Image metadata and search engines

Part 1 of this two part series had little if anything to do with getting your work found by search engines. There are a few extra bits and pieces of image metadata that sit outside the image file. These pieces of metadata are relevant for search engine optimisation (SEO) rather than for identification and ownership.

There are potentially three areas where information about the image can be placed outside the image file contents, and so potentially of use to search engines in identifying the content of the image. These are particularly useful for giving a hint about the subject matter to Google Images and other image directories, as technology hasn’t yet moved sufficiently far forward for search engines to be able to just look at the image itself to determine the content!

The filename

The first and most obvious is the filename itself. ‘My-beautiful-picture.jpg’ says more about the image than ‘DSC0075.jpg’ and so gives more of a hint to the search engines about the content of the page. As well as giving information about the page content to the main text search engines, it will make a larger contribution to the ability of Google Images to identify the subject matter of the image, and on an image based site Google Images can be a major contributor to visits to the site, if it correctly identifies the images.

This is something you may have some control over even if someone else is hosting your site – though they may just overwrite the name you provide with a random string. In this case there’s not much you can do.

Inside the html ‘img’ element

The img element in an html or xhtml page contains two tags that can (and should, for accessibility reasons) hold additional information about the image. These are output on text readers where full visuals are not possible.

The ‘title’ tag

The title tag should hold a title for the image. One obvious contender here is the title for the artwork, but you could include the artist’s name as well (both are useful in identifying what the page and image are about, and so useful for general and image SEO). Its likely that you will have some way of entering a title for an image, even if you don’t manage your own website, and the site managers ought to make use of this in creating a title tag.

The ‘alt’ tag

The alt tag should contain a further description of the image, so is an opportunity to tie more keywords to the image (technique, media etc.). You may not have an opportunity to provide information for this if someone else is hosting your site, but if you can, again make use of it. It is a recommended component of the image element for accessibility purposes, and mandatory for validation in some versions of xhtml.

This article was originally published, in a slightly different form, on Selected Artworks