What is digital accessibility all about?

An accessible website or mobile app is designed so that all people can use it easily, regardless of whether they have a disability. They are clearly structured, have good contrasts and are user-friendly. Barriers to accessibility can include missing alternative texts for images, a counter-intuitive heading structure or insufficient colour contrasts. Overly complex language or content that cannot be interpreted by assistive technologies such as screen readers also make it harder to use the website or app.

An internationally recognised standard, the Web Content Accessibility Guidelines (WCAG) (external Link) – describes how a website or app should be designed to be accessible.

The WCAG comprise four principles that clarify what digital accessibility is all about:

• Perceivable: The content of the website or app must be presentable to users in a way they can perceive. This means that content can be perceived even if a person lacks one or more senses, such as sight. Information-carrying images, for example, must have alternative texts and videos must have subtitles.
• Operable: Users must be able to operate the navigation and user interface components. For example, it must be possible to navigate and operate the website using just a keyboard, without a mouse.
• Understandable: The information and operation of the website or app must be understandable to users. For example, the navigation of a website or app must be standardised and input fields must be properly described.
• Robust: The content must be interpretable by different user agents, including web browsers and assistive technologies such as screen readers.

The WCAG has three levels: A, AA and AAA. Level A covers the most basic requirements, whereas Level AAA includes the most extensive and stringent requirements. Level AA lies in between. Legal requirements include conformity with Level AA of WCAG version 2.1. This is a minimum accessibility requirement, meaning that all Level A and Level AA criteria of WCAG 2.1 must be met. You can find more details about the legal requirements under "Accessibility criteria".

The WCAG already exists in a later version: WCAG 2.2. It is a minor extension of WCAG 2.1. For a future-proof approach to new web and app projects, you should aim to comply with WCAG 2.2 Level AA. If you comply with WCAG 2.2 Level AA, you automatically comply with WCAG 2.1 Level AA. The WCAG 2.2 Map (external Link) provides a visual overview of WCAG 2.2.