Interaction Design

Web Content Accessibility Guidelines
Universal Standards

Image: Close up of a computer screen with windows displaying code.


The internet is a universal technology that is an integral part of modern life around the world. All information and tools on the web should be accessible to everyone and need to be compatible with various assistive technologies. In this section, we will look at how standardized guidelines such as the Web Content Accessibility Guidelines (WCAG) play a role in creating customizable and accessible web experiences for all users. Understanding the history of the WCAG and how it has evolved along with technology will help you understand the key considerations of accessible web design and development.

Developing an Understanding

The Web Content Accessibility Guidelines (WCAG) are a set of international standards for web developers and designers which were established by the World Wide Web Consortium (W3C) opens in new window in 1999. In consultation with a global community of digital experts, W3C aims to establish a single standard for web content accessibility that meets the needs of individuals, organizations and governments internationally (W3C, 2021).

W3C defines web content as the information contained on a web page or web app which can consist of images, text and sounds along with the markup to define the presentation of the information.

Given the global nature of the internet, a single standard creates predictable web experiences for all users. The video below is a short introduction to web accessibility and how it affects various user’s abilities to access information.


The WCAG was first published in 1999 and is comprised of four core principles and 12 guidelines that are recognized as industry best practices. Since WCAG 1.0, W3C has since released two other versions (WCAG 2.0 & 2.1) with a third in development (WCAG 2.2). Due to the rapid advancement of communication technology the guidelines need to be updated to reflect the current digital landscape. With every revision, the core principles remain the same, however the guidelines will change to address barriers related to the technologies and devices.

WCAG 2.1 Highlights

WCAG 2.1 is revision of WCAG 2.0 which maintains the principles and guidelines but adds 17 new success criteria (Deque opens in new window, 2021) that benefit individuals with cognitive and learning disabilities, users with low vision, and all mobile users (3Play Media opens in new window, 2021).

Some of the key revisions include:

  • Colour contrast required for visual controls – not just text
  • Orientation of the page is not restricted to a single display
  • Touchscreen gestures don’t require more than one finger (pointer)
  • Button and input sizes are large enough for all users

— Adapted from W3C – What’s new in WCAG.21 opens in new window

To further understand the WCAG and how barriers to access on the web can be avoided you can review the complete WCAG guidelines online. W3C also provides case studies and tutorials to further help you understand how to make use of the WCAG.