Size 1 Diapers

Size 1 diapers are such a special milestone – they're often baby's first step up from those tiny newborn days! At Alppi Baby, we've crafted our size 1 collection with the same alpine-inspired comfort and LiquidLock™ technology that gives you confidence during those beautiful, messy early months when every day brings new adventures.

Size 1 Diapers with Superior Protection

You know those middle-of-the-night changes and busy mornings when you need a diaper that just works? We've got you covered with absorption that actually delivers.

• LiquidLock™ core holds 233% more liquid than leading brands
• 2x faster absorption means less time against baby's sensitive skin
• 3x absorbency capacity for those longer stretches between changes
• Reliable blowout protection that saves your sanity (and laundry!)

Need something extra special? Check out our Staff Pick collection for staff-approved favorites.

Breathable Softness Your Baby Will Love

There's nothing like seeing your little one comfortable and happy. Our Cloudfresh™ fabric keeps things gentle while your baby discovers the world around them.

• 20% more breathable so baby stays cool during active play
• 60% thinner design that doesn't add bulk under those adorable outfits
• Cloud-soft materials that feel like a gentle hug
• Flexible fit that moves with all those precious wiggles and rolls

Baby-Safe Diapers for Peace of Mind

Moms read every label carefully. That's why we've made sure every ingredient meets our highest safety standards.

• Totally chlorine-free core because your baby deserves the purest materials
• No fragrance, latex, dyes, parabens, or phthalates – just clean protection
• Dermatologist-tested for even the most sensitive skin
• Made in FDA-registered facilities with rigorous safety testing

Find additional safe, gentle choices in our Safety Page Collection.

Thoughtful Design for Real Life

We know diaper changes happen everywhere – nurseries, car backseats, park benches. Every detail is designed to make your life just a little bit easier.

• Stretchy waistband and soft tabs that won't pinch or pull
• Individually wrapped diapers that stay fresh and clean
• Sweet Alppi characters that make diaper time a little more fun
• Convenient subscription delivery so you never run out

Looking for our absolute softest option? You'll love our Wispy Cloud Diaper collection.

Frequently Asked Questions: Size 1 Diapers

What age do babies stay in size 1 diapers?

Most little ones wear size 1 from around 2-8 weeks old through about 2-4 months, depending on their birth weight and growth rate. Babies typically move into size 1 once they outgrow newborn diapers around 8 pounds.

What weight is a size 1 diaper?

Size 1 diapers fit babies weighing 8-14 pounds perfectly. This sweet spot usually covers those early months when babies are establishing feeding routines and growing steadily. Weight is always more reliable than age for getting the right fit.

How to know when to go up in diaper size?

Watch for telltale signs like frequent leaks, red marks around the waist or thighs, or tabs that barely reach the front. The diaper should feel snug but comfortable, like a gentle hug. When in doubt, sizing up often solves mysterious leak issues.

Can my 7lb baby wear size 1 diapers?

Your precious 7lb baby will be most comfortable in newborn size diapers. Size 1 will likely be too big and may cause leaks or gaps around those tiny legs. Stick with newborn until baby reaches closer to 8 pounds for the best fit.

Size 2 Diapers

Size 2 diapers mark an exciting phase when your little one is becoming more active and curious about everything around them! Alppi Baby's size 2 collection features our signature LiquidLock™ core and ultra-soft Cloudfresh™ materials, giving you the confidence to let your growing explorer discover their world while staying comfortably dry and protected.

Size 2 Diapers with Maximum Absorption

Active babies need diapers that can keep up with longer playtime and more adventurous days. Our advanced technology ensures reliable protection when you need it most.

• LiquidLock™ core holds 233% more liquid than leading competitors
• 2x faster absorption keeps moisture away from busy little bodies
• 3x absorbency capacity for extended wear during naps and overnight
• Superior blowout protection for crawling, rolling, and exploring

Looking for tried-and-true favorites? Browse our Staff Pick collection for parent-tested winners.

All-Day Comfort for Active Babies

When your little one is on the move, comfort becomes everything. Our Cloudfresh™ fabric technology keeps them feeling fresh and happy through every adventure.

• 20% more breathable design prevents overheating during active play
• 60% thinner profile won't slow down crawling or cruising
• Incredibly soft materials that feel gentle against sensitive skin  
• Flexible construction that moves naturally with growing bodies

Gentle Safety for Growing Skin

Your baby's skin is still so delicate, even as they grow stronger and more active. We've created every size 2 diaper with the purest, safest ingredients.

• Totally chlorine-free core made with premium materials
• Free from fragrance, latex, dyes, parabens, and phthalates
• Dermatologist-tested formula perfect for sensitive skin
• Manufactured in FDA-registered facilities with strict quality controls

Looking for our most gentle options? Check out our  Safety Page Collection. of specially curated safe diapers.

Smart Features for Busy Parents

Chasing after an active baby means you need diapers that make changes quick and easy, whether you're at home or on the go.

• Stretchy waistband and gentle tabs for secure, comfortable fit
• Individually sealed diapers maintain freshness and hygiene
• Adorable Alppi characters that make diaper changes more enjoyable
• Flexible subscription service delivers exactly when you need them

Experience our cloud-like softness with the Wispy Cloud Diaper collection.

Frequently Asked Questions: Size 2 Diapers

At what age do babies need size 2 diapers?

Most babies transition to size 2 diapers around 2-6 months old, though timing varies with individual growth patterns. Active babies who are rolling and moving more may need the extra room and protection that size 2 provides. Weight is always a better indicator than age for proper sizing.

What weight are size 2 diapers for?

Size 2 diapers are designed for babies weighing 12-18 pounds. This weight range typically covers active infants who are becoming more mobile and curious. The roomier fit accommodates growing bellies and increased movement throughout the day.

When to change diaper size from 1 to 2?

Make the switch when your baby reaches 12 pounds or shows signs that size 1 is getting snug. Look for red marks around the waist, frequent leaks, or difficulty fastening the tabs comfortably. Many parents size up when they notice their baby seems uncomfortable or fussy during changes.

How to know if a diaper is too small?

Watch for red marks or indentations around your baby's waist and thighs after removing the diaper. Frequent leaks, tabs that barely reach the front panel, or difficulty getting two fingers under the waistband also signal it's time to size up for better comfort and protection.

Size 4 Diapers

Size 4 diapers are made for growing babies who need a comfortable fit, reliable absorbency, and gentle materials they can wear all day. Alppi Baby pairs advanced protection with alpine‑inspired comfort, so your little one can explore without worry.  

Size 4 Diapers That Fit Active Babies Perfectly  

By the time your baby reaches size 4, they’re more active than ever—crawling, climbing, and maybe even taking those first steps. That means their diapers need to fit securely, move with them, and keep leaks away without leaving red marks.  

What makes the fit work:

• Stretchy waistband that flexes with every wiggle  
• Soft hook tabs that adjust easily  
• Gentle leg cuffs that seal leaks without irritation  
• Sized for babies 22–37 lbs  
  

Looking for something extra light and soft? Try our Wispy Cloud Diapers.  

Long‑Lasting Dryness With LiquidLock™  

Older babies need more absorbency, and that’s where Alppi Baby’s LiquidLock™ core makes all the difference. It absorbs 2x faster and locks away 233% more liquid than leading brands, keeping skin dry during naps, playdates, and overnight.  

Absorption you can count on:

• LiquidLock™ core for maximum dryness  
• 2x faster absorption to protect skin  
• Overnight leak protection that lasts  
• Wetness indicator for easy checks  
  

Not sure which diapers parents love most? Check out our Staff Picks Collection.  

Gentle Cloudfresh™ Comfort for Sensitive Skin  

Sensitive skin needs breathable, hypoallergenic protection. That’s why Alppi Baby uses Cloudfresh™ fabric—20% more breathable and 60% thinner than typical diapers—so your baby stays cool, comfy, and rash‑free.  

Made safe for sensitive skin:

• Cloudfresh™ fabric for superior airflow  
• Hypoallergenic and dermatologist‑tested  
• Totally chlorine‑free (TCF) pulp  
• Free from dyes, fragrances, latex, parabens, and phthalates  

Want diapers made with safety as the top priority? Explore our Safety Collection for more gentle, hypoallergenic options.  

Thoughtful for Parents, Gentle on the Planet  

Alppi Baby believes what touches your baby’s skin should also be kind to the world they’ll grow up in. From FSC‑certified pulp to eco‑friendly packaging, every detail is designed with care.  

Eco‑friendly details you’ll love:

• Responsibly sourced, FSC‑certified wood pulp  
• Individually sealed diapers for hygiene and convenience  
• Produced in FDA‑registered, CPC‑certified facilities  
• Packaging made to reduce waste  

FAQs About Size 4 Diapers  

What age is a size 4 diaper for?  

Most babies wear size 4 around 18 months and up. Every child is different, so age is just a guide. Weight and fit are better ways to check.  

When to move from size 4 to 5 diapers?

If diapers feel snug or leaks happen more often, it’s time to size up. Red marks on the waist or thighs are another clue. Comfort is always the best guide.  

How many pounds is a size 4 diaper?

Size 4 diapers usually fit 22–37 lbs. Always check the package since ranges vary a little. Fit matters more than the number.  

Do size 4 diapers hold more pee?

Yes, they’re made to hold more liquid than smaller sizes. That’s important for older babies who pee more and may wear diapers longer. Even so, frequent changes are still best for skin health.  

Size 5 Diapers

Size 5 diapers are designed for growing toddlers who need extra protection, a flexible fit, and gentle comfort for busy, active days. Alppi Baby combines LiquidLock™ absorbency and Cloudfresh™ breathability to keep little ones dry, safe, and comfortable.  

Size 5 Diapers That Keep Up With Toddlers  

By the time your baby reaches size 5, they’re running, climbing, and exploring nonstop. These diapers are made to stay secure while giving them the freedom to move without leaks or red marks.  

What makes the fit so reliable:

• Stretchy waistband that adapts to every twist and turn  
• Soft hook tabs that adjust easily for comfort  
• Gentle leg cuffs that seal in leaks without irritation  
• Designed for toddlers 27+ lbs (12–17 kg)  
  

Looking for something extra light and soft? Try our Wispy Cloud Diapers.  

All‑Day and Overnight Dryness With LiquidLock™  

Toddlers need a diaper that can handle more liquid and longer wear times. That’s why Alppi Baby’s LiquidLock™ core absorbs 2x faster and locks in 233% more liquid than leading brands, keeping your child dry during naps, play, and overnight.  

Absorption you can trust: 

• LiquidLock™ core for maximum dryness  
• 2x faster absorption to protect skin  
• Overnight reliability with advanced leak protection  
• Wetness indicator for quick checks  
  

Not sure which diapers parents love most? Check out our Staff Picks Collection.  

Gentle Cloudfresh™ Comfort for Sensitive Skin  

Even as babies grow, their skin stays delicate. Cloudfresh™ fabric is 20% more breathable and 60% thinner than standard diapers, keeping toddlers cool, comfortable, and rash‑free.  

Why they’re safe for sensitive skin:

• Cloudfresh™ fabric allows superior airflow  
• Hypoallergenic and dermatologist‑tested  
• Totally chlorine‑free (TCF) pulp  
• Free from fragrances, dyes, latex, parabens, and phthalates  

Want diapers made with safety as the top priority? Explore our Safety Collection for more gentle, hypoallergenic options.  

Thoughtful for Parents, Gentle on the Planet  

Alppi Baby makes diapers that care for your child and the world they’ll grow up in. From responsibly sourced pulp to eco‑friendly packaging, every detail supports sustainability and peace of mind.  

Eco‑friendly details you’ll love:

• FSC‑certified wood pulp from responsible forests  
• Individually sealed diapers for hygiene and convenience  
• Produced in FDA‑registered, CPC‑certified facilities  
• Packaging designed to reduce waste  

FAQs About Size 5 Diapers  

What age is size 5 diapers for?

Many toddlers wear size 5 around 18 months and up. Age is only a guide since every child grows differently. Weight and fit are better indicators.  

What's the difference between size 4 and 5 diapers?

Size 5 diapers are larger and designed for toddlers over 27 lbs (12–17 kg). They offer more absorbency and a roomier fit. Size 4 works best for babies 22–37 lbs.  

How many kg is a size 5 diaper?

Size 5 diapers typically fit babies 12–17 kg (27+ lbs). Always check the package for brand‑specific ranges. Fit should matter more than the number.  

When to move up in diaper size?  

It’s time to size up if diapers feel snug, leaks happen often, or red marks appear. Comfort and dryness are the best guides. Every child grows at their own pace.