Image Accessibility
Image Accessibility
Images and graphics must be accessible to ensure that all users, including individuals who use screen readers or have low vision, can understand the information being conveyed. This applies to images used in Office files, PDFs, Brightspace content, web pages, presentations, and emails.
Under Title II of the ADA and WCAG accessibility standards, images that convey meaning must include appropriate text alternatives so the content is available to users who cannot see the image.
Key Accessibility Requirements for Images
Accessible images must meet the following requirements:
- Alternative text (alt text) must be provided for all meaningful images
- Alt text should convey the purpose or meaning of the image, not just describe its appearance
- Decorative images should be marked as decorative so they are ignored by screen readers
- Images containing text should be avoided when possible; important text should appear as actual text, not embedded in an image
- Charts, graphs, and complex images require longer descriptions to explain the data or relationships being shown
- Images must have sufficient color contrast and should not rely on color alone to convey meaning
- Images used as links or buttons must have alt text that describes where the link goes or what the button does
Writing Effective Alternative Text
Good alternative text:
- Is concise and meaningful, usually one or two short sentences
- Focuses on the information the image communicates
- Avoids phrases like “image of” or “picture of,” since screen readers already announce that it is an image
- Is tailored to the context in which the image is used
- Does not repeat a caption or text that already appears next to the image
Poor alt text either provides too much unnecessary detail or fails to explain why the image is important.
Examples
| Image | Poor alt text | Better alt text |
|---|---|---|
| A photo of students working in a campus greenhouse, on a page about the Plant Science program | “Image of greenhouse.jpg” | “Students tending tomato plants in the SUNY Cobleskill greenhouse.” |
| A bar chart showing enrollment rising each year | “Chart” | “Bar chart showing online enrollment increasing each year from 2022 to 2026.” Include the full data in a table or the text near the chart. |
| A decorative border or background graphic | “Orange decorative line” | Mark the image as decorative, with no alt text. |
| A printer icon that links to a printable version | “Printer” | “Print this page” |
Review automatic alt text. Word, PowerPoint, and other tools can suggest alt text automatically, often using AI. These suggestions are a starting point only. Always check that the description is accurate and explains why the image matters in your content. Grackle flags automatically generated alt text that still needs review.
Adding Alt Text
- Word and PowerPoint: right-click the image and choose View Alt Text (or Edit Alt Text). Type your description, or check Mark as decorative. Then run Grackle to check your document.
- Brightspace: when you insert an image with the Brightspace editor, enter a description in the Alternative Text field, or check the option to mark the image as decorative.
- Emails: in Outlook, right-click an image and choose View Alt Text (or Edit Alt Text).
Resources
The following resources provide clear guidance and examples for creating accessible images and writing effective alternative text:
- W3C – Images Tutorial (Web Accessibility Initiative)
- W3C – Alt Text Decision Tree: a step-by-step guide to deciding what alt text an image needs.
- W3C – Complex Images: how to describe charts, graphs, and diagrams.
- Section 508 – Create Alternative Text
- Microsoft – Everything You Need to Know to Write Effective Alt Text
- Brightspace – Insert and Edit Images with the Brightspace Editor
If an image communicates information, that information must also be available in text. Providing meaningful alternative text ensures images are accessible, supports compliance with Title II, and helps create inclusive digital content for all users.