The Best Sleep Sacks to Keep Babies Cozy and Safe All Night

You can't go wrong with the Woolino 4-Season Ultimate Baby Sleep Bag

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Best Sleep Sacks

Verywell / Sabrina Jiang

There is no shortage of baby products that will help keep your little one soothed and (ideally) sleeping through the night, but sleep sacks or wearable blankets are among the best because they help feel your little one feel secure and offer parents a safe way to keep their child warm while they sleep. Designed to be worn year-round, sleep sacks are available in breathable, cozy, and extra-comfy materials.

Reviewed & Approved

Thanks to its breathable fabric, simple design, and two-way zipper for easy diaper changes, the Woolino 4 Season Ultimate Baby Sleep Bag Sack is our top pick. But if you're on a budget, the Simple Joys by Carter's Unisex Babies' Sleepbag is a great choice that you can buy in a multi-pack.

“Ensure your child is wearing the correct size and that the sack is not too small or large, which can lead to rising up to cover the face, or inhibiting full movement,” sleep consultant Aubrie DeBear, PsyD, tells Verywell Family of choosing the right sleep sack. "Check the age and weight specifications of the sleep sack to make sure it's the right fit for your child.”

In our experience, sleep sacks belong on the “must-have” list of baby supplies for all new parents because they keep babies warm while also following the American Academy of Pediatrics safe sleep guidelines, which advise against loose bedding near infants. Instead of a blanket, look for a sleep sack in a fabric that's appropriate for the temperature in your baby's room and with the type of closure (snaps, zippers, even magnets) that is easiest for you to fumble with in the middle of the night. We researched dozens of the most popular sleep sacks from several leading brands with these factors in mind.

Based on our reviews, here are the best sleep sacks available right now.

Best Overall: Woolino 4 Season Ultimate Baby Sleep Sack

4.8
Woolino 4 Season Ultimate Baby Sleep Bag Sack

Courtesy of Amazon

Pros
  • Shoulder snaps for easy removal

  • Two-way zipper make overnight diaper changes a breeze

  • Safe from 2 months until 2 years of age

Cons
  • Expensive

This Woolino sleep sack is our top choice for all seasons because the merino wool inner layer and organic cotton outer layer are designed to keep your baby’s temperature regulated so that it's just as comfortable during the winter months as it is during the summer months. We also like that it has two snaps at each shoulder so you can slip your baby in and out to put it on (rather than over the head) as well as a zipper at the bottom for easy diaper changes.

Finally, this sleep sack has amazing longevity, because it’s safe for babies as young as 2 months old up to 2 years. It is one of the most expensive sleep sacks available, but the simple fact that it will fit your child until they are 2 years old means this is the only sleep sack you need to buy. And since it's machine washable, you really can get away with just having one. (Though keeping a second to have as a spare is never a bad idea, especially for colic-y or spit-up prone infants.)

Material: Merino wool and organic cotton | Age Range: 2 months old to 2 years old | Machine Washable: Yes

Best for Summer: Baby Deedee Sleep Nest Lite Sleeping Bag Sack

baby deedee Sleep Nest Lite Sleeping Bag Sack

Courtesy of Amazon

Pros
  • Reversible zipper

  • Shoulder snaps

Cons
  • Not designed for cold nights

For hot summer nights, this is the best sleep sack for your child. It’s made from lightweight 100 percent cotton so that it gives your baby the comfort of a blanket while still being breathable to avoid overheating.

It has snap shoulders as well as a reverse zipper for easy diaper changes and is available in three different sizes ranging from newborn to three years old. This sleep sack is machine washable and available in several color opinions.

Material: Cotton | Age Range: Newborn to 3 years old | Machine Washable: Yes

Best Budget: Simple Joys by Carter's Unisex Babies' Sleepbag

Carter's Sleep Sacks

Courtesy of Amazon

Pros
  • Safety tab

  • Stylish designs

  • Lightweight

Cons
  • Best for warmer nights (thin)

  • No reversible zipper

  • Sizing runs big

Infants can begin using this sleep sack immediately after birth, so parents and caregivers can skip the swaddle. While the zipper isn’t reversible, there is a safety tab to cover the zipper at the neckline to keep your baby’s chin and neck safe. 

These sleep sacks are made from 100 percent polyester and feel soft against your baby’s skin. If any accidents happen overnight, you can add the sleep sacks to your regular load of laundry, thanks to the sleep sacks’ machine-washable material.

Material: Polyester | Age Range: Newborn to 9 months | Machine Washable: Yes

Best for Moro Reflex: SwaddleMe Original Swaddle 3-Pack

4.7
SwaddleMe Original Swaddle

Courtesy of Amazon

Pros
  • Perfect for newborns

  • Easy to secure

Cons
  • Unsafe after baby starts to roll/2 months old

  • Baby will outgrow it quickly

In early infancy, babies like to be swaddled to help soothe their Moro (or startle) reflex, but since traditional swaddles can be difficult to use, this product is designed as a combination sleep sack and swaddle.

“Another benefit of sleep sacks is to provide babies with a feeling of security by enclosing their feet for a more womb-like environment," DeBear tells us. And the SwaddleMe is very effective in that regard. All you have to do is tuck your baby’s feet into the little pouch and then wrap the wings around their arms and secure them in a tight little swaddle. For diaper checks and changes, simply pull their legs out of the pouch and then pull it back up when you’re done.

Material: Cotton | Age Range: Babies weighing 7 to 14 pounds | Machine Washable: Yes

Best for Winter: HALO Sleepsack Micro-Fleece Wearable Blanket

HALO Sleepsack Micro-Fleece Wearable Blanket

Courtesy of Amazon

Pros
  • Great for cold nights

  • Inverted zipper

Cons
  • Not recommended for babies under 10 pounds

If your home gets cold in the winter months, this is a great sleep sack to invest in because it’s made from thick, soft 100 percent microfleece. The wearable blanket goes over the baby’s shoulders and then stays put with an inverted zipper that’s designed for easy late-night diaper changes.

You can get this machine-washable sleep sack in a variety of colors and sizes to keep your little one warm up until they reach 28 pounds.

Material: Polyester microfleece | Age Range: Newborn to 24 months old | Machine Washable: Yes

Best for Toddlers: HALO Early Walker Sleepsack

HALO Early Walker Sleepsack

Courtesy of Amazon

Pros
  • Great for walkers

  • Budget-friendly

Cons
  • Feet are not covered

This sleep sack’s design is a little different from the rest because it has feet holes so that babies can safely move around before bedtime. Then once they’re asleep, you can cover their toes back up to keep them warm throughout the night.

It’s made from soft microfleece and comes in three sizes for babies between 16 and 36 pounds.

Material: Polyester microfleece | Age Range: 12 months old to 24 months old | Machine Washable: Yes

Best with Sleeves: Hudson Baby Long-Sleeve Sleeping Bag

Hudson Baby Sleep Sacks

Courtesy of Amazon

Pros
  • 100 percent cotton

  • Several sizing options

  • Different patterns/colors


Cons
  • Long sleeves may be too warm for some

  • Zipper difficult to maneuver

For those cold winter nights, check out this sleep sack designed with long sleeves to keep your baby warm all night long. Made from 100 percent cotton, this wearable blanket is soft and can still be worn with a onesie underneath for additional warmth. 

The sleep sack is available in sizes from newborn and up to 24 months, so your little one is sure to find the right size to keep them comfortable. We also love that this sleep sack is machine-washable for easy cleaning, and it's available in a variety of different patterns and colors for fun styling.

Material: Cotton | Age Range: Newborn and up to 24 months | Machine Washable: Yes

Best for Newborns: HALO Sleepsack 3-Way Adjustable Baby Swaddle

HALO Sleepsack 3-Way Adjustable Baby Swaddle

Courtesy of Amazon

Pros
  • User-friendly

  • Budget-friendly

Cons
  • Not recommended for preemies

  • Not recommended for babies after they can roll/2 months old

Babies as little as 6 pounds (and 19 inches long) can safely use this sleep sack, which is designed to work as a swaddle and, later, a transitional sleep sack. It goes over the baby’s shoulders and has an inverted zipper down the front to secure it in place. Then, to swaddle your newborn, you just wrap the wings around their arms and secure them with the velcro tabs.

”If your child is able to roll, you always want to ensure that they have the use of their arms in any transitional swaddle or sleep sack," DeBear says. If you're using this Halo, that's when you can leave your baby's arms free and simply wrap the wings around their torso instead, still giving them the tight secure feeling of a swaddle. This sleep sack is made from 100 percent cotton muslin and is safe for the washer and dryer.

Material: Cotton muslin | Age Range: Newborn to 18 pounds | Machine Washable: Yes

Best Style: Copper Pearl Sleep Bag

Copper Pearl Sleep Bag

Courtesy of Amazon

Pros
  • Tag-free neck

  • Three layers 

  • Top-to-bottom zipper

Cons
  • Zipper difficult to maneuver

  • Fabric can fade or pill over time

Three layers make up this sleep sack’s polyester and rayon blend, making for a comfortable night’s rest for your baby. With just enough stretch in the material, the sack allows infants to sleep in any (safe) position. Babies can begin using this sleep sack safely immediately after birth, which is convenient for parents and caregivers who have trouble swaddling.

It has a top-to-bottom zipper to make those middle-of-the-night diaper changes just a little bit easier. Plus, we love the tag-free neckline, so your baby doesn’t feel any scratches.

Material: Polyester and rayon | Age Range: Newborn to 12 months | Machine Washable: Yes

Best Organic: Burt's Bees Baby Beekeeper Wearable Blanket

Burt's Bees Baby Baby Beekeeper blanket

Courtesy of Buy Buy Baby

Pros
  • Eco-friendly material

  • Lightweight

Cons
  • Not recommended for cold nights

Made from 100 percent organic cotton, this sleep sack is available in three sizes and various colors. It fits over the baby’s shoulders and has an inverted zipper down the front to keep the blanket in place while also allowing for easy diaper changes at night. This sleep sack is super soft, should not irritate the skin, and is machine washable.

Material: Organic cotton | Age Range: Not Listed | Machine Washable: Yes

Best for Preemies: Mama Cheetah Adjustable Swaddle Blanket Wraps

Mama Cheetah Adjustable Swaddle Blanket Wraps

Courtesy of Mama Cheetah

Pros
  • Adjustable design

  • Preemie-friendly

Cons
  • Not recommended for babies above 7 pounds

For the teeniest babies, this sleep sack and swaddle combo is safe for preemies up to 7 pounds. It’s made from lightweight 100 percent organic cotton that is perfect for keeping your baby warm but with enough breathability to prevent overheating.

To use it, tuck your baby’s feet into the little pouch and then simply wrap the wings around your baby’s arms and use the Velcro straps to secure it. For late-night diaper checks and changes, you can simply untuck your baby’s feet without having to undo their swaddled arms.

Material: Organic cotton | Age Range: Preemies (no babies above 7 pounds) | Machine Washable: Yes

Best Breathable: KYTE BABY Unisex Bamboo Rayon Sleeping Bag

Kyte Baby Sleep Bag

Courtesy of Amazon

Pros
  • Silky smooth fabric

  • Three thermal resistances

Cons
  • Costly

  • Hand-wash only

Available in several colors and in sizes safe for babies from birth up to 3 years old, this sleep sack is made from super soft bamboo, with a hint of spandex, so it is cozy, warm, and breathable. It goes on over the baby’s shoulders and has a diagonal double zipper that keeps the blanket in place but also allows for easy access for diaper changes.

While it is hand-wash only, this sleep sack is an especially excellent choice for babies with sensitive skin.

Material: Bamboo rayon | Age Range: Newborn to 3 years old | Machine Washable: No

Final Verdict

The Woolino 4 Season Ultimate Baby Sleep Bag Sack (view at Amazon) ranks highest on our list because of its breathable fabric that will keep your little one warm in cool months and cool in warm months. Its simple design makes overnight diaper changes easy.

If you're looking to stock your little one's drawer with multiple sleep sacks, the Simple Joys by Carter's Unisex Babies' Sleepbag (view at Amazon) comes in packs of three. It features a safety tab to keep the zipper tucked away from your baby's face so it won't interfere with their sleep.

How We Rated the Sleep Sacks

4.8 to 5 stars: These are the best sleep sacks we reviewed. We recommend them without reservation.

4.5 to 4.7 stars: These sleep sacks are excellent—they might have minor flaws, but we still recommend them.

4.0 to 4.5 stars: We think these are great sleep sacks, but others are better.

3.5 to 3.9 stars: These sleep sacks are just average.

3.4 and below: We don't recommend sleep sacks with this rating; you won't find any on our list.

How We Selected the Best Sleep Sacks

We chose the best sleep sacks by researching reviews from customers and competitors, and we studied the features of more than 30 products on the market. We considered price, design, features, ease of cleaning, material, and any height and weight limitations when deciding our picks. We also spoke to sleep consultant Aubrie DeBear, PsyD, for additional insight and any product recommendations.

What to Look for When Buying a Sleep Sack

Safety

Ensure the sleep sack is the right size for your baby before purchasing it. Look at both the age and weight range to find the best fit. Also, DeBear notes that parents should make sure the sleep sack’s zipper is high quality because if it comes undone in the night, it could pose a suffocation risk

Design

There are several different sleep sack designs to choose from based on your child’s age, size, and mobility. Keep your child’s abilities in mind when choosing either: a swaddle sleep sack that keeps babies' arms wrapped tight, a transitional sleep sack that can go from swaddle to sack as babies grow, standard sleep sack that covers the body while keeping arms free, or an early walker sleep sack that lets babies' feet poke out of the bottom. 

Materials

Sleep sacks come in a variety of materials. They include light and breezy cotton muslin, eco-friendly bamboo rayon and organic cotton, polyester blends that are often easier to care for, and the warmest polyester microfleece.

Obviously, you don’t want to purchase a microfleece sleep sack in the middle of the summer, and you may want to avoid a sleep sack that isn’t safe for the washer or dryer if you're not up for hand-washing, so look closely at how the product is made before purchasing.

Dr. DeBear also suggests considering the climate where you live and the temperature you generally keep your home at to help you decide which material is best for your child.

Frequently Asked Questions

  • Are sleep sacks safe?

    Sleep sacks, or wearable blankets, are safe for babies and are a great way to keep a baby warm as long as they are appropriately sized. Sleep consultant Dr. Aubrie DeBear, PsyD., tells Verywell Family that parents should “ensure your child is wearing the correct size and that the sack is not too small or large, which can lead to rising up to cover the face, or inhibiting full movement.” To do this, she says parents should “check the age and weight specifications of the sleep sack to make sure it's the right fit for your child.”

    In order to create a safe sleeping environment and reduce the risk of SIDS, parents should follow the Safe Sleep Guidelines from the American Academy of Pediatrics (AAP). Babies should sleep in their own crib with a firm mattress free of soft objects and loose bedding like blankets, pillows, toys, or anything else that could cause suffocation. Additionally, it is important to note that the AAP strictly advises against the use of weighted sleep sacks or blankets for babies. 

  • When do babies start wearing sleep sacks?

    Appropriately sized sleep sacks are safe for a baby to use as soon as they’re born. However, because of the startle reflex, many newborns like to be (and sleep better) swaddled, so you will likely want to consider a swaddle sleep sack that has flaps with Velcro, which can be wrapped around the baby’s arms.

    If your baby starts to break out of the swaddle or obviously wants their arms free, many of these sleep sacks allow you to wrap the flaps around their torso, so their arms are free. But they’re still getting the feeling of light compression to help soothe them. 

  • What is the difference between a sleep sack and a swaddle?

    A swaddle is a large piece of cloth cut in the shape of a square that is folded and wrapped snugly around a newborn (kind of like a burrito) to soothe their startle reflex. A sleep sack is a loose-fitting wearable blanket that goes over the baby’s shoulders, keeping their arms free, and zips up to cover the feet and to ensure the blanket stays in place so that it does not pose a suffocation risk.

    Some sleep sacks are designed to also serve as swaddles and/or as transitional blankets as the baby moves from a snug swaddle to a roomier sleep sack.

Why Trust Verywell Family

Ashley Ziegler is a full-time parenting writer and mom to a 2-year-old and a 4-year-old. She has personal experience in researching and purchasing a variety of children’s products, including sleep sacks. Key considerations she used when selecting these recommendations include expert advice, age appropriateness, and user reviews.

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Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Academy of Pediatrics. Safe Sleep: Recommendations.