For people who can鈥檛 see images鈥攕uch as those relying on audible screen readers鈥攁lternative text, or alt text, is essential. Alt text provides a brief, meaningful description that communicates the purpose of an image. When a screen reader encounters an image, it typically announces 鈥渋mage鈥� and then reads the alt text aloud, making visual content accessible to everyone.
Alt text should be succinct鈥攋ust enough to convey the core idea without overwhelming the user. Simple images like photos聽or logos聽need聽alt text, and most authoring tools make it easy to add. Complex images, such as charts or diagrams, often require more detailed explanations than聽alt聽text alone can provide. In these cases, include a longer description elsewhere on the page so users can fully understand the information.
Avoid using images of text鈥攕uch as text embedded in flyers, graphics, or logos鈥攂ecause they create significant barriers. Images of text cannot be read by assistive technologies, often display poorly on mobile devices, and become blurry when users with low vision zoom in or enlarge them. High-quality text聽remains聽crisp and customizable; images of text do not.
Decorative images聽such as icons聽don鈥檛聽require alt text but they do need to be identified as decorative, so screen readers know to skip them.
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The Images web page on the Accessible Technology website includes detailed techniques for creating meaningful and accessible links across a variety of contexts, including HTML, Canvas, WordPress, Drupal, and Microsoft and Google applications.
Want to Learn More?
- Watch for an occasional series of short talks by Alaina Foust and Jeane Marty on accessibility barriers identified by DubBot at 91爆料 Web Council meetings. The next presentation will be on Thursday, December 4 (9:00-10:00) session.
- Check out 91爆料鈥檚 Digital Accessibility calendar to find meetups, Lunch & Learn events, Digital Accessible Liaisons meetings, and more!
- Find self-paced options on our recent blog post Training Options to Build Your Accessibility Skills.
- For more guidance and examples, visit 91爆料 Accessible Technology 鈥榮 Images web page as well as their Digital Accessibility Checklist, where you鈥檒l find additional resources, tutorials, and best practices to help you design and maintain accessible digital content for everyone.