ServiceNow Knowledge: Write Alternative Text for Images
Alternative (Alt) text is used to describe images to make them accessible to people using assistive technologies, such as screen-readers. Screen-readers read out loud page content, including any alt text.
When you insert an image in a Knowledge Base article, you must provide alternative text.
Writing alternative text (alt text)
Alt text should replicate in words what an image is communicating. If the image shows a dialog box with a highlight, the Alt text should identify both the name of the dialog box and the highlighted selection.
For example, the image below shows where to enter Alt text when inserting an image into a ServiceNow knowledge base article. The Alt text for this image is Insert/Modify Image dialog box; the Alt text field is highlighted
Using "null" alt text
If the information provided by an image is already described in the surrounding text, use null (empty) alt text. Entering the “null” alt attribute “” -- two double quote marks, no space - tells an assistive technology, such as a screen reader, to ignore the image. Otherwise, it will read both the surrounding text and the alt text which would be repetitive and distracting.
For example: if you include an image of a button and have already referenced the button in text, use the null alt text attribute.
If you use the "null" attribute, do not enter a Tooltip because it also would be repetitive.
Additional alt text examples for technical documentation
The IT department at Northwestern University has a guide for Writing Alternative Text. Page one is an excellent summary of what is important to include and what should not be included. The remaining pages contain example images for technical documentation and their corresponding alt text. You may find these examples helpful when creating your own alt text.