I recently lamented my belated discovery that “alt” text was not being displayed on mouseover of my images.
The estimable Peecay of Bibliodyssey has replied by e-mail with a description of his system:
I try to abide by the pure description (for a blind person, is how I understood it) to approximate an image with alt tag (eg. “woodcut of cat in colour from Japan, 16th cent.”)
But then I try to put something specific to the book or author or illustrator in as the title tag.
I’ve always worked under the assumption that – when including captions as well, below the image – I was priming those images as best they could be to be open to image search engines.
What I hear from the “SEO” types is that alt tags seem to help with search engines but title tags less so. That’s hearsay, really, and I haven’t tested it.
According to SearchEngine Journal, it is indeed important to keep the various tags different. Ann Smarty, speaking of the alt and title tags, says, “include your main keywords in both of them but keep them different. Keyword stuffing in Alt text and Title is still keyword stuffing.”
Wily Michael Gray has a helpful guide to optimizing images for search engines.
All good advice. But kind a lot of work to provide three different kinds of unique nonrepetitive text for all your images.