All people are not equal. Many people using the World Wide Web have some form of disfunction, that may make using the web difficult. According to official statistics around 8 million people in the UK are disabled in some way, that is about 13% of all users having some form of disability.

There are many kinds of disability, and many of them are very mild, or have no impact on a person's users ability to use the web. However, there are many that make using the web difficult if the web site is not designed to take the disfunction into account. Possible disabilities include vision defects such as blindness or colour blindness, motor function problems, and congnitive problems.

The W3C started an accessibility initiative looking at how using existing technologies differently could improve their use by a wide range of disabled persons. The Web Accessibility Initiative came up with a broad sweep of suggestions, codified into the WAI 1.0 guidelines. Many national governments have taken these guidelines and incorporated them into laws regarding accessibility. Contrary to popular belief, the WAI guidelines do not rely on anything new, just on the sensible use of the existing technology. The guidelines do not mandate that all sites are plain and simple, or force designers to design two sites, one accessible, and one not, another common complaint of many designers. The best approach to designing an accessible site is to include accessibility in the core design goals. Trying to retrofit an exisiting site for accessibility can be complex and expensive, which is the source of complaints by many companies. For a view on UK legislation see Trenton Moss's Web Accessibility and UK Law: Telling It Like It Is.


A key design requirement for all sites should be usability. Good accessibility starts with good usability. Most current sites are have such poor usability that making them accessible is almost impossible.

If a site is being designed for usability, then the accessibility guidelines are simply a case of minor tweaking. For example using colour clues is an easy way to help users navigate a web site (usability feature); to make this more accessible, avoid colours that colour blind people can confuse. However, colours should not be essential to navigate the site, so that a blind person using a screen reader can still navigate the site.

WAI Guidelines

The actual W3C WAI Guidelines are basically a list of common sense suggestions, grouped in three levels: Priority 1 to Priority 3. Priority 1 guidelines are "must haves". These are obvious things such as full conformance to a HTML standard, all images having "alt" tags and so on. Conformance to all Priority 1 guidelines grants a site WAI single-A standard, and is the minimum that most countries now mandate in their accessibility legislation. There is no reason why any site should not reach this standard; indeed not doing so breaks the law in many countries.

Priority lists 2 and 3 add increasingly more requirements and restrictions on a web site design. Conforming to all Priority 2 guidelines grants a site WAI double-A standard, and all Priority 3 guidelines grants a site WAI triple-A standard.

Retrofitting any site other than a very basic one to the higher standards is often quite difficult, especially if it has poor usability. Building a site from scratch to triple-A standard is quite easy if it is included in the initial design goals.

Search Engines Are Blind

Good usability and accessibility benefits all users of your site, however good accessibility also has a profoundly positive impact on search engines' results. Search engines scan the web looking at billions of web pages, but the way they "view" the site is very much like a disabled person does: they ignore images and multimedia extras, and concentrate only on the text content. If your site is well designed and highly accessible, then it is likely that search engines will be able to analyse your site easily, and that you will get a correspondingly high page ranking.

A highly accessibile web site is highly search engine optimised, for example read:

Technical Details

All pages on this site are designed to pass all Priority 3 tests. One of the key design goals of this site was excellent usability for everyone.