Image Accessibility Best Practices

Published on March 21, 2024 • 9 min read

Making your website's images accessible isn't just about compliance—it's about ensuring that all users, regardless of their abilities, can fully engage with your content. This comprehensive guide will walk you through essential image accessibility practices that benefit everyone.

Why Image Accessibility Matters

Accessible images are crucial for:

• Screen reader users who rely on text alternatives
• Users with slow internet connections who may disable images
• Search engines that use image descriptions for indexing
• Users who may have difficulty distinguishing colors

Essential Alt Text Best Practices

Alt text is the foundation of image accessibility. Here's how to write effective alt text:

• Be Descriptive but Concise:
  <img src="sunset.jpg" alt="Orange sunset over mountain peaks reflecting in calm lake"> <img src="IMG_001.jpg" alt="image">
• Context Matters:
  • Consider the image's purpose in the content
  • Include relevant details only
  • Avoid redundant phrases like "image of" or "picture of"

Decorative Images

Not all images need alt text. For decorative images:

Use empty alt text when:

• The image is purely decorative
• The image content is already described in nearby text
• The image serves only a design purpose

Complex Images and Charts

For complex images like charts and infographics:

• Use Detailed Descriptions:
  <figure> <img src="sales-chart.png" alt="Bar chart showing sales growth"> <figcaption>Quarterly sales growth from Q1 to Q4 2023, showing 15% increase</figcaption> </figure>
• Provide Text Alternatives:
  • Include data tables for charts
  • Offer detailed text descriptions
  • Consider interactive alternatives

Responsive Images and Accessibility

Make responsive images accessible by:

• Using Appropriate Markup:
  <picture> <source media="(min-width: 800px)" srcset="large.jpg"> <source media="(min-width: 400px)" srcset="medium.jpg"> <img src="small.jpg" alt="Product description that works for all sizes"> </picture>
• Maintaining Context:
  • Keep alt text consistent across versions
  • Ensure readability at all sizes
  • Test with screen readers

Color and Contrast Considerations

Ensure images are accessible to users with color vision deficiencies:

• Use sufficient color contrast
• Don't rely on color alone to convey information
• Provide patterns or textures as alternatives
• Test with color blindness simulators

Technical Implementation Tips

Follow these technical best practices:

• ARIA Roles and Labels:
  <div role="img" aria-label="Description of composite image"> </div>
• Loading Strategies:
  • Use loading="lazy" appropriately
  • Provide fallback content during loading
  • Consider reduced motion preferences

Testing and Validation

Regularly test your images for accessibility:

• Use screen readers to verify alt text
• Check color contrast ratios
• Validate markup with accessibility tools
• Test with keyboard navigation

Common Mistakes to Avoid

Watch out for these accessibility pitfalls:

• Using generic alt text (e.g., "image")
• Embedding text in images without alternatives
• Ignoring decorative images
• Forgetting about color contrast

Ready to make your images more accessible? Try our image converter to prepare your images with accessibility in mind.

Conclusion

Image accessibility is not just about compliance—it's about creating an inclusive web experience for all users. By following these best practices, you can ensure your images are meaningful and accessible to everyone while maintaining their visual impact.