Creating Accessible Excel Spreadsheets (macOS)

Updated on Apr 11, 2025

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…”

The menu from right-clicking the image. The "View Alt Text..." option is highlighted in red.

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, put a check mark in the box "Mark as decorative" to inform the screen reader and user that the 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.

The Alt Text description box with a short explanation entered in.

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, so does time.”