Web Accessibility Standards

Websites and web-based applications are the dominant means of accessing and searching the Internet using web browsers. Website design has changed dramatically since the Internet was launched some 30 years ago. Websites became popular during the early 1990s with the newly developed publishing language, Hypertext Markup Language (HTML). Early basic websites were only text-based content and linear in the way they displayed information. Few graphics were present, and hyperlinks used to connect other web page content. The design of websites and HTML-based pages has become more sophisticated over the last 20 years with the introduction of the graphical user interface (GUI) design and artwork that could be embedded in web pages.

This development has led to an unprecedented surge in the number of users of all ages and ethnic backgrounds. Early designs did not address the special needs of persons with disabilities. The concept of digital accessibility became a major requirement to fulfil the principles of equality, justice and accessibility on which the Internet was built.

Many standards govern the design of web pages in terms of publishing languages, styles, GUI layout, and functionalities, and the use of multimedia elements, including audiovisual content. Web accessibility standards and guidelines are probably the most important and widely adopted for digital accessibility issues. They cover a wide range of disabilities, such a visual impairment, hearing impairments, voice disorders, motor skill issues, language, or learning. WCAG are considered the foundation for most nationally and internationally adopted guidelines. WCAG are built on four POUR concepts that underpin the principles for website accessibility.

The following are the main standards, guidelines and recommendations for digital accessibility:

  • W3C recommendation: WCAG 2.0;[1] the main web content accessibility standard (/ISO/IEC 40500:2012) (Arabic translation);[2]
  • W3C recommendation (June 2018): WCAG 2.1;[3] extends WCAG 2.0;
  • W3C guidelines: WCAG 2.2;[4] extended additional criteria to all compliance levels of WCAG 2.1;
  • ITU-T recommendation F.790:[5] general guidelines to standardize telecommunications equipment, associated software and services for persons with disabilities;
  • Americans with Disabilities Act Accessibility Guidelines, Section 508 Standards:[6] ensures accessible ICT infrastructure, equipment and services for persons with disabilities;
  • EN 301 549 standard:[7] a European standard that covers functional performances for diverse disabilities and generic e-accessibility requirements;
  • ISO/IEC 29138-1:2018:[8] a comprehensive international standard made up of three parts addressing user interface accessibility: part 1: user accessibility needs (TR 29138-2); part 2: standards inventory (TR 29138-3); and part 3: guidance on user needs for developers. Additional documents are included within the standard to better understand the guideline[9] and the techniques on how to implement them.[10] The conformance requirements section of WCAG 2.0 suggests three conformance levels (A, AA, AAA). Level A is the lowest level while AAA level is significantly hard to achieve. All WCAG guidelines include success criteria for web content design. Level AA has medium impact on the design when compared with A and AAA levels. While level A is not required to be visible, level AA is visible and less strict. It is considered accessible by assistive technology on all mobile devices and desktop machines.