Flap Happy Kids’ UPF 50+ Swim Hat Review

The Flap Happy is the only hat in this roundup that’s actually designed to get wet. Recycled polyester and spandex — the same basic construction as a rash guard — means it gets fully soaked and you barely notice, floats if it goes overboard, and crushes into a ball small enough to fit in a swim bag pocket after your toddler throws it on the ground. That last part is important. There is no chin strap on this hat. Oren (almost 2) removed it every time he noticed it was on his head. We’re including that as a feature, not a bug — the Flap Happy is designed for babies and young toddlers who are mostly stationary. For Oren, who has discovered both that hats exist and that they can be removed, it was past his age range.

3.4/5.0

Best kids’ sun hat for water babies and young toddlers

Flap Happy Kids’ UPF 50+ Swim Hat

Swims, dries fast and still looks like a hat afterwards. The one that goes in the bag when we do not know what the day holds.

Shop at REI$21

Sizes: S–XL (fits approx. ages 0–24 months) | UPF: 50+ | Material: 82–83% Recycled Polyester / 17–18% Spandex | Chin strap: None (elastic closure only)

Is the Flap Happy Swim Hat UPF 50+?

Yes, rated UPF 50+ on the recycled polyester/spandex fabric. Coverage includes the bill in front and the neck flap in back — face, ears, and neck are all covered when the hat is on. The elastic-only closure means “when the hat is on” depends entirely on whether your kid has noticed it yet. For babies who aren’t actively pulling at things on their head, this is a non-issue. For Oren at almost two, it was the primary issue.

Where we tested the Flap Happy Swim Hat

Gulf Shores, Alabama: Oren (almost 2) wore the Flap Happy across five days of beach and Gulf swimming. We ordered a size XL — one size up from what the age chart suggested — and it was still a snug fit on his almost-two-year-old head. The hat held on in Gulf breeze without assistance: the low-profile bill doesn’t catch wind the way a wider brim does, and the elastic kept it in place passively. The problem was active, not passive. When Oren noticed the hat, he removed it. When he was distracted, it stayed on.

The rogue wave that hit all eight hats simultaneously during a photo session confirmed the Flap Happy’s position at the top of the drying-speed rankings. It was wearable again faster than anything else we tested. Swimsuit fabric does not hold water.

Flap Happy Swim Hat features — what actually stood out

The fabric. 82–83% recycled polyester and 17–18% spandex is swimsuit construction, which has specific properties that no other hat in this roundup matches. It gets wet and dries almost immediately — after the Gulf wave incident, we shook it out and it was ready. It floats, which means if it goes in the ocean — thrown by a toddler, knocked off by a wave — it comes back to the surface. And it crushes completely: roll it into a ball, stuff it in a swim bag pocket, pull it out five minutes later intact. No structure to protect, no brim to crease.

The elastic-only closure is a deliberate design choice for the intended age range. No chin strap hardware means nothing to catch, nothing to choke on, nothing for a baby to grab and pull. The hat sits on the head and stays there through the elastic tension. For a six-month-old or a one-year-old who isn’t pulling at things on their head, this is clean and simple. For an almost-two-year-old with motor skills and opinions: see below.

The bill and neck flap coverage profile is good — face and ears covered by the bill, back of the neck covered by the flap. The bill is lower-profile than a wide-brim hat, which is part of why it holds in a breeze without a chin strap: less surface area for wind to catch.

What doesn’t work on the Flap Happy Swim Hat

No chin strap. This is the defining limitation of the hat for any kid who is old enough to remove it. Oren at almost two removed it every time he noticed it was on his head, which was frequently. There is no retention backup. The elastic works when the fit is right and the kid is stationary; once they find the brim, it comes off in one pull.

Sizing runs small. We ordered XL for an almost-two-year-old and it was a snug fit. The XL is the largest size available. If you’re buying for a toddler on the larger end of the age range, this might simply not fit — check the measurements against your kid’s head circumference before ordering.

This is also not a trail or dry-land hat. The swimsuit fabric is optimized for water use. On a dry, hot day on trail, we’d reach for anything else in this roundup — the Flap Happy is purpose-built for pool and beach.

How to care for the Flap Happy Swim Hat

Machine wash. The Amazon listing confirms machine wash — swimsuit fabric handles washing exactly the same as a rash guard or swimsuit. Cold water, gentle cycle, line dry or lay flat. The recycled polyester/spandex construction doesn’t need special treatment. We’ve washed ours alongside swimsuits without issue.

Does the Flap Happy Swim Hat pack down?

Completely. It’s swimsuit material — roll it into a ball and it fits in a swim bag pocket, a diaper bag side pocket, or a jacket pocket. Pull it out later: intact, no crease, no damage. This is the most packable hat in the roundup by a significant margin. After Oren removed it for the fourth time at Gulf Shores, we stuffed it in a pocket and didn’t think about it again until we needed it.

Flap Happy Swim Hat sizing guide

Size up. Order one size larger than the age chart suggests. We ordered XL for an almost-two-year-old and it was a snug fit — which means the S, M, and L sizes are genuinely running small. If your baby is at the upper end of any size range, go up. The elastic closure gives you some room to absorb a slightly large hat; a too-small hat just doesn’t fit and creates a retention problem the elastic can’t solve. Check the brand’s specific head circumference measurements before ordering rather than relying on the age ranges alone.

Who is the Flap Happy Swim Hat best for?

Babies. Specifically: babies under 18 months who will be at the pool or beach all summer and need a hat that keeps up with water use without any hardware complications. For families spending significant time in the water with a young baby, this is the right hat — it’s faster drying, more packable, and simpler to use than any other hat here. Once your child hits the hat-removal phase, move to the JAN & JUL Quick-Dry for a hat with a breakaway chin closure that at least slows the process down.

Pro tip: Size up from what the chart says — the sizing runs small and the XL is the largest available. Check the head circumference measurement on the product listing and compare it to your kid’s actual measurement before ordering.

How the Flap Happy Swim Hat compares to other kids’ sun hats