accessiBe System
September 20, 2019

What are the Web Content Accessibility Guidelines (WCAG)?

The Web Content Accessibility Guidelines (WCAG 2.1 guidelines) are arguably the most influential protocols shaping web accessibility policy.

While WCAG was not produced by a government or regulatory agency with any power, the Guidelines have emerged as the standard for many pieces of accessibility legislation around the world.

To understand the position the WCAG holds in the web accessibility space, it’s important first to hone in on its creators, the World Wide Web Consortium, or the W3C for short. 

The W3C was founded in October 1994 at a time when global web activity was soaring. With its origins in the halls of MIT’s Laboratory for Computer Science (MIT/LCS), the founding members included some of the top scientists in the field. As of late 2019, the organization has garnered over 440 members including businesses, nonprofit organizations, universities, governmental entities, and individuals in relevant industries.  

The organization’s goals were originally focused on standardizing web protocols in order to foster compatibility and agreement among industry members. Over the years, the W3C began to place a stronger emphasis on web protocols and recommendations for systems administration. The development process for any W3C standard before it is published is quite rigorous, including draft stages, recommendations, and reviews by Consortium members. After extensive testing and analysis by the W3C community, a standard will be published, typically with three “levels” of conformance for developers or administrators who wish to label their work as W3C compliant.

The development of web accessibility standards was one of the earliest issues to be addressed by W3C founders in the mid-1990s. It would take several years however before a coherent set of standards would be published. In 1998, a 25-point document on best web accessibility practices was put forth by the Trace R&D Center at the University of Wisconsin, a collaborator of the W3C. This served as the basis for the first version of WCAG published the following year.  Almost ten years later at the end of 2008, the WCAG 2.0 was released. Today, the updated version of WCAG 2.0 is the W3C’s standard on web accessibility. 

Principles of the WCAG

While the actual articles of the WCAG are quite numerous, the Guidelines are based on four essential principles:

  • Perceivable
  • Operable
  • Understandable
  • Robust


Perceivability is all about the senses people use when browsing the web. Some users may have difficulties with one or more of their senses, making them reliant on assistive technologies. The three senses addressed by the WCAG are sight, sound, and touch. 


A website is considered operable when all the functions on the site can be activated by users with relative ease. This is especially important to consider when addressing the needs of individuals with motor disabilities. Compatibility with keyboard navigation and other mouse-alternatives play a major role in achieving operability. Avoiding setting time limits as well as mechanisms for error correction is also important in this regard.


A website must use clear terms, have simple instructions, and explain or guide complex tasks. Avoiding unusual, unexpected, or inconsistent functions are also central aspects of making a site understandable.


The robustness of a website is measured by two factors: First, a website must meet recognized standards, such as using clean HTML and CSS. Second, the site must be compatible with assistive tools disabled individuals may need to use while browsing. Maintaining a robust site minimizes the risk of users relying on technology that cannot correctly process its web pages.

How is the WCAG Related to Accessibility Laws?

Being a private international collective, the WCAG does not have any legal enforcement power in and of itself. However, several governmental bodies have adopted the Guidelines as the standards by which their own accessibility laws would be implemented:

United States

In January 2017, U.S. Access Board, the federal agency devoted to accessibility policy, approved a final rule to update Section 508 of the Rehabilitation Act of 1973. Section 508 mandates web accessibility for online platforms administered by federal bodies or any organization that receives federal funding. The new rule requires Level AA of WCAG 2.0’s success criteria to achieve compliance with Section 508. This Access Board standard came into effect in early 2018. 

Similarly, court cases concerning The Americans with Disabilities Act (ADA) (the law governing public accommodations) have also ended in courts requiring private organizations to achieve WCAG compliance

European Union

In 2010, officials adopted the WCAG’s AA Level standards as mandatory for all official sites of the European Union. This was later expanded to all “public sector” web platforms by a 2016 E.U. policy decision. Two years later, the E.U. agency that oversees digital regulations, the European Telecommunications Standards Institute (ETSI), updated the 2016 regulations to include the additions WCAG 2.1.   

The E.U. has also adopted the WCAG 2.0 for the new European Accessibility Act (EAA). The Act came into effect on 19 September 2019 and requires businesses to comply by 2025.


In June 2019, the Accessible Canada Act (ACA) was passed into law by the federal government in Ottawa. The ACA requires websites of most organizations under the auspices of the federal government to apply web accessibility standards. Parts of the private sector in the areas of banking and finance, transportation, as well as broadcasting and communications technology are also affected by this law. The official recommendations for ACA compliance state that websites should meet the standards of the “most recently ratified” WCAG. 

In addition to the federal ACA, several province-level accessibility laws have been passed in Canada over the past decade and a half. They include the Accessibility for Ontarians with Disabilities Act  (2005), the Accessibility for Manitobans Act (2013), and the Nova Scotia Accessibility Act (2017). These Acts are wider in scope than the ACA as they apply to all private organizations open to the public. All three of these laws use the WCAG as their compliance standard.     


The Australian Disability Discrimination Act (DDA) was enacted in 1992 with the goal of eliminating barriers to disabled individuals within real-world workspace. The governmental Human Rights Commission, as well as other authoritative bodies in Australia, have interpreted the DDA as applying to online services. According to official recommendations, all businesses and services in Australia are “strongly encouraged” to meet the standards of the WCAG 2.1 in order to avoid violating the DDA. 

In 2010, the Australian government launched its Web Accessibility National Transition Strategy to insure government services were accessible to disabled persons. Today, all Australian government agencies are required by law to meet Level AA of the WCAG 2.0. 


The Israel Standard (IS) 5568 came into effect on October 2017. The Standard requires nearly all businesses to make their sites accessible and is also based on the WCAG.          

To summarize

Despite the fact that WCAG has no legal authority, it has achieved global recognition as the most important set of accessibility standards and is enforced varying degrees by most major countries.

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