Why use alt image descriptions?

Using alt image descriptions (also known as alt text) is important for several reasons—both practical and ethical. Here’s why you should always include them:

1. Accessibility for Visually Impaired Users

  • Alt text is read aloud by screen readers, enabling blind or visually impaired users to understand the content and purpose of an image.
  • This is essential for making websites inclusive and compliant with accessibility standards like WCAG (Web Content Accessibility Guidelines) and laws such as the ADA or Equality Act in the UK.

2. SEO (Search Engine Optimization)

  • Search engines can’t “see” images, but they can read alt text.
  • Including relevant keywords in alt descriptions helps images appear in Google Image Search and improves your overall page SEO.
  • Properly labelled images contribute to better content relevance and context, which search engines favour.

3. Improved User Experience When Images Don’t Load

  • If an image fails to load due to a slow connection or an error, the alt text appears in its place.
  • This gives users an idea of what was meant to be shown, keeping the content understandable.

4. Better for Voice Search and AI Technologies

  • Devices like smart speakers and AI assistants rely on structured content—including alt text—for voice-based interactions.
  • Descriptive alt tags improve how your content integrates with modern, AI-driven tech.
  • Many countries require websites to be accessible to people with disabilities.
  • Failing to include alt text can result in legal action or fines, especially for businesses and public organisations.

Best Practices for Writing Alt Text:

  • Be descriptive but concise (e.g., “Golden retriever puppy playing with a ball”).
  • Avoid keyword stuffing—focus on describing the image naturally.
  • Don’t say “image of…” or “picture of…”—screen readers already know it’s an image.
  • Leave decorative images with empty alt text (alt="") so screen readers skip them.

In Summary:

Alt image descriptions enhance accessibility, SEO, and user experience, while also helping ensure legal compliance. They’re a small but crucial detail in professional, inclusive web design.