Large. The sole is quite stiff, not flexible at all. I don't understand how shoe designers forget that our human feet naturally flex when we walk. Nice pattern and colors. The photo shows a size 4 toddler size comparison next to a size 5/6 Speedo water boot (which is a bit too big for my daughter)! I will keep them as they are cute and will probably fit my daughter in a few months or so but disappointed because I bought them to fit her now at her current size 4 and they don't seem any size…