Web Accessibility: Alternative Text Descriptions
Alternative text (alt text) is one of the most important criteria of digital accessibility. This document is designed to give you basic guidance for creating alt text descriptions of graphic elements in your web pages and documents.
All content authoring tools used at Rice include ways of creating alt text descriptions, including Microsoft Word and PowerPoint, Google Docs and Slides, Drupal, WordPress, Canvas, KB, and more. This guide does not describe using any specific software, but provides a general overview of some key principles to follow when creating alt text.
- Alt text descriptions provide vital information and context for people who are blind or have low-vision and use screen readers like JAWS.
- Good alt text helps create a more equitable and equivalent digital experience for people with disabilities.
- If a web browser fails to load an image, the alt text description will still be visible, providing context and meaning for everyone.
- Alt text is searchable and improves access to content, which benefits everyone.
Alt Text Basics
Creating good alt text can seem daunting, especially when images are complex, but a few basic guidelines will help you get started.
- All images that convey information need descriptive alt text.
- Context is key. Consider why you’re using the image and emphasize what is important conceptually. In other words, describe the information, not the picture.
- Avoid starting with the words “image of” or “picture of.” Screen readers already identify images as graphics, so these words can create redundancy.
- Images that do not contribute meaning can be marked as decorative. For example, an abstract design in the header or a decorative line used to separate content. Use an empty set of quotation marks (alt= “”) to mark something as decorative.
- Try limiting your description to 125 characters (excluding spaces). For more information, check out this guide about describing complex images.
An image of the Lovett Hall sallyport might be used for different reasons. The table below gives examples of two different contexts.
“New Rice graduates gather outside of the sallyport at Lovett Hall.”
“The arch of the sallyport is two stories high. It creates a large walkway through the center of Lovett Hall.”