stop swaddling.)

Does SNOO create bad habits?

No. Some critics suggest SNOO creates bad habits by causing babies to become reliant on rocking, white noise, and being swaddled, making it more difficult for them to fall asleep without these womb-like sleep cues. This is not true. Here’s why: good sleep cues create good habits, and SNOO is all about good sleep cues.

Good sleep cues:

  • Help babies fall asleep quickly
  • Help babies stay asleep longer
  • Are easy to use
  • Require little effort on your part
  • Are easy to wean

SNOO has been shown to help babies fall asleep faster and snooze longer. Plus, SNOO is easy peasy to use. So, the big question remains: Is it easy to wean babies from SNOO’s sound, swaddle, and motion? The answer is, yes!

How to Wean From SNOO

  • To taper your little one off white noise, simply lower the volume gradually over a week or two until it’s off. (Though it can be helpful to stick with white noise throughout toddlerhood.)

  • To help ease your baby out of the swaddle, start with arms-out sleeping. Undo the shoulder snaps on one side of your baby’s SNOO Sack, allowing one arm out. After a few nights of successful sleep with one arm free, you can let the other arm out.

  • To wean your baby from rocking, engage Weaning Mode on the Happiest Baby app. (Do this after your little one is snoozing with both arms free.) SNOO will continue to give your sleeping baby soothing sounds—but no motion. The motion only comes back on if your baby cries. At that point, SNOO responds as usual—with motion and sound—until your baby is soothed…and then gradually returns to some sound, but no motion. (The good news: Once babies are 6 months old, they tend to naturally outgrow their desire to rock.)

Is there SNOO research?

Yes! For example, a 2020 study demonstrated that SNOO’s constant womb-like rhythms boost a baby’s sleep by an average of one hour a night. And after two months of use, SNOO increases a baby’s longest continuous period of nighttime sleep from about five hours to almost seven hours. In other words, SNOO buoyed babies’ consolidated, continuous sleep by 40%! Still, other research has found that SNOO’s rocking, swaddling, and white noise combo works just as well as parent soothing to calm fussy babies quickly. Plus, more than 90% of nurses surveyed agree that SNOO reduces infant fussing.

SNOO Reviews

While we’re proud of the strong science behind SNOO and the more than thirty awards SNOO has won, what means the most to us are reviews from real families. SNOO has thousands of 5-star reviews, and so many parents have reached out to share their experiences. (You can read some of those SNOO stories here!)


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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.