Accessibility
Images
Last modified 9/26/2025
Images require alternative text for individuals who have visual impairments, including those who have color-blindness. Alt text is a brief textual description that serves as a substitute for images and conveys their content and purpose to individuals who may not be able to see them. By writing effective alt text, you can ensure that your website is accessible to people with visual impairments and create a more inclusive online experience.
Why is alt text important?
Support for Screen Reader Users
Alt text allows screen readers to describe images for users with visual impairments, making content more accessible and inclusive. Clear, descriptive alt text ensures that visual elements are understood by all users.
Providing Context
Alt text conveys the essential information or purpose of an image for those who cannot see it. This helps users grasp the message or context that would otherwise be lost.
Boosting SEO
Search engines use alt text to index images. Writing accurate, relevant descriptions can improve your site's visibility in search results and increase traffic.
Enhancing User Experience
When images fail to load or aren’t visible, alt text provides clarity. It helps all users—especially those using assistive tech—navigate your content more effectively and with fewer barriers.
Alt Text for images with Microsoft
Adding alt text in images Canvas
Adding alt text in images Modern Campus/ Omni CMS
In My Own Words
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Meet V, who relies on alternative text for images.
Types of Images
Information Images
Information images are images not used as a like. They are present to convey meaning or information. The alternative text foir information images should describe the image and its purpose for supporting the page content.
Action Images (links, etc)
Action images are images that have an action, such as a linked image. The alternative text for an action image should provide context for the target of the link.
Larger data
Larger data images, my not be images but other forms of non-text content such as charts and graphs. The information present in the graph or chart needs to have a text equivalent.If information is too large for an alt tag, included the data table for the chart or graph.
Text
Avoid if possible. Text embedded into image files are not accessible to some assistive technologies. Instead it is best to use HTML for text. If you must use an image of text, then use the text in the image as the alt tag, do not identify the specific image scene or elements. The text is typically the important information in a text image.
Decorative images
Decorative images do not have a significant function except for decoration. These images can have a blank or null alt text (alt=""). Please note, the OU campus editor requires all images to have an image description before they can be uploaded. In these cases, it is best to add the image description anyway.
Blinking Content
Avoid blinking content. Flashing or blinking content (particularly content in red) can cause seizures in people with photosensitive epilepsy as well as other photosensitive seizure disorders. Limit use to only when necessary. If blinking conent is necessary content should not flash more than three times in one second.
More Resources for Accessible Images
Feedback
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