Here is a truth nobody tells you before you have a baby: you will develop extremely strong opinions about how a onesie fastens shut.
Before parenthood, a button was a button. A zip was a zip. You never once stood in a shop thinking, "But will this snap configuration work in semi-darkness while a small human tries to alligator-roll out of my arms?"
Welcome to the new you. The you who cares deeply about closures.
This guide breaks down every fastening type you'll encounter on baby clothes — the good, the bad, and the "who designed this, a person who has clearly never held a baby."
Buttons
Charming but impracticalBeautiful on a shelf. Nightmarish in practice.
The classic. Adorable wooden or shell buttons looking like something from a Peter Rabbit illustration. In a well-lit, calm, fully-rested scenario, buttons are lovely. In every other scenario — which is to say, actual parenthood — they are an exercise in frustration.
Buttons require two hands, good lighting, and a baby who stays still. You have, on average, none of these things.
- Undeniably cute — the aesthetic is real
- No metal or plastic against skin
- Durable — buttons rarely break
- Easy to replace if one comes off
- Slowest closure type by far
- Requires two hands and good dexterity
- Impossible to align in low light
- Choking hazard if a button detaches
- Easily mis-buttoned (one off = redo all)
Press Studs (Snaps)
The reliable workhorseThe industry standard. Not exciting, but not terrible.
Press studs are the most common closure on baby clothes worldwide. Press together, pull apart. Simple concept, generally reliable execution.
The problem isn't any single snap — it's the quantity. A typical onesie has eight to twelve snaps. In the dark, you will absolutely snap the wrong pairs together.
- Widely available on almost all baby brands
- Faster than buttons
- Can be done with one hand (with practice)
- Secure — snaps don't accidentally open
- Affordable to manufacture
- Mis-snapping is almost guaranteed in low light
- Metal/plastic against skin can irritate
- Still slower than a zip
- Audible "click" can wake a drowsy baby
- Snaps can weaken over many washes
One-Way Zip
Fast, but half the storyA big upgrade from snaps. Not quite the full solution.
A single zip running from neck to ankle. One motion, the whole onesie opens. Compared to buttons and snaps, it feels like upgrading from dial-up to broadband.
The limitation: it only opens from the top. For a nappy change, you have to unzip the entire garment from the neck down, exposing your baby's whole torso to the air.
- Fast — one smooth motion
- No alignment needed in the dark
- One-handed operation possible
- No clicking sounds
- Must fully undress for nappy changes
- Exposes baby's chest to cold air
- Risk of skin pinching without a zip guard
- Zip can snag on fabric if rushed
Two-Way Zip
The 3am championOpens from the top and the bottom. The closure that understands parenthood.
Everything a one-way zip does, plus: it opens from the bottom, too. For a nappy change, you unzip from the ankle upward — accessing the nappy area while the chest stays zipped, warm, and undisturbed.
The two-way zip is, functionally, the best closure solution for baby onesies. It's fast, intuitive, works in the dark, works one-handed, doesn't make noise, and keeps baby warm during changes.
- Fastest closure — opens from top or bottom
- Nappy access without undressing baby
- Baby stays warm during changes
- Silent operation
- One-handed, works in the dark
- No alignment, no clicking, no fumbling
- More expensive than snaps or one-way
- Check for a zip guard — not all brands include one
- Less common on budget brands
Magnetic Closures
Clever but nicheInnovation meets a few unanswered questions.
Magnetic closures use magnets instead of snaps — the two halves click together automatically. Sounds brilliant in theory, and it is genuinely satisfying to use.
The concerns: magnets add weight and rigidity. They're also significantly more expensive — two to three times more than comparable options.
- Self-aligning — magnets find each other
- Very fast to close
- Quiet
- Satisfying tactile feedback
- Expensive (2–3× the price)
- Magnets add stiffness to the fabric
- Safety concerns (if a magnet detaches)
- Limited brand options
- Can interfere with medical devices
The Speed Test
We timed each closure type across 10 nappy changes (average time, including getting baby re-dressed).
Average nappy change time by closure
At 10 changes a day, the difference between buttons (95s) and a two-way zip (30s) adds up to almost 4 hours saved per month.
The Full Comparison
| Factor | Buttons | Snaps | One-Way Zip | Two-Way Zip | Magnetic |
|---|---|---|---|---|---|
| Speed | Slow | Medium | Fast | Fastest | Fast |
| 3am usability | Awful | Tricky | Good | Excellent | Good |
| One-hand use | No | With practice | Yes | Yes | Yes |
| Baby stays warm | No — full undress | Partial | No — opens from top | Yes — opens from bottom | Partial |
| Noise level | Silent | Click click click | Silent | Silent | Silent |
| Safety | Choking risk | Safe | Need zip guard | Need zip guard | Magnet concern |
| Skin comfort | No metal/plastic | Metal against skin | Zip against skin | With guard: excellent | Covered magnets |
| Price point | Budget | Budget | Mid | Mid–Premium | Premium |
The Verdict (Honest)
If you're buying onesies for a newborn and you plan to use them daily — especially for sleep — a two-way zip with a zip guard is the best closure available. It's faster, quieter, warmer for baby, and kinder to your sanity at 3am.
Press studs are perfectly fine for daytime bodysuits and layering pieces. Magnetic closures are a luxury option. Buttons are for photographs and special occasions. That is a hill we will die on.
FAQs New Parents Actually Ask
Can I mix closure types in my baby's wardrobe?
Absolutely. Most parents settle on zips for sleepwear and nighttime, and are more relaxed about snaps for daytime bodysuits. Optimise where it matters most — when you're least awake.
My baby's zip sometimes catches the fabric. What am I doing wrong?
Nothing — this happens. Pull the fabric gently away from the zip path with your free hand before zipping up. With a two-way zip, start from the bottom and zip upward; it snags less because gravity keeps the fabric taut.
Are zips safe for newborns?
Yes, provided the onesie has a zip guard. Zips are actually safer than buttons, which are a documented choking hazard if they detach. Look for a covered zip pull at the bottom too.
My mum says buttons are best because that's what she used. Is she right?
Your mum is a wonderful person who raised a wonderful child using the best options available at the time. But two-way zips didn't exist then. Progress is allowed.