E-commerce has increased in the fashion industry, multiplying both sales and returns and impacting sustainability. This research analyses how artificial intelligence applications could help reduce fashion online returns, by identifying AI tools currently developed and being used by fashion companies and exploring the willingness of consumers to use them. Two focus groups and a survey were delivered among online fashion consumers in Spain between March and September 2024. After analyzing the online habits of purchasing and returning of the participants, the results showed broad support for some of the AI tools proposed. They helped to make more accurate purchases and, therefore, possibly reduce the number of returns. Contrary to what one might think, participants with specific training in fashion were more reluctant to use these AI-based applications in their buying process. The incorrect size was identified as the main reason for returning clothes, and consequently, the most chosen apps were context chatbots as style assistants and virtual fit helping tools. The second reason for the return was dissatisfaction with the product; advanced searching tools for items from a determined inventory was also deemed useful by the participants for their purchases.