At first glance, there’s nothing that reads particularly high-tech about the Snoo Smart Sleeper. It looks like a sleek and stylish bassinet, with white mesh walls anchored by a wooden base and chrome legs that give off a vaguely Scandinavian vibe.
But beneath that serene exterior, there’s a lot going on. The bassinet — which has to be plugged in to work and pairs with an app — is outfitted with a microphone and sensors that allow it to tell (via sound and motion clues) whether your baby is awake and in need of soothing. The bassinet responds accordingly with automated swaying and shushing, coaxing the baby to sleep and ultimately allowing parents to get more rest during the bleary, exhausted first months of newborn life.
When the Snoo is on and your baby is calm, it plays a quiet stream of white noise and gently sways the baby from side to side. If your baby fusses or cries, the level of swaying and shushing will gradually increase in intensity, moving up to the fourth and final level if the baby is not soothed by the milder settings. (You have the option to intervene and decrease the speed at any time during this process, if you think it’s too much.)
If the highest level doesn’t quiet and soothe your baby within a designated period of time, the Snoo stops moving entirely and notifies you via its app to attend to your baby. Basically, it’s tagging you as a parent to do a diaper check, get a bottle ready, or figure out whatever else it is that your baby needs.
The concept behind the Snoo is well established. Its designer, pediatrician Harvey Karp, popularized a method of calming babies, called the 5 S’s, in his 2002 book The Happiest Baby on the Block. Caregivers have long embraced and implemented the S’s (swaddling, shushing, swinging, sucking, and holding a baby in a side or stomach position). But the Snoo does a lot of that work for you, enabling an infant to sleep longer and more deeply with less parental intervention.
It’s not like humans are totally forgotten in the process: The Snoo’s features are designed to mimic the relaxing sounds and motions of the womb. The idea is that a baby feels comforted by the familiar during the so-called fourth trimester — a time when the outside world is an unfamiliar and unsettling place. That’s when it works as promised, of course.
The Snoo’s app is easy to use. You can also activate the Snoo’s sound and motion without Wi-Fi or the app, by pressing a button on the front of the bassinet that takes you through the various motion levels. Most people don’t do this because the app is so convenient. But if you have unreliable Wi-Fi, or you find yourself suddenly without it, the Snoo will still be functional. (You do, however, need to plug it into an electrical outlet.)
The decibel range of the bassinet’s white noise varies according to the different levels. The all-night baseline sound — which mimics the womb’s soothing rumble, according to a company spokesperson — comes in at 65 to 70 decibels, whereas Level Four, the highest level, is about 84 decibels. “That sound cannot last, [since the] Snoo automatically stops if a baby crying continues for more than 3 minutes,” the spokesperson told me.
For context: The sound of normal conversation is in the 60 decibel range. Prolonged exposure to noise over 70 decibels could have a cumulative effect. Speak to your pediatrician or health provider if you have concerns.
At 38 pounds, the Snoo is heavy to move, but it’s easy to assemble without tools — it took me only three minutes — and it has a compact footprint of 35¾ by 19 inches.
The bassinet comes with an organic cotton sheet and a starter pack of three Snoo Sleep Sacks in sizes small, medium, and large — proprietary swaddles you zip your baby into and then hook onto two plastic clips affixed to the bassinet’s base. (The device doesn’t turn on unless the baby is securely fastened in; so if a baby doesn’t like being swaddled, the Snoo’s features aren’t of any use.) By attaching the swaddle to the mattress clips, you are effectively immobilizing your child on their back within the bassinet.
The cover of the mattress is water-resistant, and the mattress and mesh can be spot-cleaned with a mild soap or detergent. Unlike some of the other baby bassinets we recommend in our guide to the best bassinets and bedside sleepers, the Snoo has no built-in storage.
The company recommends the Snoo be used until a baby is 6 months old, until they can get up on their hands and knees, or until they hit the Snoo’s 25-pound weight limit — whatever comes first (most babies still weigh less than 25 pounds at 6 months).
When considering a Snoo, you should also factor in the cost of purchasing additional Snoo Sleep Sacks (which come in different sizes), if you want to have extras. We’ve found that it’s usually possible to find them for much cheaper — both new and used — in online marketplace sites than it is to purchase them directly from Happiest Baby.
Happiest Baby, which makes the Snoo, offers two subscription options for the app.
The basic version is available to everyone free of charge; it includes the ability to control the Snoo’s speed and sound, and to receive alerts if the baby needs attention.
Along with the functions of the basic app, the premium version lets you track your baby’s sleeping and eating patterns over time. It also has some advanced settings for motion and sounds, and more. The premium version is free for nine months for those who buy the Snoo directly from the company or an authorized seller; those who rent it get the premium membership for the length of the rental plus one extra month. For people who buy their Snoo secondhand, borrow from a friend, or want to extend the membership beyond nine months, it costs $20 a month.
A newly purchased Snoo comes with a limited one-year warranty, which applies only to the original buyer.
