What makes a website accessible?
The answer, of course, is that a website is accessible if it is usable by all people, regardless of disability. When building a website, however, we need something a little more concrete; we need a way to test whether the website is accessible, without having to have people with a hundred different impairments actually testing it. That’s where the Web Content Accessibility Guidelines (WCAG) from W3C come in. Following the guidelines doesn’t guarantee that your website is usable for everyone, but it’s a good starting point for handling the most common accessibility issues. The guidelines help insure that all users can both access the content and navigate the website.
How important is the WCAG standard?
Many countries require that their government websites follow the WCAG standard (the US uses Section 508 guidelines, which are expected to require AA WSAG compliance, described below). Last month, a federal court ruled that having an inaccessible website is a violation of the Americans with Disabilities Act (ADA), and the Justice Department has successfully sued companies (including Carnival and Wells Fargo) over lack of accessibility (both physical and online). The ADA requires that places of public accommodation be accessible to the disabled, and websites which directly sell goods or services, or connect to physical locations which do, have been ruled to be places of public accommodation and thus subject to the ADA requirements.
How are websites evaluated?
WCAG includes three levels of compliance: A, AA, and AAA. A is the minimum level of conformance; a website that does not meet the level A requirements is simply not usable by people with certain disabilities. These are things that every accessible website MUST do. AA requirements make the website easier to use; these are things that every accessible website SHOULD do. Finally, AAA requirements are going “above and beyond” to make things easier for people with disabilities; they are things that a website MAY do. In order to claim compliance for a particular WCAG level, every part of the website must meet every WCAG requirement for that level (as well as for the levels underneath it).
What is covered?
The WCAG standard is composed of four basic principles, with a number of guidelines that lay out specific requirements for meeting those principles. The principles are:
- Perceivable. This is the most straightforward: information must be presentable to the user in a way that he or she can perceive. This includes things like text alternative for non-text content (pictures, recorded audio, recorded video), not communicating information solely by color, allowing the user to resize text, etc.
- Operable. This means that a user is able to navigate the website. This includes obvious things like being able to navigate using a keyboard alone, without losing focus, but also things like not having anything that flashes more than three times per second, which could trigger a seizure.
- Understandable. This principle at first seems more subjective; who’s to judge whether the text of a website is understandable or not? Guidelines here include that the browser can determine what language the page is in, explaining abbreviations (such as by putting the first use of the abbreviation immediately after the expanded form, as we did with WCAG and ADA above), and making the website perform in predictable ways (for example, having consistent navigation).
- Robust. The website can be interpreted reliably by a variety of user agents – this is any piece of software acting on behalf of the user, such as a screen reader. This includes things like closing tags (so that the site can be parsed correctly) and associating labels with their corresponding fields.
Because the standards include things like website navigation, the easiest way to meet them is to design in accessibility from the very beginning. Failing that, the guidelines are relatively straightforward to test for, and many of the accommodations, such as providing alt text for images, are fairly trivial to make. Even small changes like this can make a huge difference for someone trying to use your site, and many of them benefit your typically-abled users as well.