The most flattering swimsuit you'll ever wear.

No elastic, no edges, no seams digging in to cut at your shape. onewith is bonded instead of sewn, so it lays flat against your skin and gives you one smooth, uninterrupted line. The result is a second-skin fit that flatters everywhere your old swim used to pinch and pull.

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10% Off Your First Order with code likeundies

over 50,000 happy customers

Three pastel pink bubbles with sparkles and subtle iridescent highlights

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.

the onewith community

Woman in straw hat and mauve swimsuit sitting at the pool edge reading a book, towel and snacks beside her. — **Size: S + M**

Woman in a black bikini sitting on a sandy beach, leaning on one arm and looking down. — **Size: S + M**

Front view of blue onewith two-piece swimsuit on plus-size model with knot-front top and raw-cut bottoms at indoor pool — **Size: L**

Woman in red swimsuit looking over a railing with turquoise water and a volcanic island in background — Size: L

Woman in red one-piece swimsuit standing on pool deck next to tropical plants, smiling toward the camera. — Size: S

Woman in black swimsuit smiling at camera beside a backyard pool — Size: 2XL

Person in a red swimsuit climbing a boarding ladder onto a boat over blue water. — Size: XS

Woman in a bright blue bikini looking over her shoulder, standing against a vertical wood-paneled wall — Size: S / S

Woman in black bikini standing on rocky beach, smiling; ocean and palm trees in background. — Size: L

Woman wearing blue bikini top and sunglasses, smiling with arm tattoos, outdoors by trees and sky. — Size: S

Woman in blue bikini and sunglasses holding a red drink cup under a palm tree. — Size: 2XL

Woman in black bikini standing on sandy beach path near wooden posts under a cloudy sky — Size: XL / XL

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.

The onewith Difference

Most swimwear cuts into you with seams and elastic that break up your line and leave marks. onewith doesn't. Our edges are bonded instead of sewn, so the suit lays flat against your skin for one smooth, uninterrupted line that flatters from every angle.

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

A smooth, second-skin fit that follows your shape instead of fighting it. No digging, no bulging at the edges, just a clean line that makes you look and feel your best.