Researched, not hands-on tested. Product pages checked on both manufacturers’ websites on October 27, 2026 (HALO size chart: October 25, 2026). How we research products.
One is the cotton sack on almost every registry. The other is the wool bag parents call a splurge. If you are weighing HALO vs Woolino sleep sack options, the real question is simple: one merino bag for every season, or a lighter cotton sack plus a warmer one for winter? This page puts both makers’ official specs side by side so you can choose for your baby and your nursery.
More on nights and naps: our baby sleep guides.
Quick answer: HALO or Woolino?
- Both are arms-free, unweighted sleep sacks with a zipper that opens from the bottom for diaper changes.
- HALO (100% cotton, 0.5 TOG) has a Newborn size on its chart, dries on low in the dryer, and has warmer 1.5 TOG styles for cool rooms.
- Woolino (merino wool lining, organic cotton outer, no TOG) is sold as one bag for a 63°F to 75°F room, in one size from about 2 months and 10 lb to 2 years.
HALO vs Woolino: specs side by side
| Spec | HALO SleepSack Wearable Blanket (100% cotton) | Woolino 4 Season Ultimate Baby Sleep Bag |
|---|---|---|
| Fabric | 100% cotton | Merino wool lining, GOTS certified organic cotton outer, no filling |
| Warmth rating | 0.5 TOG | No TOG given |
| Room temperature the maker gives | 75°F to 77°F on HALO’s TOG guide (the product page also says 68°F to 77°F) | 63°F to 75°F (17 to 24°C) |
| Warmer option from the same brand | Yes, 1.5 TOG styles | Not needed according to Woolino; one bag for year-round use |
| Smallest size | Newborn: 19 to 23 in, 5 to 10 lb (on the size chart) | From 10 lb (about 2 months) |
| Sizes up to age 2 | Newborn, Small (to 18 lb), Medium (to 24 lb), Large (to 28 lb), XL (26 to 36 lb, on the size chart) | One baby size: 23 to 35 in, 10 to 32 lb |
| Toddler size | XL on the size chart (26 to 36 lb) | 2 to 4 years: 34 to 42 in, 26 to 42 lb |
| Sizes on the product page we checked | Small, Medium, Large | Baby (2 months to 2 years), Toddler (2 to 4 years) |
| Zipper | Inverted zipper with a zipper cover | Two-way side zipper that opens flat and from the bottom, zipper-pull guards |
| Extras | HALO says it is approved by the International Hip Dysplasia Institute | Underarm snaps for small babies; closable seatbelt slot |
| Certifications the maker names | None found on the page we checked | OEKO-TEX Standard 100, GOTS, Woolmark, Responsible Wool Standard |
| Care | Machine wash cold, gentle; tumble dry low | Wash on low with wool or mild detergent; no-heat tumble dry or air dry |
For all the details of each, read our HALO SleepSack Wearable Blanket review.
And the matching Woolino sleep sack review.
Where they really differ
How you handle the seasons. HALO gives a number: 0.5 TOG for warm rooms, with 1.5 TOG styles for cooler ones. Woolino gives no TOG and sells one bag for a 63°F to 75°F room, with pajamas underneath doing the adjusting. Our sleep sack TOG chart shows what each TOG level covers.
A hot nursery. Woolino’s range stops at 75°F. HALO’s cotton sack is aimed at 75°F to 77°F. If your nursery is often warm, the light cotton sack fits that room better on paper.
The first weeks. HALO’s chart starts at 5 lb with a Newborn size, though not every print comes in it. Woolino starts at 10 lb. For a newborn who is not yet showing signs of rolling, many parents use a swaddle first; see our sleep sack vs swaddle guide.
How many sacks you buy. HALO sizes by weight and length, so you move up through Small, Medium and Large in the first two years. Woolino’s one baby size covers 10 to 32 lb, and the toddler size continues to 42 lb.
Washing. HALO goes in the dryer on low. Woolino needs a gentle wool wash and no-heat drying, and its product page and FAQ give two different maximum wash temperatures (100°F and 85°F), so follow the care label.
Parents in an older Hellobee thread on favorite sleep sacks (November 2017) named both. One liked HALO because it is relatively inexpensive, which mattered for daycare. Another called Woolino a splurge that truly covered three seasons. Those are experiences, not tests.
Pick HALO if…
- you want a sleep sack for a baby under 10 lb;
- your nursery is warm, or you like choosing a TOG for each season;
- you want to wash and tumble dry it like the rest of the baby laundry;
- you need several sacks, for example one for home and one for daycare.
Pick Woolino if…
- your baby is at least 10 lb and your nursery stays between 63°F and 75°F;
- you would rather buy one bag that grows from about 2 months to 2 years;
- you want certified wool and organic cotton and are fine with gentle washing.
Comparing cotton sacks instead? Read HALO vs Burt’s Bees.
For a walking toddler, our guide to the sleep sack for toddlers compares the bigger sizes of several brands.
Safety notes for both (AAP and CPSC)
- Back to sleep for every sleep, on a firm, flat surface, with no blankets, pillows, toys or bumpers in the crib (AAP). See our safe sleep guide.
- The AAP says you can use a wearable blanket if you are worried about your baby getting cold, and that overheating can increase the risk of SIDS: dress your baby in no more than one layer more than you would wear.
- Neither sack is weighted. The AAP advises against weighted sleep sacks, sleepers and swaddles.
- Moving out of a swaddle? The AAP says to stop swaddling when your baby shows signs of trying to roll. Our guide on when to stop swaddling walks through it.
- Woolino’s seatbelt slot does not change car seat advice: the AAP says bulky clothing should not go under the harness straps.
- Recall check, October 27, 2026: we searched CPSC and news and found no recall of the current HALO cotton wearable blanket or of Woolino sleep bags.
- Warning only: HALO SleepSacks with satin flowers (2013), a choking hazard from detachable petals.
- Warning only: HALO Dream Magic Sleepsuits (March 2026), batch codes PO30592, PO30641 and PO30685, because the zipper head can come off. That is a sleepsuit, not the wearable blanket compared here.
- Warning only: Woolino merino footed pajamas (recalled 2017) for failing the federal flammability standard. That notice covers pajamas, not sleep bags.
Frequently asked questions
They are rated differently. The HALO cotton sack is 0.5 TOG, which HALO's guide puts at 75 to 77 degrees F. Woolino gives no TOG and says its bag is for rooms from 63 to 75 degrees F. For a cooler room, HALO sells 1.5 TOG styles; with Woolino you adjust the pajamas underneath.
HALO's size chart lists a Newborn size for 5 to 10 lb, though not every print is sold in it. The Woolino 4 Season Ultimate starts at 10 lb, which Woolino puts at about 2 months. Stop swaddling as soon as your baby shows signs of rolling (AAP).
It depends on your room and how many sacks you would otherwise buy. Woolino sells one baby size for 10 to 32 lb and one bag for 63 to 75 degrees F. HALO sells several sizes and TOG levels, and its cotton sack is meant for warmer rooms. Check the current price of both.
Free printables: get our Safe Sleep Checklist, Feeding & Diaper Log and Hospital Bag Checklist, plus one short tip email a week. Join Babypino Weekly.
Sources
- HALO: Wearable Blanket 100% Cotton TOG 0.5 product page, checked October 27, 2026
- HALO: SleepSack Wearable Blanket size chart, checked October 25, 2026
- Woolino: 4 Season Ultimate Baby Sleep Bag product page, checked October 27, 2026
- Woolino: sleeping bags sizing chart, checked October 26, 2026
- Woolino: FAQs (room range, minimum weight), checked October 26, 2026
- AAP HealthyChildren.org: A Parent’s Guide to Safe Sleep, checked October 27, 2026
- AAP HealthyChildren.org: Swaddling: Is it Safe?, checked October 27, 2026
- AAP HealthyChildren.org: Winter Car Seat Safety Tips, checked October 26, 2026
- CPSC: HALO SleepSacks Wearable Blankets Recalled (2013)
- CPSC: HALO Dream Recalls Magic Sleepsuits Due to Choking Hazard (2026)
- CPSC: Woolino Recalls Children’s Pajamas (recall 18-042)
This page is general information, not medical advice. Product details can change; check the label and each maker’s current instructions. Talk to your pediatrician about your baby’s sleep.