The Ultimate Guide to Choosing the Best Zip Sleepsuit for Your Baby
When it comes to dressing your baby for both day and night, few things are as versatile and stress-free as a zip sleepsuit. Quick to fasten, comfortable for your little one, and incredibly handy for nappy changes at 2am, it’s no wonder zip-up sleepsuits are becoming a staple in every modern nursery.
But with so many options—different fabrics, styles, and features—how do you choose the best zip sleepsuit for your baby?
This guide will walk you through exactly what to look for, when to use one, and how to pick the perfect sleepsuit based on your baby's age, sleep habits, and the season.
What Is a Zip Sleepsuit?
A zip sleepsuit (also called a zip-up babygrow or zip-up romper) is a one-piece garment for babies and toddlers that typically covers the body from neck to feet and fastens with a zip instead of poppers or buttons.
Unlike traditional baby pyjamas, zip sleepsuits are designed with convenience in mind:
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No fiddly poppers during nappy changes
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Often made with two-way zips for easier access
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Many feature built-in mittens or footies for added warmth and scratch prevention
At These Tiny Things, our zip sleepsuits are made from a buttery-soft bamboo blend and feature dual zips, fold-over mitts, and OEKO-TEX® certified materials for peace of mind.
Why Choose a Zip Sleepsuit Over Traditional Onesies?
Parents love zip sleepsuits for a reason—several, in fact:
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Speed: Zips are much faster than buttons or poppers, especially during late-night changes.
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Comfort: No hard fasteners pressing against baby’s skin.
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Safety: Fewer small parts or chances of misalignment.
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Functionality: Easier to put on wriggly babies who don’t stay still for long.
What to Look for in a Zip Sleepsuit
1. Two-Way Zip
A two-way zipper means you can unzip from the top or bottom—making nappy changes much easier without exposing baby’s chest or arms.
2. Zipper Guard
Look for a sleepsuit with a zipper cover or chin guard to protect your baby’s skin from being rubbed or scratched by the zip.
3. Breathable, Skin-Safe Fabric
Babies have sensitive skin and can overheat easily. Choose materials like:
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Bamboo: Soft, breathable, moisture-wicking, and ideal for warm climates
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Organic cotton: A good choice for cooler months or layering
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OEKO-TEX® certified: Indicates the fabric is free from harmful chemicals
4. Fold-Over Mittens and Feet
Great for newborns to prevent face scratching and to keep their feet warm without needing socks.
5. A Comfortable Fit
Avoid oversized sleepsuits which can bunch or twist. Make sure there’s room to move but not too much fabric around the neck or face.
Zip Sleepsuits by Season: What’s Best?
While These Tiny Things' zip sleepsuits are made with breathable bamboo that works well year-round, the key to adjusting for seasonal changes lies in what you pair them with—specifically, the sleep sack.
Warm Weather (Spring/Summer):
The zip sleepsuit can be worn on its own during warmer nights thanks to its naturally cooling bamboo fabric. For added comfort, skip the layers and combine it with a lightweight 0.3 TOG sleep sack for safe, breathable sleep.
Cooler Months (Autumn/Winter):
In cooler weather, layer your zip sleepsuit with a 0.5 TOG double-layered sleep sack to provide gentle insulation while maintaining breathability. You can also add a bodysuit underneath if needed, based on the room temperature.
Zip Sleepsuit Sizing Guide (By Age)
|
Age |
Sleepsuit Size |
Notes |
|
0–3 months |
Newborn / 0000 |
Comes with optional fold-over mittens and footies—perfect for warmth and protection |
|
3–6 months |
000 |
Fold-over features still available; roomy design for babies starting to roll |
|
6–12 months |
00 |
More mobility? No problem—footies remain optional, allowing for natural movement |
|
12–24+ months |
0 / 1 |
Designed with durability and stretch in mind; optional footies still included |
Always check the weight and height guidelines on the size label and allow for slight shrinkage with cotton-based fabrics.
Final Thoughts
Zip sleepsuits are one of those rare baby items that combine practicality, comfort, and peace of mind. Whether you’re dressing your newborn for their first night at home or managing a wriggly 9-month-old, the right zip sleepsuit can make daily life that little bit easier.
Explore our ultra-soft, OEKO-TEX® certified zip sleepsuits at These Tiny Things and simplify your baby’s bedtime (and your own).
For more sleepwear tips and mum-approved hacks:
FAQ
Are zip sleepsuits safe for newborns?
Yes, provided they fit well, include a zipper guard, and are made of breathable material. Many parents use zip sleepsuits from birth with no issue.
How many zip sleepsuits do I need?
For newborns: 4–6 is ideal to allow for daily changes and accidents.
For older babies: 3–4 usually works if you do laundry regularly.
Can my baby sleep in a zip sleepsuit overnight?
Absolutely. Zip sleepsuits are designed for overnight comfort, especially when made from temperature-regulating fabrics like bamboo.
