Swimwear quality is the category where the gap between a £15 bikini and a £120 bikini is most immediately visible and felt — not because luxury swimwear is inherently better-made in some abstract sense, but because the specific variables that determine swimwear longevity (chlorine resistance, UV stability, fabric recovery after repeated stretch and wet-dry cycles) are expensive to engineer and cheap to skip.
The £15 bikini that fades after two weeks of sun exposure, loses its shape after ten pool sessions, and stretches without recovering by the end of summer is not a saving — it’s the cost of the quality swimwear paid twice, plus the inconvenience of buying twice.
Chlorine resistance. Standard polyester/lycra swimwear degrades rapidly in chlorinated pool water. Chlorine-resistant fabrics — specified in the product description as chlorine-resistant or PBT (polybutylene terephthalate) fabric — maintain their integrity across hundreds of pool sessions that standard swimwear does not.
UV stability. UPF (ultraviolet protection factor) ratings and UV-stable dyes indicate whether the swimwear will maintain its colour through a season of sun exposure. Cheap dyes fade dramatically; UV-stable formulations maintain colour integrity.
Fabric recovery. The swimwear that maintains its shape after repeated wet-dry cycles is the swimwear that still fits correctly at the end of the season. Poor elastic recovery produces the stretched-out, unsupportive feel that makes swimwear unwearable after a few months.
Available at: Speedo (speedo.com), John Lewis, Decathlon
Best for: Those who swim regularly in pools and want chlorine-resistant swimwear that holds its shape across hundreds of sessions.
Speedo’s Endurance+ fabric is the competitive swimming standard — the PBT polyester construction maintains colour and shape across pool sessions that standard swimwear cannot withstand. The fabric is 100% chlorine-resistant, meaning pool chemicals do not degrade the elastic or fade the dye in the way they affect standard polyester-lycra blends.
For lap swimmers, open water swimmers, or anyone who swims more than twice per week, Speedo Endurance+ is the only swimwear category worth considering — standard fashion swimwear is unsuitable for regular pool use.
Available at: Eres (eresparis.com), Net-a-Porter, Selfridges
Best for: Those who want the finest quality holiday swimwear with the most enduring aesthetic and construction.
Eres is the Paris-based swimwear brand whose construction quality and aesthetic refinement represent the standard against which all luxury swimwear is measured. The fabrics are Italian — produced by the mills whose fabric quality defines European luxury goods — and the construction is exceptional. The silhouettes are clean, minimal, and designed to look correct regardless of current swimwear trends.
The Eres investment is real and produces proportionate return: the Eres bikini that was purchased five years ago looks the same as it did when new, fits the same, and will look the same in five more years. The cheap alternative replaced each summer produces less total quality at greater total cost.
Available at: Heidi Swim (heidiklein.com)
Best for: Those who want premium holiday swimwear with documented sustainable credentials and above-average construction.
Heidi Swim uses ECONYL — regenerated nylon produced from ocean plastic and fishing nets — in a construction that provides genuine durability alongside the sustainability credentials. The brand’s quality control is above the fast fashion swimwear market, and the designs are considered and wearable across seasons rather than trend-dependent.
Available at: Seafolly (seafolly.com), in stores, ASOS
Best for: Those who want quality holiday swimwear at mid-range prices with consistent sizing and reliable construction.
Seafolly is the Australian swimwear brand whose combination of quality fabric, reliable sizing, and accessible pricing makes it the most consistent recommendation in the mid-market holiday swimwear category. The fabrics hold their colour through a season of sun exposure better than most alternatives at the price, and the sizing is consistent enough for online purchasing.
Available at: ASOS (asos.com)
Best for: Those who want fashion-forward swimwear at accessible prices with adequate quality for holiday use.
ASOS’s premium swimwear collection uses better fabric than their standard swimwear range — the elastic quality and fabric density provide reasonable shape retention through a short holiday period. For those who want to follow swimwear trends without committing to the investment of Eres or Seafolly, ASOS Premium provides the most reliable accessible option.
Swimwear quality pays back in season-long shape retention and colour stability. Speedo Endurance+ for all regular pool swimmers — non-negotiable chlorine resistance. Eres for the investment holiday swimwear that will look the same in five years. Heidi Swim for premium sustainability credentials alongside quality construction. Seafolly for mid-range holiday quality with reliable sizing. Arena Pro for competitive swimming alternatives to Speedo. And ASOS Premium for the accessible fashion option with adequate quality for short holiday use. Know which context you’re buying for — pool swimwear and holiday swimwear have different requirements, and the same piece rarely serves both optimally.