Alt Text

What is alternative text (alt text)? Alt text is a description of an image in the HTML code that does not appear in the text. When a screen reader comes across an image with alt text, it is read aloud to provide context to the surrounding text. This allows the reader, who may require visual assistance, to experience the book fully. If you would like a visible description of the image, you will need to add a caption.

When creating alt text:

• Avoid repeating text already stated close by.
• Decorative images do not need alt text. If images are simply added for aesthetic value and do not add to the reader experience, they can be skipped. 
  • A few examples are:
    • Ornamental flourishes, often placed at the top of a chapter page, or as a section break. 
    • Ornamental borders and dividers: Lines or frames used to style a page layout.
    • Drop Caps: Large first letter in the paragraphs on chapter pages.
• Consider what needs to be conveyed to the reader.
• What details would be missing if the image was not included?
• Avoid using text like “image of” or “picture of,”. Screen readers will provide the information to the reader it is an image. 

For example:

“A picture of a mountain by a lake.”

A better option is:

“The sun rises over a snow-capped mountain next to a frozen lake.”

To add alt text to an image already uploaded

Below is an image that was uploaded in the Book-Building Tool. You can add a:

• Caption (will show when printed)
• Photo credit (will show when printed)
• Alt text. Alt text does not show when printed, only cues screen readers to announce the description you have added with certain devices and apps.  

However, when you look at the same image in the digital preview or the PDF, you will only see the caption and photo credit.

When listening using text-to-audio, it will announce the alt text description so the reader can have the same experience a sighted reader has. 

Adding alt text using the Accessibility Evaluation

If you would like to add alt text to all images that have been uploaded you can use the Accessibility Evaluation. This option is only available in the Book-Building Tool. 

• Click on Accessibility Evaluation on the left side of the screen. 
• Click on the button Start Evaluation.
• There is instructional information on the first pop-up. 
• Click "Next" to start the evaluation. 
• The first page will list all images in the Word file that you have uploaded that are missing alt text. 
• You can add descriptive text using the tips seen above. 
• If it is a decorative element and does not add context for the reader (such as borders and flourishes), you can check the decorative column. This will tell accessible technology to skip the element. This can help the reader understand they are not missing out on any relevant information. 

There are four other sections you can proceed with that have additional recommendations for making your ebook more accessible to your current and future readers.