What is alternative text (alt text) used for?

Alternative text, commonly referred to as "alt text," is specifically used to provide textual descriptions of images. This is crucial for web accessibility as it allows individuals who may have visual impairments or are using screen readers to understand the content and context of images on a webpage. The alt text serves as an auditory description that conveys what the image is about and its purpose, making visual information accessible to everyone, regardless of their ability to see.

This practice not only aids users with disabilities but also enhances the overall user experience by ensuring that all users can comprehend the content of the page fully. Good alt text should be concise yet descriptive enough to convey the image's essence effectively.

In contrast, the other choices do not relate to the purpose of alt text. Increasing website loading speed pertains to performance optimization rather than accessibility. Substituting for video content involves handling multimedia differently, while enhancing interactive features is associated with user engagement and usability rather than providing descriptive content for images. Thus, the primary function of alt text is indeed to provide those necessary textual descriptions of images.