Swim Diapers Size 1 Market Report: Sales Volume, Market Share, Leading Brands & Market Trends

Pampers is the best-performing swim diapers size 1 brand in July 2026, moving 99,000 units across 6 ASINs for 73.3% of Top 10 volume. HUGGIES follows with 28,000 units (20.7%), ahead of Hello Bello on 8,000 units (5.9%).

With 3 brands splitting the Top 10 and 100.0% of volume sitting with three of them, this is a concentrated shelf — the leaders hold multiple listings or one very high-velocity ASIN, so a new entrant competes against established review moats rather than an open field. Average selling prices among the leaders run from $13.99 to $19.60, which frames the price band a competing listing has to justify.

Based on July 2026 data, this shortlist surfaces the two kinds of ASIN worth keeping an eye on — the ones that just broke into the Top 10, and the ones growing fastest month over month. On the growth side, B0GQSRRGYN leads positive momentum with ▲ 300.0% MoM growth on 400 units, with B0FXYHC1MD close behind at ▲ 200.0% MoM on 3K units.

The two signals carry different weight. A fresh entrant means share has already changed hands — an incumbent gave up its place to make room, so any competitive set drawn up a month ago is now out of date. A steep growth rate works as the earlier warning: it marks demand that is still compounding, usually a month or two before the ranking catches up to it.