Sun Protection for Kids: Long Sleeve Swimsuits vs. Rashguards

Quick answer

For most kids, a long sleeve rashguard offers the best balance of sun protection, flexibility, and quick-drying comfort for active beach and pool play. Choose a long sleeve swimsuit when you want a one-piece design that stays put and minimizes exposed skin, especially for younger children or those who prefer a snug, full-coverage fit.

When the sun is blazing and your kids are ready to splash, protecting their skin from UV rays is a top priority. Two popular options dominate the market: long sleeve swimsuits and rashguards. Both provide more coverage than a traditional tankini or swim trunks, but they differ in design, fit, and function. Understanding these differences helps you pick the right gear for your child's swimming style and skin sensitivity.

In this comparison, we break down the key tradeoffs between long sleeve swimsuits and rashguards, using real examples from the NUNUNU collection. We'll look at what each type offers, who it suits best, and how to ensure a proper fit. By the end, you'll know exactly what to pack for your next family beach day.

What is a long sleeve swimsuit?

A long sleeve swimsuit is a one-piece garment that covers the torso and arms, typically made from swim-specific fabrics like nylon or spandex. These suits often feature a snug, athletic fit to reduce drag in the water and keep everything in place during active play. Many designs include a zipper or snaps for easy on and off, and some have built-in sun protection (UPF) ratings.

Long sleeve swimsuits are ideal for younger kids who might not keep a separate shirt on, or for parents who want a single, no-fuss piece. They also minimize the chance of a shirt riding up and exposing skin. However, they can be warmer in hot weather and may feel restrictive for older kids who prefer more freedom of movement.

What is a rashguard?

A rashguard is a snug-fitting, long or short-sleeved shirt designed for water activities. Originally worn by surfers to prevent rashes from board contact, they are now a staple for any water play. Rashguards are typically made from quick-drying, stretchy fabrics like polyester or spandex, and many offer UPF 50+ sun protection. They are worn with separate swim bottoms, allowing for mixing and matching sizes and styles.

Rashguards are incredibly versatile: they can be worn in the water, on the beach, or even as a light cover-up. They allow for easy bathroom breaks since the top and bottom are separate. On the downside, they might ride up during vigorous play, and you need to ensure the bottom stays put. For kids with sensitive skin, the flat seams and soft fabrics of many rashguards are a plus.

Key differences: coverage, fit, and convenience

Coverage: Both long sleeve swimsuits and rashguards cover the arms and torso, but a long sleeve swimsuit often provides a more continuous layer because it's one piece. Rashguards can leave a gap at the waist if they ride up, though a well-fitted one minimizes this.

Fit: Long sleeve swimsuits typically have a more athletic, compressive fit, which some kids find restrictive. Rashguards come in a range of fits, from relaxed to athletic, and are often easier to move in. Consider your child's comfort: if they hate tight clothing, a looser rashguard might be better.

Convenience: Rashguards win on convenience for bathroom breaks and mixing sizes. Long sleeve swimsuits are simpler to put on wiggly toddlers and ensure the shirt stays down. For sun protection, both work well, but check the UPF rating: a UPF 50+ fabric blocks 98% of UV rays.

What to look for in sun-protective swimwear

When shopping for kids' sun protection clothing, look for a UPF rating of 50+ for the best defense. Check the fabric: quick-drying, stretchy materials like nylon or spandex are comfortable and hold their shape. Consider the coverage: long sleeves are a must for extended sun exposure, and a high neck or collar adds extra protection for the back of the neck.

Also, think about ease of wear. For babies and toddlers, features like snaps at the crotch or shoulder flaps make dressing easier and diaper changes less of a hassle. For older kids, a rashguard with a full zip might be easier to take off after a long day. And remember, no swimwear replaces sunscreen on exposed areas like the face, hands, and feet.

Tradeoffs at a glance

• Sun protection: Both long sleeve swimsuits and rashguards can offer UPF 50+ protection. Long sleeve swimsuits provide continuous coverage, while rashguards may leave a gap if they ride up. Check the UPF rating and opt for a snug fit to ensure full coverage.
• Comfort and movement: Rashguards are often more flexible and breathable, making them a better choice for active kids. Long sleeve swimsuits can feel warmer and more restrictive. If your child is sensitive to tight clothing, a rashguard might be more comfortable.
• Ease of use: Rashguards with separate bottoms are easier for bathroom breaks. Long sleeve swimsuits are simpler for babies and toddlers, especially with snaps or zippers. Consider your child's age and independence when choosing.

NUNUNU options to consider

• nu sporty bikini: two piece swimsuit | elastic waistband finally a bikini that is made for kids who are just looking to play. & win, of course. we made this one with a little extra fabric held down by our branded elastic band at the waist & chest so it stays put no matter how hard they’re playing. plus the top has a racerback strap design so the only thing that will be moving around is your kid. it’s black but has nu in white... If you're considering a two-piece for easier bathroom breaks, this sporty bikini offers extra security with elastic bands and a racerback, but it's not a long sleeve option—so pair it with a rashguard for full arm coverage.
• road web onesie: your baby is the one giving directions in this road web print onesie for baby boys & girls. it’s made of ultra cozy fine rib fabric and warm & toasty long sleeves. this onesie has a classic shape that goes on with zero friction. snaps at the crotch make diaper changes a no-fuss situation, and shoulder flaps let you pull it down from the top—whatever’s easiest in the moment. While not a swimsuit, this long sleeve onesie shows NUNUNU's attention to easy dressing and comfort—features to look for in sun-protective swimwear for babies, like shoulder flaps and snaps.

Which should you choose?

Best for

• Long sleeve swimsuits: Babies, toddlers, and kids who prefer a one-piece, no-fuss option that stays in place.
• Rashguards: Active older kids, water sports enthusiasts, and those who want the flexibility to mix and match sizes.

Not for

• Long sleeve swimsuits: Kids who dislike tight clothing or need frequent bathroom breaks.
• Rashguards: Toddlers who might pull at the shirt, or parents who want a single-piece garment.

Ultimately, the best choice depends on your child's age, activity level, and comfort preferences. For maximum sun protection with minimal fuss, a long sleeve swimsuit is a solid pick. For versatility and breathability, a rashguard is a winner. Whichever you choose, remember to apply sunscreen to exposed areas and reapply often. With the right gear, your kids can enjoy the sun safely all summer long.