Matt Cutts, a senior engineer at Google, has posted a video on how we use Alt Attributes for images (Alternative text attribute) so that search engines can better understand what an image is. Creating effective Alt Attributes for images will help images get returned in searches for images such as in Goggles image search, http://images.google.com/
Background on Image Alt Attributes
Search engines can’t read graphic images (although they are improving their ability to figure out what an image is about), but many will read the text contained in the “Alt tags’ for the images (Note as someone points out in the comments of Matt’s video, most of us in search marketing refer to them as “Alt Tags” which is incorrect. They are actually Alt attributes of the Image tag. Old habits die hard).
You’ve probably seen Alt-tags before. On most browsers if you hold you mouse over an image a little text box appears.
Alt tags or are used for the following reasons –
- Accessibility. They are read by the readers used by the visually impaired etc.
- Visitors with slow speed connections can usually read the Alt tag before the image loads and determine what the image or image link is about from the Alt tag
- Some internet users, usually those with slow speed connections, turn off image downloading and rely on the Alt tags.