What is Alt Text?

When the element (usually an image) to which alt text is applied, is unresponsive and does not render, an alternative text (alt text) is rendered. Therefore, a screen reader software is able to read the alt text in place of the image. The alt attribute is in fact a substitute for the image displayed and helps image components to be machine-readable, which in return helps the search engine optimization process.

The World Wide Web Consortium (W3C) in charge of the standardization of the World Wide Web, recommends providing an alt text for every image displayed through HTML for accessibility, search engine optimization, and user-friendliness purposes. It also comes in handy when users may have images turned off to load faster a web page or to users with low vision or blindness who rely on special screen readers who are able to translate web page text into an audio or a tactile format (e.g. Braille).