The Web Content Accessibility Guidelines (WCAG) are the international standards for website accessibility. The World Wide Web Consortium (W3C), the standards organization for the Web, maintains the WCAG. The latest version of the WCAG is version 2.


The Web Content Accessibility Guidelines are organized around four basic principles. To help you remember these principles, you can use the acronym POUR:

  • Perceivable: this principle refers to accommodations that address sensory disabilities such as blindness and/or hearing impairments. These accommodations include the use of alternative text for images and captions for video and audio files. The use of alternative text makes content presented in images accessible to screen reading software used by those who are visually impaired, while the use of captions addresses the needs of people who have hearing impairments.
  • Operable: this principle covers keyboard accessibility. Accessible websites should not require the use of a mouse. Someone with a motor impairment who can only use the keyboard should still be able to interact with a website if it follows this principle.
  • Understandable: this principle addresses the needs of people with cognitive disabilities. To incorporate this principle into your website, you should avoid the use of jargon. You should also organize your content by using headings to divide it into more manageable sections.
  • Robust: a website is robust if it has been validated against one of the standards. This ensures that the website will work with the widest range of web browsers and other assistive technology that follows these standards.

The WCAG have several success criteria that allow you to determine how well your website follows the guidelines. These success criteria are organized into three different levels:

  • Level A: this level includes minimal accessibility features and for that reason should be avoided in favor of the other levels.
  • Level AA: at this level, the website will be accessible to most users under most conditions. This is the level supported on most websites that incorporate web accessibility principles.
  • Level AAA: this level refers to accessibility enhancements that address more specific needs. Because it is more difficult to maintain, this level of accessibility is not as common on the Web today.

The documentation for the Web Content Accessibility Guidelines can be difficult to understand because it is targeted at a technical audience and includes a lot of jargon. However, there are several websites on the Web that do a good job of presenting the same information in a more accessible way:

  • Even Grounds (www.evengrounds.com/wcag-tutorial): Even Grounds is a web accessibility consulting company that has created a useful WCAG tutorial for its clients and the general public.
  • WebAIM (www.webaim.org/standards/wcag/checklist/): Web Accessibility in Mind is a non-profit group dedicated to education efforts related to web accessibility. On the WebAIM website, you can find a checklist that can help you learn more about the WCAG, as well as conduct a step by step check of your website to see how well it meets the guidelines.
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