Access for All Biweekly Tip
Not all users can see images. Many people use assistive technology like screen readers or text-to-speech software which reads the page out loud, and this software will read the alternative text instead of the image. Alternative text can also be used when a user has images turned off. The image will be replaced with alternative text.
Adding an image or a graphic to your content without using proper or empty alternative attributes (alt tags), can be extremely frustrating for people with visual impairments navigating your site through assistive technologies.
Adding alternative text for images is the first principle of web accessibility. It is also one of the most difficult to properly implement. Alternative text conveys the content and functionality of an image. It is very rarely a description of what the image looks like. When authoring alternative text, consider what the core information presented by the image is. Asking the question, "If you could not use the image, what text would you use to replace it?" is often a good test to determine appropriate alternative text.
When using image alt text, it should not include “picture of” or “image of”.
Screen readers automatically announce an image as an image. So an alternative text “Image of an apple” would be read aloud by a screen reader as “image, Image of an apple”.
Clear Reader +
Oregon State University “Alternative Text for Images”
MRWWeb Design “It’s ALT Good: Alternative Text & Accessibility”
AbilityNet “Five Golden Rules for Compliant Text”
Site Improve “Accessibility: Image Alt Text Best Practices”
Rob Carr, ICT Accessibility Program Manager
Linda Jaco, Associate Director for Sponsored Programs