Alt Attribute – Alternative Text for Accessible Images
The alt attribute (alt) is an HTML attribute used to provide alternative text for images. This description is displayed if the image cannot be loaded and is especially vital for screen readers, enabling visually impaired users to understand the image content.
Alternative text is a core requirement of the WCAG (Web Content Accessibility Guidelines) and essential for digital accessibility.
Why Alt Text Matters
- Accessibility: Makes visual content perceivable to blind or low-vision users
- SEO: Helps search engines understand and index images
- Fallback support: Displays meaningful content if an image fails to load
- Legal compliance: Required under laws like the ADA, BITV (Germany), or EU accessibility directives
Best Practices for Alt Attributes
- Describe the image clearly and concisely (“Loaf of rye bread on a cutting board”)
- Avoid keyword stuffing – use natural language
- Use empty alt text (alt="") for decorative images
- Don’t repeat image captions word-for-word
- Tailor to context – e.g., a product image vs. an infographic require different alt text
Example:
<img src="rye-loaf.jpg" alt="Freshly baked rye bread loaf on a wooden cutting board">You can find out more about our services in the area of digital accessibility here.
