I do believe these run small. That is why I love them!! They are the only underwear I could find to fit my skinny 2 year old when he was potty training, and now they are my boys favorite underwear. They seem comfortable (no complaints from my boys) and don't stretch out a ton like some other brands we have tried. The boxer briefs are my favorite style for little boys and these are perfect. Like I said, these do run small, so size up one if your kid is average size.

Pros:
Tagless
Dont stretch out
Fun prints but can also find them in solids
Great fit

Cons:
Run small (which was actually a pro for me)

The size 4T fits my stocky 3 year old and thin 5 year old perfectly!