7 October 2026International edition
Vol. I · No.
7 October 2026
AI in Fashion
DAILY
The daily briefing on AI in the fashion business
Where fashion meets artificial intelligence.
Glossary

What is A/B testing in fashion e-commerce?

A method of comparing two versions of a page, message or feature by showing each to a random group of users and measuring which performs better.

In short

A/B testing is a method of comparing two versions of something, such as a product page, email or feature, by randomly showing each version to a different group of users. The version that performs better on an agreed metric, such as conversion rate, is kept.

How does it work in practice?

A team defines a hypothesis, for example that showing on-model images first on the PDP will increase add-to-basket rates. Visitors are randomly split into two groups: group A sees the current page and group B sees the new version. After enough visits, the results are compared with a statistical test to check whether the difference is likely to be real. Tests with more than two variants or several changing elements are called multivariate tests.

Why does it matter for fashion businesses?

Small changes to imagery, size guidance, delivery messages or filters can change how customers shop, and opinions inside a company often differ. A/B testing provides evidence before a change is rolled out to everyone. In B2B, brands can test portal features with retail buyers, such as reorder shortcuts or order minimum reminders, although lower traffic means tests often need to run longer.

How is AI changing it?

AI tools can generate many variants of copy or imagery to test and analyse results faster. Methods such as multi-armed bandits shift traffic automatically towards better-performing versions while the test is running. Personalisation engines go further and show different versions to different customer segments, which requires careful testing design so effects are not mixed up.

Common pitfalls

  • Stopping a test as soon as one version looks ahead, before results are reliable.
  • Measuring clicks while ignoring returns, margin or long-term customer value.
  • Running overlapping tests on the same page that affect each other.
  • Testing during sales or campaigns that are not typical of normal trading.

Frequently asked questions

How long should an A/B test run?

Long enough to reach the planned sample size and to cover at least one full weekly cycle. The required duration depends on traffic, the baseline conversion rate and the size of the effect being measured.

What can fashion brands A/B test?

Common tests include product images, size and fit guidance, page layouts, search and filter options, recommendation logic, delivery and returns messages, email subject lines and checkout steps.

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