The Web Content Accessibility Guidelines (WCAG) are a set of standards and guidelines created by the Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C). The objective of WCAG is to provide a set of recommendations that will make web content accessible for all, and especially for people with disabilities.

“Web content” refers to all the information in a web page or web application, including text, sounds, images, as well as code that defines presentation and structure.


The Basic Principles of WCAG 2.0

Developed in collaboration with organizations and individuals across the world, WCAG 2.0 consists of twelve guidelines that are based on the four essential principles that websites must be perceivable, operable, understandable, and robust:

WCAG Principle 1: Perceivable

The information on a web page, as well as the user interface components, must be presented to users in a way that they can perceive it through their senses of sight, sound, and touch.

The guidelines included as part of this principle encompass the following:

  • The web page must have text alternatives for non-text content, so that it can be converted into other forms, such as audio, symbols, easier language, large print, or braille.
  • There must be alternatives for time-based media, such as audio, video, a combination of audio/video, and interactive audio.
  • All information must be available in a form that it can be presented to users in different ways, such as visuals, audio, tactile, and so on. Assistive technology must be able to determine the structure and information, so it can be rendered in other formats, such as a simpler layout.
  • Website visitors who have visual disabilities or hearing disabilities often find it difficult to separate foreground and background information. Websites must provide sufficient contrast between foreground text and the background, a clear distinction between foreground sounds and background sounds, and display text in a sufficient size for website visitors to read against a background.


WCAG Principle 2: Operable

The ‘operable’ principle of WCAG 2.0 specifies that the user interface components and navigation must be operable for all users. The following guidelines form a part of this principle:

  • People with motor disabilities, muscular weakness, injuries, and so on often find it difficult to interact with many websites using a mouse. They find that using a keyboard is much easier. This guideline specifies that all functionality must be accessible through a keyboard.
  • Many users take longer to read things on the screen or physically respond to interactivities, due to specific disabilities. They may have impaired vision, motor disabilities, or might be using assistive technologies, which could be increasing their response time. This guideline specifies that users should have enough time to read content as well as use it.
  • Users with photosensitive epilepsy react negatively to flashing visual content, which often triggers epileptic attacks. This guideline specifies that content should be designed in such a way that it does not cause such seizures.
  • People with disabilities often find it difficult to find content, determine where exactly they are, and to navigate through content. The website should be designed in such a way that users can easily determine their current location and reach the content that they would like to engage with.


WCAG Principle 3: Understandable

Website content must be easy for everyone to understand, irrespective of the disabilities they have. The ‘understandable’ principles has the following key guidelines:

  • Some users understand text directly through the visual medium, while others listen to text. There are also users who prefer graphical representations of text. This guideline specifies that all text must be understandable by users.
  • Many users prefer to have predictable patterns in terms of how information is presented to them across web pages. When functional and interactive components appear in the same location across a website, it becomes easier for visitors with disabilities to find them, and also spend less time decoding them.
  • When people interact with web pages, there are situations when they enter incorrect data or perform some other such actions that can be remedied. However, people with disabilities often find it more difficult to correct their mistakes or to even realize that they are on the wrong path. An accessible web page will reduce the probability of such errors, and will also make it clear to the user how to set things right.


WCAG Principle 4: Robust

When people with disabilities use assistive technologies, they often encounter blocks that prevent them from comfortably engaging with the content on the site. The ‘robust’ WCAG 2.0 principle specifies that the website content must be robust, thereby lending itself for easy interpretation by a wide range of assistive technologies.


Success Criteria

Under each of the guidelines listed as part of WCAG 2.0, there is a specific set of success criteria. These criteria help website developers and accessibility experts determine if a website and the pages that form a part of the website adhere to the guidelines specified in WCAG 2.0.


Legal Requirements

Businesses with a presence on the Internet should make their websites accessible to people with disabilities. Not only is it ethical, it also makes commercial sense to open up website content to a larger audience. In some countries, it also makes legal sense to make websites accessible. By adhering to globally accepted standards in the space of accessibility, organizations become more inclusive, protect themselves from lawsuits, and create opportunities for more website visitors to have comfortable browsing experiences.


Learn More

To learn more about WCAG 2.0, click here -> WCAG 2.0