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Free Shipping on US Orders Over $80

1 Free Exchange on Eligible Orders

5.0/ 5 over 50,000 happy customers

tired of your swimwear digging in? we fixed it.

Meet onewith swim. We took everything you hate about swimwear: the digging, the squeezing, the adjusting. We engineered it out. Patented, elastic-free, and built to fit like your favorite no-show undies.

10% Off Your First Order with code likeundies

Three pastel pink bubbles with sparkles and subtle iridescent highlights

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5.0/ 5 50k+ women who have gone edgeless

What people are saying

skeptic turned fan

"Was very skeptical on the fit, but these truly do feel like your no show underwear!"

Maritza R.

love them

“it actually feels secure. I forgot I was even wearing swim.”

Laura S.

they're perfect

"I’m obsessed, genuinely the best fitting bathing suit bottoms I’ve ever owned."

Kylie B.

as seen on

why we exist

onewith started on an apartment floor, buried under a pile of suits that all had one thing in common: they didn't fit right. So founder Hayley built one that did. Years of R&D and a patented construction later, the result is better-than-seamless, edgeless swimwear built around one obsession: making women feel at home in their bodies at the beach.

Three pastel pink bubbles with sparkles and subtle iridescent highlights

The onewith Difference

goodbye seams and elastic, hello smooth, patented fit that feels like your favorite undies.

Bonded, Elastic-Free Edges

Warm-Up Stretch Fit

Inner Grip Strip

Beyond-Seamless Look

Woman wearing a black scoop‑neck bikini top and high‑rise black bikini bottoms on a neutral gradient background with decorative sparkle stars

after

Woman in a black two-piece swimsuit (crop top, high-waist bottoms); torso and upper thighs visible.

before

the fit you've always wanted

That second-skin, nothing-there feeling of your favorite no-show undies. We just made it swimwear.

Dig-free and edgeless

Elastic-free, better-than-seamless

A fit that's truly onewith your body

The most flattering swimsuit you'll ever wear

Three pastel pink bubbles with sparkles and subtle iridescent highlights

Three pastel pink bubbles with sparkles and subtle iridescent highlights

See it in your size

Woman in a black onewith bikini sitting on rocks by the ocean — andrypena / XXS + XXS

Woman in a red onewith one piece swimsuit standing on a boat with blue water in the background — kareenasinghh / XS

Woman standing on a rocky shoreline wearing a bright blue bikini, hands behind her head — kareenasinghh / XS + XS

Woman in a red onewith one piece swimsuit standing on a boardwalk with greenery in the background — carolyn.mhickman / S

Woman wearing a blue onewith bikini standing against a wooden wall. — dayj.doll / S + S

Woman wearing a blue onewith bikini top in a pool — megdlyn / S

Woman in a blue onewith bikini and sunglasses standing on a balcony with a view of a marina — ivana_ferro / S + M

Woman in a black onewith bikini standing on a beach — alyssa.models / S + M

onewith founder Hayley wearing a onewith black one piece swimsuit taking a mirror selfie — onewithswim / S

Woman in black one-piece swimsuit standing on a muddy beach with hands on hips, wooden pilings and shallow water behind her. — ahmeimae / S

Back view of onewith Idlewild High-Neck One Piece in black showcasing low scoop back and high-cut leg with ocean background — ahmeimae / S

Woman wearing a black bikini on a beach — alexhakim16 / S + M

Woman in a black onewith bikini standing on a beach with water and sky in the background — ahmeimae / S + M

Woman wearing a brown onewith bikini with a bag — onewithswim / S + S

Woman in a onewith bikini and hat on a beach at sunset — carolyn.mhickman / S + S

Woman in a black onewith bikini and hat standing in the ocean — emily_shultis / S

Woman in a black onewith bikini posing by a pool — traceydoes_ / S + M

Woman wearing a blue onewith bikini taking a mirror selfie — onewithswim / S + S

Woman wearing a black onewith bikini taking a selfie — lordnavji / M + M

Woman in a blue onewith bikini standing on a dock by water — ahmeimae / M + M

Three-quarter view of Hampton bottom in black on a model showcasing high-rise, full-coverage fit with raw-cut edges at poolside — traceydoes_ / S + M

Smiling woman kneeling on wet sandy beach, wearing a black bikini, hands in her hair — anaidalyramos / M + M

Woman in a black onewith bikini standing against a teal door. — Anaidayl / M + M

Reclining woman wearing a black bikini top on wet rocks, showing necklaces and a ring — ahmeimae / M

Woman in a blue onewith bikini and pink hat by a pool — ivana_ferro / S + M

Woman in a black onewith bikini sitting on a beach with ocean in the background — alyssa.models / S + M

Woman in a black onewith bikini standing on a beach with water and sky in the background — ahmeimae / M

Woman in a black onewith bikini sitting on a counter — anaidalyramos / M + M

Woman in a black onewith bikini on a boat — ivana_ferro / S + M

Woman in a red onewith one piece swimsuit standing by the ocean — ashleyyharveyy / L

Woman sitting on a dock by a body of water wearing sunglasses and a black onewith bikini top. — ceciliakauffmanharris / L

Woman wearing a black onewith bikini standing on a beach — chloewoz / XL

Woman in a blue onewith bikini standing in a pool with a flower in her hair — summerleilani_ / XL

Woman wearing a black onewith bikini standing on a balcony. — chloewoz / XL + XL

Plus-size woman in a black bikini leaning on a white porch railing, smiling at the camera — chloewoz / XL + XL

Woman wearing a black onewith bikini standing on a balcony overlooking a beach with palm trees. — wendyfrita / 2XL + XL

Woman wearing a black onewith one piece swimsuit in a pool — gracedotymusic / 2XL

Woman in a blue onewith bikini holding a drink under a palm tree — cheyenneolson / 2XL

Mirror selfie of Idlewild High-Neck One Piece in Abyss black on model showcasing high neckline and full-coverage fit — gracedotymusic / 2XL

Woman in a black onewith bikini standing on a beach — gracedotymusic / 2XL + 2XL

Woman wearing a black onewith bikini sitting on a stool indoors. — gracedotymusic / 2XL + 2XL

Woman in a blue onewith bikini standing on a boat with rocky cliffs and blue water in the background — Marisa / 2XL + 2XL

Woman in a black onewith bikini standing on a rocky beach with houses and trees in the background. — tatumblinncoffey / 3XL + 3XL

hayleyhermsofficial / 3XL

Woman in a black onewith bikini standing on a sandy beach with water and boats in the background. — ariellamayamendes / 2XL + 3XL

We're confident you'll find your fit.

1 free exchange on eligible us-orders

14-day returns on eligible us orders

ships fast from ct, usa

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1 FREE exchange on eligible US orders

size inclusive (XXS-3XL)

patented, US Patent No. 12,537,039