Alt Text

Depending on where it appears, the alt text of the BBC's logo might be "Corporate logo of the British Broadcasting Corporation", "BBC" or a null value. In this case, it's the full text of this caption.

Alt text is an attribute of the HTML's <image> and some other tags.

It is intended to be presented when the image (or other object) to which it pertains is not available to the user, for instance in a text-only browser or a refreshable Braille display. It is also available for indexing by search engines. It is not intended to provide (though may be presented by some browsers as) "pop up" text or tooltips when a user's mouse hovers over the image.

The presence of the attribute, which may be null (alt="") is a requirement for HTML standard compliance. However (except for purely decorative images, when it should be null), the use of meaningful alt text is necessary to comply with accessibility standards; and is good practice.

Note: Alt text is commonly, but wrongly, refered to an image's "alt tag".

External links

• W3C page
• Alt text guidance from Alan Flavell
• Dive in to accessibility page on alt text
• Alt text guidelines from Jukka "Yucca" Korpela