When it comes to keeping your baby safe and well-rested, the American Academy of Pediatrics (AAP) recommends infants sleep on their back on a firm, tightly fitting mattress. The mattress should be covered by a fitted sheet with no other bedding or soft objects with care taken to keep them from overheating. To keep them cozy and safe, baby sleep sacks are key.

What are baby sleep sacks?

Baby sleep sacks, or wearable blankets, offer the comfort and warmth of a traditional blanket without the possibility of it ending up over their head or tangled around their body. They're also a great alternative to swaddling for babies who don't like being wrapped up or have transitioned out of it. With access to their hands and a dwindling moro reflex, sleep sacks allow little ones to use their hands as a way to self-regulate. They also can help prevent wiggly babies from getting their legs stuck in the slats of the crib. (Seriously, why do these tiny creatures always end up squished into the corner? There's so much room in there!)

What should you look for in a sleep sack?

According to Rachel Mitchell, Certified Sleep Specialist and founder of My Sweet Sleeper, the fabric, weight and breathability are most important. 100% organic cotton is most versatile across seasons, though fabrics like bamboo, wool and TENCEL are equally great for sensitive baby skin. When you start shopping around you'll also notice something called the TOG rating. TOG (Thermal Overall Grade) is a standardized unit of measurement that calculates how much warmth a textile provides. The higher the rating, the more insulation. The lightest TOG rating for sleep sacks is generally around 0.5 which is perfect for summer sleeping while ratings up to 3.5 would be used for super cold climates or camping.

When it comes to sizing, each brand is different, so be sure to check the measurements. Ideally you babe has room to kick and move more freely but still be somewhat restricted.

Related: Baby Sleep Guides & Schedules

No matter what style you choose, make sure to always check the inside (especially after washing) to be sure there are no loose threads that could get tangled around your baby's toes.

How long do babies use sleep sacks?

Since the AAP does not recommend loose blankets until after one year, you'll want to use a wearable blanket for at least that long. After that, it's really up to you and your toddler. Many brands make styles that fit well into toddlerhood, and if we're being honest, we've depended on them to keep our tot-sized jail breakers in their crib just a little longer. (Don't judge. Every minute of sleep counts.)

We've rounded up some of the coziest baby sleep sacks that get high marks from our sleep expert and mamas alike. From lightweight cotton sleep bags to quilted sleep sacks for chilly winter nights, they may be just the thing to help everyone get a little more sleep. And nothing's better than that.

Best baby sleep sacks

Kyte Baby Sleep Bag

Kyte Baby

$45

Sleep Bag

The oh-so-soft bamboo sleep sacks from Kyte Baby are a favorite among Motherly staff and experts alike. Available in three TOG ratings and two styles (traditional bag and walker), there’s literally one for every season. The breathable designs feature an easy pull dual zipper that makes getting them in and out as easy as possible as well as keeping nighttime diaper changes smooth and fuss-free. Another thing we love? Their sizing structure which takes away the guess work. Each product page has a super handy size chart that helps you choose based on height and weight. There are a ton of gorgeous muted colors which all pair beautifully with their cozy footies!

Halo Sleepsack Wearable Cotton Blanket

Halo

$29.99

SleepSack Wearable Cotton Blanket

The name Halo is practically synonymous with sleep sacks–and for good reason. Their innovative wearable blankets were the first to market in the early 90s, developed by an engineer and father who lost his first baby to SIDS in 1991. He made it his life’s mission to make sure no other families had to suffer such a loss. The result? A product that is–to this day–the #1 choice in hospitals, available in over 1,700 nationwide. At less than $30, the Halo SleepSack is one of our top choices as well. It’s made from 100% cotton with a 0.5 TOG rating, so it’s breathable and cozy–light enough for warm nights or paired with warmer pajamas for chilly ones. For night time changes, an inverted zipper provides easy diaper access. Additionally, the roomy bottom means they’re recognized by the International Hip Dysplasia Institute as “Hip Healthy”.

Aden + Anais Cotton Muslin Sleeping Bag

Aden + Anais

$39.95

Cotton Muslin Sleeping Bag

We have to credit Aden + Anais with introducing us to the best baby fabric of all time–muslin. For almost two decades parents have wrapped their babes in the brand’s gorgeous swaddles and raved about the softness and breathability. The same can be said of their sleeping bags! Made from a single layer of their signature luxe cotton muslin, the 1.0 TOG rated sleep sack offers plenty of temperature regulation and warmth while still being lightweight. Like their swaddles, there are a bunch of stylish patterns to choose from.

Woolino 4 Season Sleeping Bag

Woolino

$99.99

4 Season Baby Sleep Bag

In a word? AH-MAZING. Yes, it’s also the most expensive on our list but hear us out. Pound for pound, it’s actually the cheapest. First of all, this brilliant sleep sack is designed to be used from 2 months to 2 years. (Trust us, we tested!) They won’t outgrow it before you can swap to regular blankets and because it’s made with a silky soft Merino wool lining and organic cotton outer, it’s perfect for any weather. It’s literally the only sleep sack you need. (See? Most cost-effective in the long run!) It also comes with a slit around the bottom, which makes it suitable to be used in a car seat. If you’re traveling at night you can make sure your little one will be nice and cozy in their sleep sack. And, it comes in a ton of awesome prints!

Burt's Bees Baby Wearable Blanket

Burt's Bees Baby

$24.95

Wearable Blanket

With nearly 25K 5-star ratings, Burt’s Bees Wearable Blankets are a fan-favorite to say the least. Like their equally beloved jammies, the sleep sacks are made from soft high-quality 100% organic cotton which is ideal for sensitive skin and makes it easy to layer based on temps. And at just under $25 bucks, they’re one of the best values out there! They’re available in both 0.5 and 1.5 TOG ratings and three sizes along with a stellar selection of prints.

Baby DeeDee Sleep Nest Sleeping Sack

Baby DeeDee

$38

Sleep Nest Sleeping Sack

Chilly nights call for this enviably cozy sleep sack from Baby DeeDee. (Seriously, we want for ourselves.) The quilted style is more like a sleeping bag than a blanket with a 100% cotton exterior and soft interior that keeps them comfy all night long. A 2.5 TOG rating makes this a great option for camping as well. Other features parents love? Shoulder snaps that make it a total cinch to slide sleeping or standing babes inside and a chunky zipper that’s durable and always snag-free.

Simple Joys by Carter's Unisex Baby Sleep Sacks

Simple Joys by Carter's

$29.30

Unisex Baby Sleep Sacks

For simple, affordable no-nonsense basics, Carter’s reigns supreme. Sold as a set of three (which costs less than a single from most brands), these highly-rated sleep sacks are lightweight and small enough for even the tiniest babes. That said, they do run small and only size up to 6-9 months, so they do graduate quickly!

MiliMili Wearable Blanket

MiliMili

$48

Wearable Blanket

MiliMili knocks it out of the park with all their colorful sleep sacks, but the Kona Banana print is our ultimate favorite. The adorable wearable blanket is soft, comfy, and made from high-quality bamboo jersey fabric, which is great for babies’ sensitive skin. There’s a dual zipper, which means it opens at the top and the bottom so zipping up at bedtime or after a diaper change is a cinch! All of MiliMili’s wearable blankets come in light and mid weights as well as four sizes that fit up to 36 months. (Also—as a feel-good bonus: MiliMili is a small business that makes everything in LA and is run by two mamas 💪!)

Magic Merlin Sleepsuit

Baby Merlin

$39.95

Baby Merlin's Magic Sleepsuit

If your baby’s outgrown the swaddle but not quite ready to transition to a traditional sleep sack, the Magic Merlin is the perfect solution for that in-between stage. Developed by a pediatric physical therapist and mom of four, and given almost 20K 5-star ratings from awestruck parents, the “magic” moniker is well-deserved. The suit allows your baby to have hands and feet out, but thanks to a snug fit in the arms, legs and belly it offers more security (and fewer reflex-induced wake-ups) than loose styles. It’s made with multiple soft cotton layers, features a double zipper for easy on and off and comes in two sizes for babies up to nine months (or when the can roll over.)

Note that for safety it should only be used with babies who sleep exclusively on their backs.