To display alternative text for an image, enter the ac:alt attribute in the ac:image element as follows..Keep the alt text fairly short, as Confluence truncates long alt text entries.
<ac:image ac:alt="caDSR logo">
Positioning alt text
Confluence deletes the alt text if you spell or punctuate it incorrectly. For best results, you should also insert it as shown above, right after ac:image
.
An image inserted this way has alt text, as would be evident with the following image to one using a screen reader.
You can also add alt text by inserting the image using wiki markup. Refer to inserting an image on a page and changing the size.