SEOs around the world reacted with smugness, with the recent news that a California judge has allowed a class action lawsuit to proceed over the use (or lack thereof) of image alt attributes. This crime against HTML validation was perpetrated by Target Corp. and is brought by an organisation representing people with visual disabilities.

Alt attributes for images are mandatory within the W3C HTML specification and are a Priority 1 checkpoint in the W3C’s Web Content Accessibility Guidelines (WCAG) . Alt attributes are essential in conveying the ‘meaning’ of images for the visually impaired through their use of talking browsers, screen readers or text only browsers. The most important consideration for SEOs is that Google strongly recommends the use of alt attributes for images.

From Google Webmaster Help

“If your site contains elements that aren’t crawlable by search engines (such as Flash, Javascript, or images)….

…. you should consider visitors to your site who are unable to view these elements as well. For instance:

* Provide alt text that describes images for visitors with screen readers or images turned off in their browsers.

Including substantially different content in the alternate element may cause Google to take action on the site.”

Alt attributes should be present within every image element in the HTML code and should describe the content of the image. For spacer images use the null alt text, alt=”", as these images offer no useful information to the user. If the image is active or performs a function, within an anchor link for example, then the alt text should describe the function. If the image is not active, but conveys information, then the alt text should contain the same information. For SEOs the alt attribute is useful as it can contain relevant keywords, however be careful as keyword stuffing alt attributes will have a very negative effect (note the Google excerpt above). Optimization of images is increasingly becoming an important factor and will have an effect within image searches, universal search (news article images, organic image results) and product search (Froogle / Google Products).

The alt attribute is one of the more neglected aspects of web site design and it will be interesting to see if web designers and developers take note of the outcome of the Target lawsuit. Depending on the success of this class action, the California courts may end up saving SEOs a considerable amount of time and energy.

Resources

W3C Validator – Check HTML validation and discover missing alt attributes on your pages.

Use the excellent Web developer browser plugin to outline images that are missing the alt attribute as you browse your pages; (not for Internet Explorer)

An accessibility checking tool will outline a web pages’ issues with accessibility, privacy and quality.