The ALT attribute (or simply ‘alt’) is the HTML designation utilized within HTML and XHTML to specify alt text (alternative description). This descriptive text is employed whenever the intended viewer is unable to perceive or interact with the element it is designed to represent. In the realm of SEO, alt text is most commonly applied to visual media such as images.
When a site visitor is unable to engage with a specific web component, such as a photograph, alt attributes (alt text, in particular) provide essential utility. For instance, a visitor with a visual impairment might not be able to see a video or picture, but an adaptive device can narrate its alt text to them. This same individual could not discern a bright yellow ‘warning’ icon displayed as an image, whereas useful alt text might simply read: “Warning!”
Fundamentally, an alt attribute is designed to act as a stand-in for a web element (meaning, it serves as its alternative). It usually contains descriptive content, but this is not a mandatory requirement.
Alt attributes also play a pivotal role in SEO. This is because the automated bots used by search engines cannot visually process images on web pages, but they can interpret alt text. By incorporating alt text for your visual content, you simultaneously make your information more accessible and boost your site’s search engine standings.