Due to the use of new technologies and ongoing digitization, there is a significant increase in the popularity of online stores. More and more, consumers appreciate the ease of online shopping, enjoying the ability to explore a diverse array of products from the comfort of their own homes. The wide range of products available in online stores allows consumers to precisely tailor their purchases to their individual preferences and needs. However, too much information on a page can lead to cognitive load, affecting visual attention and purchasing decisions. The article focuses on an innovative approach to measuring the impact of cognitive load on the purchasing decision-making process in online stores. The authors focus on psychological aspects, including reducing the influence of external factors, to obtain more reliable results. Understanding how cognitive load affects online shopping decisions is crucial for designing effective, user-friendly e-commerce platforms.