Images are not accessible. You need to add in alt text to make them accessible.
Alternative text (also referred to as alt text), is a short description of an informative image, usually about 150 characters. These are helpful for user with vision impairment, but it is also useful if a browser doesn't load the image.
Why it matters:
Sometimes your description will need to be longer than 150 characters. In that case, you may need to add this information in a caption or to the text of your document.
There are two types of images: informative and decorative.
A decorative image does not add any additional information to the accompanying text.
One example of a decorative image is an image of an apple on books with text about teachers and education. The apple and books do not add additional information to the page, and a user who could not see this image would not miss any contextual information.
Decorative images do not need any accompanying text or alt text. However, if your image is decorative, consider whether you really need to include it.
An informative image provides additional context to the content. For example, an infographic is informative. If you're not sure if your image is informative, remove the image and evaluate if any meaning is lost by removing the image. If you're still unsure, assume your image is informative.
Why you include an image on a page will change based on the page. Consider the image below. What your page is about will change why you included the image and what the viewer might take away from it. Below the image are examples of how the alt text for the image could change.
Two young children playing with blocks and other toys
Two preschool children sharing toys and playing together
Two young children playing with wooden blocks and animals
The above types are not the only types of images you may want to include in your content. Please reach out to the UXWS team if you have additional types of images (including data representations) not covered in this document and want to know how to make them accessible.