AltText

Alt text, short for alternative text, is a textual description of an image embedded in web content. It is read aloud by screen readers and displayed if the image cannot be loaded, helping users understand the image's purpose and content.

In HTML, the alt attribute of the image element provides this description. For decorative images that do not convey information, the alt attribute can be empty (alt=""). Screen readers will skip such images. Alt text should be concise but informative, focusing on the image's function or content.

Best practices include avoiding phrases like “image of” and ensuring the description conveys essential information within a few words or a short sentence. For complex graphics, the alt text may be brief while a longer description is provided elsewhere on the page, such as in a caption or a linked document.

Accessibility and standards: The WCAG guidelines emphasize that alt text should enable access to information and functionality. Longdesc is deprecated in HTML5; use long descriptions via separate content or ARIA attributes if necessary and ensure the page remains navigable with assistive technologies.

Examples: If the image shows a red tulip in a garden, alt text might be “Red tulip in a garden.” If the image acts as a button, alt text should describe the action, such as “Submit form.”