The ALT attribute in an HTML element
As the search engine robots are unable to read images, the ALT attribute makes your images readable by robots by associating text with a short key phrase or key sentence.
W3C says its utility:
The ALT attribute is defined in a set of tags (ie, image and possibly for input and applet) to allow you to provide an equivalent text to your image.
A text equivalent provides benefits to your site and its visitors in the following situations:
- Nowadays, web browsers are available on a wide variety of platforms and offer very different, some can not display images, some others can not view a certain type, some can be configured to not to load images. If you use the ALT attribute in the code of your images, most of these browsers will display the descriptions you give to the place of your images.
- Some of your visitors might not see the images on your website, whether blind, color blind or have sight problems, the ALT attribute is a major lifeline to these people because they can have a good idea of ??what your web page.
- The search engine spiders belong to these two categories mentioned above: if you want your website to be indexed as it deserves, use the ALT attribute to make sure they will not avoid the important parts of your Web pages.
What should you put in the ALT attribute?
The general rule to fill the contents of the ALT attribute is to use a text that identifies the image. Specifically:
- If the image is a decorated text, rewrite the text in the ALT attribute.
- If the image is used to create bullets from a list, or a horizontal line, or other similar decorative motif, it is advisable to have empty ALT attributes (eg. ALT = “”).
- If the image has a lot of information, try to summarize in a short sentence for the ALT attribute, then add a longdesc (long description) related to a file where you place a more elaborate description.