Inserts included. Packaging may not or may not be included with this offer. This product is final sale and only available while supplies last. May not be returned. Not valid for store credit, refund, or exchanges. Color and/or closure may be substituted by Cotton Babies based on inventory availability.

bumGenius 4.0

{ one-size, pocket-style cloth diaper }

Best selling, top-rated, and recognized for its quality and performance. bumGenius 4.0 is a one-size, pocket-style diaper that will keep your baby dry and comfortable.

Look for our unique butterfly closure system to ensure that you are getting genuine Cotton Babies™ brand cloth diapers

Oeko‐Tex Standard 100 certification indicates that bumGenius diapers have been stringently tested and are free from harmful or problematic substances.

  • Stay‐dry lining is super soft and wicks moisture away from delicate skin
  • Waterproof outer cover and insert stopper prevents leaks
  • Accessible, replaceable, gentle elastic
  • Durable plastic snaps
  • 3x3 snap down design adjusts the sizing to fit small, medium and large sizes (approximately 8‐35+ pounds)
  • Trim, snug and comfortable stretchy tabs provide a custom fit
  • Pocket accommodates inserts for customized absorbency
  • Diapers are bundled with two inserts: a newborn insert and a one‐size insert for your older baby
  • Newborn insert works as an overnight booster for older babies or as extra absorbency for heavy wetters

Cloth diapering has never been so easy!

bumGenius One‐Size Cloth Diapers feature our patented butterfly closure system to provide a comfortable, trim fit. This simple design makes cloth diapering as easy as using disposables. The familiar design makes bumGenius one‐size cloth diapers perfect for care providers who might be resistant to cloth diapering (including daycares).

Buy Diapers Once

bumGenius One‐Size Cloth Diapers fit most babies from 8 to 35+ pounds. No sorting by size or having to carry multiple diapers when going out. Three snap‐downs on the front of the diaper allow you to easily adjust the size of the diaper as your baby grows. For newborns, fold down the insert stopper for an extra‐small rise.

Only the Best for Your Baby

The soft, waterproof outer fabric keeps the diaper trim on your newborn and toddler. Soft, sueded inner fabric gently wicks moisture away from your baby's skin. Super stretchy, gentle leg and back elastic with rolled out casings keeps in the yuk and help to keep red marks away. Our unique covered slot opening keeps your baby protected from moisture.


These wonderful pocket diapers make up about 95\% of my cloth diaper stash. They are my daily go to, my work horses they are easy to care for. I love how I can change the absorbency by adding inserts. I add a booster at night and sometimes at naptime.. I wash in tide and dry in the dryer so I'm "tough" on them and they have held up beautifully. They fit perfect on my Piggle when he was a about 1 month old and the same diapers still fit him at almost 2 and 1/2. The colors are cute the prints are cuter. Hands down it recommend these to any 1st time cloth parents.


Our very first stash of diapers did not compare to Bumgenius 4.0 pocket diapers. After trying our first bumgenius diaper which was Patch, my husband and I were amazed! We quickly sold off our "cheapies" to invest more fully into these! They quickly became our go to for leak free cloth diapering! Super easy to use! Our 4.0s and now 5.0s are the only diapers daddy will put on our little guy.


I love BumGenius 4.0 pocket diapers! I used fuzzibunz with my 1st and I absolutely despised them. Poor quality, leaked, and were not good quality. I was so frustrated that I finally gave up. Now, with my 2nd (5months old now) I decided to try BumGenius and I'm so glad I did. Great price! Great quality! Amazing product all around! I have had ZERO issues with these! Never had leaking issues or smells or anything. They are super easy to use and easy to wash. I would highly recommend BumGenius! And Cotton Babies is amazing too. Easy ordering and fast shipping. I ordered the snaps. BumGenius is golden. Will never go back to fuzzibunz or any other brand. :)


I would say that I'm overall satisfied with my 12-pack of diapers, they do the job and are the trimmest ones I've seen. However, if you're looking for a diaper to last through more than one child or a high quality diaper, this isn't it. My biggest problem is the "stay dry" micro-fleece liner and the flap to stuff the diapers in. The liner is a very flimsy fleece that doesn't wick moisture away very well. I've also had issues with the material just not getting clean compared to my other diapers (even after following instructions). The flap, on the other hand, needs to be pulled down well or else leaking around the waistband can occur too. In the future, I'd like to see BumGenius use better materials, especially considering that people pay a fair amount of their hard earned money to buy them!


I love these diapers! I ruined my first stash bc I washed them on a sanitize cycle regularly which makes the water hotter than normal and it definitely cut the life if my elastic and pul. But that's to be expected. I purchased some charlie bananas as well and notices that just by washing in hot water the pul is sticky and they get moist, not leak just feel moist when baby is wet. I actually purchased 6 4.0's from the seconds sale and so far I absolutely love them! I don't wash any ofy covers in hot water anymore though, just warm. I'm hoping that this will prolong the life of the elastic and the pul. Even if I have to buy a new set for my neXT baby after using this stash for 2 or more years I still save thousands of dollars! I recommend these to everybody I know that is thinking of cloth diapering or already cloth diapering. Love love love!!

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