alttekst

Alttekst is the textual alternative for images in web pages, commonly implemented via the alt attribute in HTML. In Dutch usage, the term alttekst describes the content or function of an image for users who cannot view it. It also serves to communicate information when an image cannot be loaded and to help search engines understand the image.

Purpose and usage: The primary purpose is accessibility. Screen readers read the alttekst to convey the image’s meaning to blind or visually impaired users. If the image is purely decorative and conveys no information, the alt attribute should be empty (alt="") so assistive technologies ignore it. Alttekst should be concise and descriptive, focusing on content or function rather than layout.

Guidelines: For simple images, provide a brief description, such as "Een appel op een bord." For complex graphics, offer a short alt text plus a longer description in nearby text or via aria-describedby. Avoid phrases like "afbeelding van" and avoid irrelevant details or keyword stuffing. Use the same language as the surrounding content.

Markup example: <img src="appel.jpg" alt="Een rij appels op een markttoonbank">. If the image is decorative, use an empty alt attribute: alt="".

Impact: Alttekst supports accessibility compliance and contributes to image indexing by search engines. It should be maintained and updated to reflect changes in the image or its context.

Related topics include WCAG guidelines and the HTML img element.