HTML and CSS Reference
picture in Figure 4.1 as part of a story, I used the alt text "30 White Ibis walking across the street in front of a
Figure 4.1. A content picture
Or perhaps you've embedded a PNG of the equation in a mathematical paper, like so:
The correct alt text for this would be "The definite integral of x squared between 1 and 2 is seven thirds."
However, many times the image is not really content. It is iconographic. In this case, choose your words so that
the meaning is conveyed rather than the description. For example, on many web sites you'll see something like
<img src="right_arrow.gif" width="100" height="50"/>
The correct alt text here is not "blue arrow facing right". Instead, it is simply the word Next. This conveys the
meaning of the image better than a description could.
Finally, many images are simply decorations with no real content at all. These should have empty alt
attributes. That is, they should look like this:
<img src="bookcover.png" width="90" height="150" alt=""/>
Consider what happens when every image on your page is replaced with its alt text, because this is exactly
what happens for a blind user. The page is likely to be imperfect under these conditions, but try to make it as
sensible as possible.