8 Best Sleep Sacks for Babies, According to Parents

In a nutshell:

Based on feedback from parents in The Bump community and advice from two pediatricians and a pediatric sleep consultant, we chose the HALO Wearable Blanket 100% Cotton as the overall best baby sleep sack. In particular, it stood out because of its roomy, hip-healthy shape, the versatile 0.5 TOG rating that’s suitable for year-round use and the parent-approved two-way zippers.

It’s natural to want to wrap baby up for bed, but putting a blanket in an infant’s crib before their first birthday is a big safety no-no. However, that doesn’t mean your little one has to be cold at night or during naps. A sleep sack is a safe alternative to loose bedding. Similar to (but not the same as) a swaddle, a sleep sack safely restricts baby’s legs (and sometimes arms) to keep them in a cozy cocoon all night long.

Better yet, these wearable blankets come in a variety of seasonal fabrics and fun patterns. Not sure what to look for? Here, discover the best baby sleep sacks according to The Bump community, plus find a breakdown of the different options on the market.

How We Chose the Best Sleep Sacks for Babies

To streamline your search for the best baby sleep sacks, we conducted extensive research so you don’t have to spend hours scrolling through online retailers. When creating this article:

• We reached out to parents in The Bump community and asked them what wearable blankets they’ve used with their little ones. We took note of specific brands and styles they liked and disliked. We also checked what was being said about sleep sacks for babies in The Bump forums.
• We interviewed two pediatricians and a pediatric sleep consultant to better understand what to look for in a baby sleep sack, as well as safety measures to keep in mind when using one.
• We consulted safety guidelines from the American Academy of Pediatrics (AAP) outlining safe sleep practices and swaddling advice for parents.
• To understand how these wearable blankets have worked for various families, we conducted exhaustive market research, scouring forums and message boards and reading user reviews.
• We looked at the most popular infant sleep sacks on the market and considered several factors—like sizing, material, diaper access and TOG rating—when choosing which options to feature in our article.

Editorial integrity is at the heart of everything we publish. Read about how The Bump develops and reviews all articles, including product reviews.

Best Sleep Sacks for Babies

*Note: Some names have been changed due to privacy requests.

What is a Sleep Sack?

A sleep sack is essentially a wearable blanket for baby. Sleep sacks are great for newborns who fight the swaddle and older babies who have graduated beyond the burrito stage. Moreover, wearable blankets can help regulate baby’s temperature and prevent overheating.

Are sleep sacks safe?

According to the AAP, “infant sleep clothing, such as layers of clothing or a wearable blanket or sleep sack, is preferred over blankets and other coverings to keep a baby warm.” The organization reminds parents that baby should be placed in a sleep space free of any loose bedding or soft objects. Blankets can pose a suffocation hazard and increase the risk of SIDS. Once baby starts to show signs of rolling over, parents should stop using sleep sacks that compress the arms, chest and body. However, “sleep sacks that do not swaddle and allow the baby to move freely can be used as long as you want,” states the AAP.

When picking out a sleep sack for your little one, Jillian Thistel—a certified pediatric sleep consultant and founder of Twinkling Stars Pediatric Sleep Consulting in Ontario, Canada—reminds parents to make sure the wearable blanket fits baby comfortably. It shouldn’t be “too big or loose (which can put little ones at risk of suffocation),” she explains. Likewise, the sleep sack should be lightweight to reduce the risk of overheating and SIDS, adds Loretta Cody, MD, a board-certified pediatrician based out of Connecticut.

Are weighted sleep sacks safe?

While the majority of sleep sacks are safe, you should never use a weighted option. Updated sleep safety guidelines from the AAP state that weighted sleep sacks aren’t safe for infants. The AAP explains that weighted swaddles and blankets “can place too much pressure on a baby’s chest and lungs.”

Sleep Sack vs. Swaddle: What’s the Difference?

Sleep sacks and swaddles look similar (and some sleep sacks have swaddling features), but there are a few key differences. Alexis Phillips-Walker, DO, a pediatrician at Memorial Hermann Medical Group Pediatrics in Atascocita, Texas, defines a swaddle as “a type of cloth wrap used to tightly wrap a newborn or young infant. It entails snugly wrapping a baby’s arms and torso to mimic the sensation of being in the womb.” She states that swaddles are believed to prevent the startle reflex. As a result, they can promote better sleep by helping newborns feel secure and assist with body temperature regulation. “Swaddles should be used in younger infants up to three to four months old when they start to roll over,” Phillips-Walker explains.

On the other hand, “sleep sacks are wearable blankets designed for young infants and children,” says Phillips-Walker. Unlike swaddles, sleep sacks for babies and toddlers don’t restrict arm movement. They’re also typically worn over baby’s sleepwear to provide added warmth and comfort without posing the suffocation risk of loose blankets. “Sleep sacks are often used beyond the swaddling stage and are appropriate for babies who can roll over and have more control of their movements,” Phillips-Walker shares.

What To Look For in a Sleep Sack for Babies

Wearable blankets come in all shapes, sizes and materials. To simplify your search, keep an eye out for these key features:

• TOG rating. A TOG rating is a unit of measurement that determines the thermal insulation of a garment. Essentially, the higher the TOG rating, the warmer an item is. For babies and toddlers, you’ll typically find sleepwear with a rating of 0.5 to 3.5. When choosing a sleep sack, check the manufacturer’s guidelines and opt for a TOG rating to suit your particular climate and the temperature of your child’s bedroom. No matter the season, keep in mind: Babies shouldn’t be too bundled or too warm during sleep, advises Thistel.
• Size. “Be sure to look at the size of the sleep sack (including the age, height and weight details),” says Thistel. This way, you can ensure it will fit your child properly and create a safe, comfortable sleep environment for your little one.
• Material. When choosing a baby sleep sack, try to avoid styles made from synthetic materials. Natural fabrics—like cotton, muslin and wool—are breathable, warm and gentle on sensitive skin. All in all, it should be “lightweight, comfortable and breathable,” says Thistel.
• Zippers. Well-designed sleep sacks often feature dual zippers, meaning you can change baby’s diaper without removing the sleep sack entirely. According to parents in The Bump community, two-way zippers are a must-have.
• Also, if your child is slightly older—and prone to attempting daring escapes from the crib—an inverted zipper (or one that runs from top to bottom) is a good option, as it’s harder for kids to unfasten.

Types of baby sleep sacks

The two most common sleep sacks for babies are swaddle-like and sleeveless options. Here are the main differences between them:

• Swaddle-style sleep sacks. This design offers an easy-to-use alternative to classic swaddles, making them great for newborns. This type of wearable blanket constricts baby’s arms, which helps curb the moro reflex (also known as the startle reflex).
• Standard sleep sacks. A standard sleep sack keeps baby’s feet and body safely tucked inside the sleeping bag but leaves their arms free to move during the night. This type is safe to use from infancy through toddlerhood, as it provides babies with increased mobility, thanks to the armholes. Rather than the wrap-around style used for swaddle sacks, these wearable blankets are generally fastened with full-length zippers, which gives you easy access for diaper changes.

About the writer:

Emma O’Regan-Reidy is an editor for The Bump. She specializes in writing e-commerce content and has spent years researching the best baby pajamas and sleepwear. Based on her extensive market knowledge, she aims to create engaging, helpful articles to help both new and seasoned parents pick out the best (and safest) sleepwear for their little ones.

Plus, more from The Bump:

The 10 Best Baby Monitors, Tested by a Mom of Four

The Best Baby Pajamas, According to Parents

10 Best Baby Noise Machines to Soothe Your Little One