Image Accessibility: Best Practices for Inclusive Web Design

Why Image Accessibility Matters

Accessible images ensure that everyone, including people with visual impairments, can understand and enjoy your content. Web accessibility is not only a legal requirement in many regions but also a best practice for inclusive design. Following accessibility guidelines improves usability for all users.

Alt Text: The Foundation of Accessible Images

• Descriptive: Clearly describe the image content and function
• Concise: Keep alt text brief but meaningful (under 125 characters)
• Contextual: Tailor alt text to the image's purpose in context
• No Redundancy: Don't repeat information already present in surrounding text
• Decorative Images: Use alt="" for purely decorative images

<img src="team-photo.jpg" alt="Our team of 10 smiling members in the office lobby">

ARIA Roles and Attributes

• role="img": Use for custom image elements (e.g., SVGs)
• aria-label: Provide a text label for screen readers
• aria-describedby: Reference additional descriptive text
• role="presentation": Mark images as decorative

<svg role="img" aria-label="Company logo"></svg>
<img src="decorative-border.png" alt="" role="presentation">

Accessible Image Galleries

• Use semantic HTML (e.g., <figure>, <figcaption>)
• Provide keyboard navigation for gallery controls
• Ensure focus indicators are visible
• Announce image changes to screen readers
• Include descriptive captions for each image

<figure>
  <img src="mountain.jpg" alt="Snow-capped mountain at sunrise">
  <figcaption>Mount Rainier at sunrise, Washington State</figcaption>
</figure>

Accessible SVGs and Icons

• Use role="img" and aria-label for meaningful SVGs
• Hide decorative SVGs with aria-hidden="true"
• Provide fallback text for critical icons

<svg role="img" aria-label="Search icon">...</svg>
<svg aria-hidden="true">...</svg>

Testing Image Accessibility

• Use screen readers (NVDA, VoiceOver, JAWS) to test image descriptions
• Check keyboard navigation for image galleries
• Validate with accessibility tools (axe, Lighthouse, WAVE)
• Review WCAG 2.1 guidelines for images

Common Accessibility Mistakes

1. Missing or empty alt text for meaningful images
2. Redundant or overly verbose alt text
3. Not marking decorative images correctly
4. Non-semantic HTML for image galleries
5. Inaccessible SVGs and icons

Image Accessibility Checklist

1. Write descriptive, concise alt text for all meaningful images
2. Use alt="" for decorative images
3. Apply ARIA roles and labels where needed
4. Use semantic HTML for image galleries
5. Test with screen readers and accessibility tools
6. Review and follow WCAG guidelines

Conclusion

Making images accessible is essential for inclusive web design. By following best practices for alt text, ARIA roles, and semantic HTML, you can ensure your website is usable by everyone. Regularly test your site's accessibility and stay updated with the latest guidelines to provide the best experience for all users.