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Build Your Bikini, Any 2 Separates For $99

Free Shipping on US Orders Over $80

1 Free Exchange on Eligible Orders

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Front view of The Wavecrest Set showing a black knot front bikini top and high V cut bottoms on a model with white background
Woman wearing a blue bikini
Woman wearing a colorful bikini
Woman wearing a colorful bikini
Woman sitting on a rocky beach in a green bikini bathing suit | ahmeimae / M + M ahmeimae / M + M
Front view of Westerly tie-front bikini top in Abyss purple on model showcasing adjustable tie-front knot and mid-rise bottoms | alexhakim16 / S alexhakim16 / S
Front view of Westerly Tie-Front Bikini Top in tan on model showcasing adjustable tie-front and V-neck against white background | alexhakim16 / S alexhakim16 / S

PATENTED SWIM THAT FITS LIKE UNDIES®

The Wavecrest Set

$108.00 $108.00
[heading]: [value]
Westerly Tie-Front Bikini Top Westerly Tie-Front Bikini Top
$54.00
Size: XXS
Jennings V-Cut High-Waisted Bikini Bottom Jennings V-Cut High-Waisted Bikini Bottom
$54.00
Size: XXS
free shipping on US orders over $80
The peak of balancing edgeless cheekiness with coverage and lift.
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ships from CT, USA
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14-day returns
Free exchange icon
1 free exchange
Instructions - go to #instructions Details - go to #details Reviews - go to #reviews FAQs - go to #faqs
Front view of The Wavecrest Set showing a black knot front bikini top and high V cut bottoms on a model with white background
trying on your onewith

What to know when your onewith arrives!

What to know when your onewith arrives!

Front view of onewith black bikini-style underwear showcasing snug hip fit with pink arrows on cream background

1. your correct size SHOULD dig in a bit to start, then...

Torso and hands adjusting black bikini-style underwear at the hips to show fit

2. after warming up your onewith (aka giving it a stretch)

Front view of black bikini brief showcasing raw-cut, no-show undies design and smooth fit on light background

3. your onewith will be smooth like no-show undies!

1 FREE exchange on eligible US orders

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size inclusive (XXS-3XL)

Size-inclusive sizing icon

patented, US Patent No. 12,357,039

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traditional swimwear
vs. onewith swim

goodbye, tight seams and elastic. hello smooth, patented swim that fits like your favorite undies.

Front view of a model wearing a black bikini set showcasing a smooth, seam-free fit and high-waisted bottoms on a neutral background after
Front view of Westerly bikini top and high-rise black bottoms showing seam-free, no-dig fit against neutral background before
Angled reclining view of Westerly Tie-Front Better-Than-Seamless Bikini Top in black showcasing tie-front knot and raw-cut edges on sunlit sand
Light pink swatch
Edgeless... Better
Than Seamless!
Light pink swatch
dig-free + elastic free
Light pink swatch
Lay-flat, second-skin fit

why choose onewith?

2 layers of fabric, smoothly bonded, not sewn with seams that squeeze.

Three women in swimsuits posing against a vertical wooden-panel background
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Two women in black one-piece swimsuits standing at a lifeguard stand on the beach.

frequently asked questions

onewith can not guarantee that the inner grip strip inside of our suits does not contain trace amounts of latex. Therefore, if you have a latex or adhesive sensitivity/allergy, we recommend you exercising the same caution and sensibilities you would take in general when determining whether or not to use or wear a product that may contain latex or adhesive, should you have a known issue with these substances.

in general we are true-to-size. we have a handy-dandy size quiz on every product page. take it once and it will give you your best size for each & every style!
you can also reference our size guide here. there are fit notes on every product page to help you choose your best size!

we are a US-based company; our suits are designed in North America and made in China. all pieces are made of 80% nylon, 20% elastane.

our suits are 2 layers of fabric just like any other swimwear...it's just bonded, not sewn with tight seams, so that it lays flat on your skin like your favorite no-show underwear. with that, onewith is the same opacity as all other swimwear. if you are sensitive to ANY sheerness when wet, as with ALL swim, opt for a darker color.

sign up for restock notifications on the product pages of the item you want, and be sure to follow us on Instagram for the latest & greatest of all things onewith!

our suits are 2 layers of fabric just like any other swimwear; it's just bonded, not sewn with tight seams. so while it may appear to be thinner, it is actually the same thickness of material as most traditional swim. so if you're worried about a case of 🐫toe, while we can't guarantee our suits are frontal-wedgie-free, so-to-speak as every person's body is different...we can say that there is no reason why our suits would cause it more than any other swimwear. if you're ever worried about anything showing through, a general swim tip is to opt for a darker color or a suit in a pattern.

we design by demand and data. if we get enough requests for something & it stands to reason it might do well, we might just make it! for new color requests, please watch this video for more info on why we don't make a lot of colors.

⛔ we strongly discourage bracketing (ordering multiple sizes or styles with the intention of returning what doesn't work) as well as high-quantity first orders. while we completely understand the desire to find your perfect fit, this practice creates real inventory challenges for us as a small business, and also compromises hygiene best practices.

we're big believers in conscious consumerism and encourage small, mindful first orders. once you've found your perfect size and your new favorite swim, we absolutely love it when you stock up — just please do so with the intention of keeping your order, not returning the extras. we know this kind of large-order flexibility may feel standard with bigger retailers, but we ask that you consider how bracketing and high-volume returns affect a small business, its customers, and the environment.

returns of 4 or more items per order will be subject to a $15.95 processing fee in addition to the standard return fee.

in general we are true-to-size. please reference our size guide here. also, TAKE THE SIZE QUIZ! it is so helpful, we made sure of it :)

we offer a 14-day return/exchange policy on all swimwear, beginning the day of carrier-confirmed delivery. a customer's first exchange is free to ensure you find your perfect onewith fit. returns for store credit are also free; returns for a refund incur a $12.95 fee (additional fees apply for high-volume returns). all returns and exchanges must come back in original, unworn condition with the hygiene liner intact. Read more about the onewith return policy here.

in general our suits run true-to-size, but be sure to take the size quiz linked on each product page. the quiz is tailored to each style, so you'll always get the most accurate recommendation.

⚠️ NOTE: ITEMS MARKED FINAL SALE + INTERNATIONAL ORDERS ARE ABSOLUTELY, POSITIVELY FINAL SALE. no returns, no exchanges, no exceptions.

because we make swimwear that feels like underwear, our swim tends to be a great fit on so many bust sizes... from AA to J cup and beyond! check the product images to see our tops on a range of bust sizes. check out this blog post for a comprehensive guide on how to best pick your top size. pro-tip for choosing your onewith bikini top size: we don't size by cup! we'd recommend going with the same size top you would for a camisole.

we offer lots of content of our swim on different bodies all over our site + socials! Namely, we have a onewith wearer gallery all of our product pages, our ‘plus size’, ‘try-ons’, ‘customers’, and fuller bust’ highlights on Instagram, the coverage/support meter on product pages,, size guide page, and more! we have so much content with lots of different representation.

onewith is proud to offer international shipping!

all international sales are positively FINAL. no returns or exchanges are available for international orders.

shipping rate to your country is calculated at checkout, and is set by the carrier. in most cases, this rate also includes duties/customs! some exclusions may apply.

it's possible you only included a phone number for contact info when you placed your order. in this case, all order updates would be sent via text. if you're not able to find any order notifications via text, please check any other email addresses you have access to. if you're still not able to find the confirmation, please send an email to info@onewithswim.com and our team will be happy to assist you!

swim is an intimate garment, and therefore deeply personal. for that reason, we're happy to offer returns and exchanges on domestic, non-final sale orders — with a few conditions.

exchanges: onewith offers 1 free exchange on eligible US orders within 14 days of carrier-confirmed delivery.

returns: onewith offers returns on eligible US orders within 14 days of carrier-confirmed delivery. returns for store credit are free; returns for a refund are subject to a $12.95 fee. additional fees apply for high-volume returns (4+ items).. items purchased at a discount of 30% or more are eligible for store credit only. see our full return policy for details.

final sale: items marked final sale and all international orders are final sale — no returns, no exchanges, no exceptions.

Model wearing cove blue bikini with a smooth, no-dig fit, standing on a porch and holding a sign that reads ‘follow us @onewithswim’
@onewithswim
Front view of Westerly tie-front bikini top showing knot front and seamless bonded fabric on a model against a light wall
@itsmisslys
Close-up of black Foxon Multi-Way Bandeau bikini top showcasing adjustable straps on a model in shallow water
@ahmeimae
Three-quarter view of black Westerly bikini top and high-waisted bottoms showcasing a center front tie on a model at a pool
@traceydoes_
Three-quarter view of Foxon Multi-Way Bandeau bikini top in Cove brown showing seamless raw-cut fit on model with hibiscus background
@ivana_ferro