The World Wide Web Consortium (W3C) is the main international standards organisation for the internet. It has developed the Web Content Accessibility Guidelines (WCAG), which have become an ISO (International Organization for Standardization) standard for making web content more accessible.

The guidelines apply to websites and to any file (eg PDF, Microsoft Word, video) placed on websites (see the WCAG 2.1 and Web Accessibility Initiative websites). Public websites managed by Australian Government departments and their agencies, universities, and other educational institutions apply WCAG.

WCAG defines accessible content as follows:

• Perceivable. The information and user interface components must be presented to users in ways they can engage with through at least 1 of their senses. For users with visual impairment, the content must be available through braille or voice recordings. Nontext content (such as images and graphics) must be described by machine-readable text alternatives.

• Operable. Users must be able to operate the website’s user interface and navigate through its structure. The structure should be logical and intuitive, with functionalities in predictable places for those with limited vision or cognitive capacity. Navigation must not require an action that the user cannot perform, or manual dexterity beyond the abilities of a person with limited hand–eye motor control.

• Understandable. Users must be able to understand the content. This means that it must be clearly written without complex language for mixed audiences. It must anticipate lower levels of literacy in those with cognitive disability, or with limited educational, social or linguistic resources.

• Robust. The content must be reliably delivered by a wide variety of user devices and systems, and in formats that can be interpreted accurately by all the standard browsers and assistive technologies, whether on computer or mobile device screens.

WCAG has 3 standards of conformance: A, AA and AAA. Each is progressively more stringent in its requirements and includes the criteria of the lower level. In WCAG 2.1 (the latest version, released in 2018):

• A represents the baseline standard, providing some basic features to facilitate accessibility

• AA provides a higher level of accessibility, and is generally adequate for most users and compatible with most assistive technologies – this is the standard targeted by Australian Government websites, and their departments and agencies

• AAA provides accessibility for the widest range of individuals with disability – this standard is important for websites designed specifically for people with disability (eg a website for users who are hearing impaired or vision impaired).

The accessibility level you target for your content will depend on your organisation and your audience. The higher standards are more time consuming and restrictive for design and content, but will be of most benefit for audiences who need accessible content.