Accessibility and SEO: the need for Alt Text

Adding images to web pages makes them easier to read by breaking up text and illustrating a point without the need to use a thousand words.  However, unless you provide an adequate description of the image, your visual aid will be no help to people with visual impairment.  The paradox is that, for them, the lack of words is a barrier.  You can solve this issue very easily and, as a bonus, you will improve your site’s search rankings.

When a picture is not worth a thousand words

Let’s take a closer look at the problem.  To explain it, here is Marc Sutton from the University of California San Francisco, IT Department, who uses a variety of adaptive technologies, including a screen reader, to interact with computer systems.  Cue video …

This is an excerpt from a longer video called Screen Reader Demo for Digital Accessibility” that you can view here.

The field that Marc describes is the Alt text attribute that can optionally be included inside an <img> tag if you’re creating HTML content.

<img src="smiley.gif" alt="Smiley face" height="42" width="42">

In WordPress the Alt text is an attribute of items in the Media Library and is added here:

Screenshot from WordPress Media Library, showing how Alt text is added to increase accessibility

And the text I added to this image was “Screenshot from WordPress Media Library, showing how Alt text is added to increase accessibility.

Adding Alt text is not difficult.  You just need to develop the habit of always doing it when you add an image link, while the image subject is fresh in your mind.  If you have a “page readiness” checklist that you use before you make a page live, add a “Check all images have Alt text” item to it.

Search Engine Optimisation

So, Alt text helps the visually impaired user Image with link to Hobo SEO servicesunderstand your page better, which is a good thing.  But there’s another upside to it one which is completely unrelated to the problem we were trying to solve but which gives us a big benefit for no more additional effort. 

Search engine bots don’t see images either, but they do see the Alt text and use it to better understand and index your site, which will lead to better ranking and more visits.  16 words is a sensible limit according to hobo.  Beyond that the search engine may discard the text.

Improved accessibility and searchability using a common solution.  I’ll have some of that.1



  1. Now I need to trawl my sites to add Alt text to existing images.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>