Whenever you add an image to a Web page, you can use the Alternative (Alt) attribute to briefly explain the image. For instance, if you created an image for your Web page heading (so that you could use a fancy font), then you can use Alt to spell out the text. If the image you add is a photo of the Elbe River as it flows into the North Sea, you can use the Alt attribute to explain that.
Alternative text is helpful for those who surf the Internet with images turned off (which some do for quicker page loading), but alternative text is a must for the visually impaired viewers who use Web readers or other accessibility devices to read Web pages. Although they cannot see the image, their readers tell them what is written in the Alt attribute.
In our Fluffy image tag, we could add this Alt attribute: <img src=“Fluffy.jpg” width=“250” height=“120” Alt=“Photo of Fluffy on the porch”>
Many HTML editors, including Adobe Dreamweaver, ask for the Alt text any time you add an image to a Web page.
Please Note: The graphics that you use to create borders, background designs and transparent spacers should either have no Alt tags or else empty Alt tags, like this: Alt=“”. Adding a text description to these designs and “housekeeping” images produces unnecessary clutter for users of screen readers.
Using Alt attributes in your image tags is part of Section 508 Compliance.
Below, see the photo of Fluffy on the porch.
Happy Web page building!
To learn which image format is right for you, including definitions of the more common image file formats - GIF, JPG and PNG - please see part 1 of this series called Tips for Creating Website Graphics - Which Image Format is Right for You?