Creator:

Beth Callahan – Tidewater Community College, College-wide Coordinator, Office of Educational Accessibility
Sheri Prupis, Ph.D., System Office, Director, Teaching & Learning with Technology

Understanding Alt Text (Alt Tags)

An alt tag, or alternative text, is crucial to web accessibility and search engine optimization (SEO). It describes the content and function of an image on a webpage or within Canvas.

Accessibility

Alt text is primarily designed to assist visually impaired users who rely on screen readers. These tools read the alt text aloud, allowing users to understand what the image conveys. It is essential to ensure that your alt tag provides meaningful information. For instance, instead of “flag,” use “American flag flying at half-mast.”

Image Display Issues

If an image fails to load, the alt text will be displayed in its place, providing context to users about what they are missing.

SEO Benefits

Including relevant alt text can improve a website’s search engine optimization (SEO). Search engines, including Atomic Search in Canvas, use alt text to better understand the content of images, enhancing a webpage’s visibility in search results.

Adding Proper Alt Text to Images

Importance of Alt Text

Users who cannot see images depend on alternative text, often abbreviated as alt text. This short description resides behind the scenes and communicates the content of an image to individuals who cannot see it, such as those who are blind and use screen readers or Braille devices.

Guidelines for Writing Alt Text

• Conciseness: Alt text should be succinct enough to convey the idea without overwhelming the user with unnecessary detail. Screen readers typically announce “Image” before reading the alt text.
• Format Support: Alt text is supported by most document formats, including HTML, Microsoft Word, and Adobe PDF. For more information, refer to Making Images Accessible.

Collaboration Tip

If you have a lot of images (such as in science or history), consider collaborating with your department to create a shared set of images with pre-written alt text. This teamwork can reduce individual workloads and alleviate stress for faculty when accommodating students with accessibility needs. This structured format makes it easier for faculty to understand the importance of alt tags while providing actionable guidance on implementing them effectively.