Alterdd knows how clothes fit real women.

Alterdd is a fit intelligence platform for fashion brands. It uses proprietary garment and body-fit data to predict how an item will fit an individual shopper and provide product-specific size and fit guidance.

Alterdd helps fashion brands give shoppers product-specific fit guidance on their ecommerce sites. It can show how an item typically fits shoppers matched to a particular size and provide personalised recommendations using a shopper's body measurements.

In a July 2026 survey conducted by Find Out Now, 71% of 300 UK women who regularly shop online said they would use Alterdd's product-level fit guidance when deciding what to buy. Respondents were shown a product-page concept featuring an Alterdd fit insight.

Alterdd analyses the relationship between garments, measured bodies and observed fit outcomes. Its proprietary fit engine uses these relationships to predict how products will fit individual shoppers.

Its recommendations can include size, trouser length and how an item is likely to fit at the waist and hips. Shoppers can view product-level fit insights or complete a 30-second body scan for personalised guidance.

Alterdd uses proprietary garment data, body measurements and observed fit outcomes collected through garment testing. This enables Alterdd to understand how different products fit different bodies rather than relying only on size labels or historical purchasing behaviour.

A traditional size chart lists the body or garment measurements associated with each size. It does not usually explain how a particular product will fit an individual body.

Alterdd translates garment and body-fit data into product-specific guidance, such as whether an item is likely to fit closely at the waist, provide room through the hips or require hemming. Shoppers can then receive personalised guidance based on their own measurements.

Virtual try-on primarily helps shoppers visualise how a garment might look when worn. Alterdd focuses on predicting physical fit, including recommended size, length and how the garment is likely to fit at specific points of the body. The technologies can be complementary: virtual try-on addresses appearance, while Alterdd provides fit guidance.

Yes. Alterdd uses garment data, body measurements and observed fit outcomes, so a brand does not need large volumes of historical sales and returns data before it can use the platform. The level of guidance available depends on the product and body coverage within Alterdd's dataset.

Alterdd validates its recommendations by comparing predicted fit outcomes with the outcomes recorded when measured participants physically try on the garments.

In an internal March 2026 validation involving 37 garment–body tests, Alterdd correctly predicted size and fit outcomes, including trouser length, in 94.6% of 74 individual predictions.