The Web Content Accessibility Guidelines

What is the WCAG?

The Web Content Accessibility Guidelines, or the WCAG, are recommendations written by the World Wide Web Consortium (W3C) to determine a website’s level of accessibility.

The WCAG aims to guarantee inclusivity and accessibility to all Web users while simultaneously increasing usability for all web operators. The WCAG is separated into three conformance levels: A, AA, and AAA, which allow developers to determine the site’s level of accessibility, and compliance.

What is Web Accessibility?

Web Accessibility is the level of accessibility of websites and other online tools developed for anyone using the Web, including individuals with disabilities.

Web Accessibility provides a foundation of requirements for developers and web users to practice creating websites to be inclusive of individuals with disabilities intentionally. It eliminates potential barriers for web users with auditory, cognitive, physical, speech, visual, or neurological disabilities.

What are the four principles of Web Accessibility

The four principles of Web Accessibility are:

  • Perceivable
  • Operable
  • Understandable
  • Robust

These principles serve as a guide for success. Users of the Web must provide content that includes all four principles, or else the Web will not be inclusive to individuals with disabilities.


The first principle of Web Accessibility is “Perceivable.” This principle means that information on the Web must be presentable and easily understood by the user.

Perceivable information should be appealing to the senses and, therefore, inclusive to all levels of ability. For example, text alternatives, such as large print, text-to-speech, or symbols, make the user interface easily perceivable to someone with a visual or an auditory disability.


The second principle is “Operable,” or navigable. Users must be able to navigate interfaces and their functions with ease.  

Operable sites are keyboard accessible and provide the user with enough time to read content without being interrupted. They allow for input on the site through keyboard usage, and they are conscious of creating content that would trigger a physical reaction from a user. Operability is vital to Web Accessibility as it provides universal usability and inclusivity on a laptop, desktop, and mobile devices.


The third principle of Web Accessibility is “Understandable.” All information and functions belonging to an interface must be understandable to the user.

Text content must be readable by users with disabilities and assistive technologies, while landing pages should function in a predictable manner, such as provide a navigation bar. For sites to be Understandable, they should also offer input assistance, better error messages, and help to prevent errors.


The final principle of Web Accessibility is “Robust.” The term robust refers to content that can be interpreted by a wide variety of users, as well as assistive technologies. Regardless of technological advancement, content should remain consistent and accessible to the user.

What does WCAG apply to?

The Web Content Accessibility Guidelines apply to any type of digital content. This content includes applications, websites, and other user interfaces. The WCAG is an international standard that web developers across the globe agree to comply with.

Is WCAG required?

Actual compliance with WCAG varies from industry to industry. Private businesses are not required by law to comply with the WCAG guidelines, but federal agencies and their contractors are. Private companies have a responsibility to have accessible websites due to the Americans with Disabilities Act (ADA) that dates back to 1990. There is no specification of a technical standard such as the WCAG mentioned in the ADA; therefore, they are not considered in violation if the site does not meet the WCAG’s standards.

While this is not a technical violation, courts have begun to require reasonable accessibility of private business sites through WCAG standards.

How can I get WCAG certified?

There is a growing need for professional web developers and designers with a background in web accessibility due to the increased global usage of the WCAG.

Individuals must complete the Web Accessibility Specialist Exam to become a Web Accessibility Specialist (WAS). The WAS exam is 75 multiple choice questions and a two-hour exam with questions from both the WCAG 2.0 and WCAG 2.1.

Web Accessibility Specialists must earn 35 Continuing Accessibility Education Credits (CAECs) every three years to maintain certification.

What are the three Conformance Levels of WCAG?

The three testable success criteria levels of the WCAG are Level A, Level AA, and Level AAA. The level of compliance depicts the accessibility of a site according to the WCAG 2.0.

Level A

Level A classification is the bare minimum a site can be considered accessible. It is the minimum level of conformance to the WCAG. This level signals that the site has conformed to the WCAG requirements or has an alternate version available for individuals with disabilities. Conformance is only possible by meeting all of the Level A success criteria.

Level AA

The second level of conformance is AA. This level signals that the website meets all of Level A’s criteria and Level AA’s. The difference between Level A and Level AA is that a site must conform entirely under Level AA versus a part of the site or a page in Level A. Most websites will conform to Level AA success criteria.

Level AAA

The third level of conformance is AAA. Level AAA conformance signals that a web page has satisfied Level A, Level AA, and Level AAA criteria. Fewer websites will conform to Level AAA because not all web content can meet all Level AAA success criteria.

What are the WCAG 2.1 Guidelines?

The Web Content Accessibility Guidelines (WCAG) 2.1, developed in June of 2018, expand on the first set of W3C recommendations and WCAG 2.0 guidance published in December 2008.

In the WCAG 2.1, criteria regarding mobile users and users with vision, cognitive, and learning disabilities were added. The W3C recommends the use of WCAG 2.1 resources when compared to WCAG 2.0 as it contains the most current version of the WCAG.

The WCAG 2.1 should be utilized by developers when updating a site’s accessibility policies or designing a new site. The Web Content Accessibility Guidelines continue to increase the accessibility and reachability of all individuals, including those with disabilities.

How does the WCAG apply to HTML?

HyperText Markup Language (HTML) is the coding used to design web pages and display content. The Web Content Accessibility Guidelines apply to HTML as they are the standard for proper web design, functionality, and accessibility.

If a site is not coded to the WCAG standards, the site will not be fully accessible. The W3C has created a set of “Easy Checks” that can be performed to determine a site’s accessibility level.

These checks will verify your site covers accessibility issues such as:

  • captions on audio and video content
  • alt-text for images
  • screen reader, mouse, and keyboard accessibility
  • minimum levels of color contrast between graphics and user interface components
  • minimum levels of color contrast between text and background

What is the future of WCAG?

Technology has rapidly intertwined with society and will continue to do so in unimagined ways. As technology and society advance, the need for fair practice does as well. A major concern of the W3C is a consistent, short timeline for revisions to the WCAG. They have expressed their concern for a shortened space between revisions and have vowed to publish updates between eighteen and twenty-four months going forward.

Another major change coming to the WCAG is its title. Instead of the WCAG, the next update will be named Silver as the initial “Web” title is not inclusive of other internet-powered tools. It is expected that the W3C will publish the new success criteria in 2021.


An estimated 1 billion people live with disabilities globally, so the Web Content Accessibility Guidelines play a vital role in ensuring the inclusivity of all individuals using the Web.

The WC3 recommends the WCAG 2.1 guidelines to all developers, web designers, and other stakeholders. The WC3 believes that everyone in the technology industry should adopt  WCAG compliance as common practice to ensure site accessibility.

Skilled Web Accessibility Specialists are in growing demand as technology expands. With this in mind, we can be hopeful that the expansion of knowledge surrounding the WCAG will lead to a more inclusive online environment and set of standards that will be widely adopted and practiced worldwide.

Visit Compliant for help building a WCAG checklist for your website.