What is an Alternative Text?
Alternative text, commonly known as “Alt Text,” “Alt Attributes,” “Alt Descriptions,” or “Alt Tags,” is a fundamental principle of accessibility support. Alt text provides descriptive information about images, ensuring that students, staff, and faculty with visual impairments receive the same content as those who can see the image.
Writing effective alt-text is more of an art than a strict formula, as there is no single way to craft it perfectly. This guide will highlight key concepts to consider and offer practical guidance on writing clear, meaningful alt-text for accessibility.
Importance of Alternative Text and Where to Apply It
Alternative text (alt-text) plays a crucial role in digital accessibility by explaining why an image is relevant to the content. Screen reading software reads alt-text aloud, allowing users with visual impairments to understand the context and purpose of the image.
Most digital content and websites support alt-text, ensuring that descriptions remain intact when exported to HTML or PDF. To maintain accessibility, always provide clear and meaningful alt-text for the following elements:
- Shapes
- Pictures
- Charts
- Diagrams
- SmartArt
- Clip Art
- Tables
- Screenshots
- All Other Objects
How to Add Alt-Text to Images, Shapes, and Icons
- Right-click the Image, Shape, or Icon
- Select “View Alt Text…”
- Describe what the Image, Shape, or Icon represents.
In this example, you could say, “The SNHU logo.” If the image shape or icon is only decorative, then put a check mark in the box "Mark as decorative" to let the screen reader and user know that image is not important content.
How to Add Alt-Text to Graphs and Tables
- Select the entire graph.
- Right-click on the graph.
- Select "Edit Alt Text…" or "View Alt Text..."
- Explain what the graph shows in the description box.
Include information to understand the content. For this example, “The time it takes during the study for the trial to be completed. As the trials increase, also does time.”
Watch How to Make Graphs Accessible for Everyone
This video guides you through simple steps to ensure your graphs are accessible to all, including people with visual impairments. Learn best practices for color contrast, text alternatives, and screen-reader-friendly designs to make data visualization inclusive.