What is the WCAG?

1. Layers, layers, layers

The WCAG is made up of several layers:

• 4 principles

• 13 guidelines

• 87 success criteria

2. Different levels

In doing so, the WCAG is made up of different levels:

• Level A

• Level AA

• Level AAA

These levels are built up in ‘difficulty’. The higher the level, the more difficult it is to apply. In doing so, they are based on making websites more accessible to people with specific disabilities.

3. Different versions

Just like an iPhone (8, 10, 12, 14...), WCAG has a range of versions. Each version is a little bit better each time. For example, you have the:

• WCAG 1.0

• WCAG 2.0

• WCAG 2.1

• WCAG 2.2

• WCAG 3.0 (not published yet)

Principle 1: Perceptible

Websites should be easily perceivable by all users. Consider sufficient colour contrast of texts, and the presence of text alternatives to images.

These are the corresponding guidelines:

• Provide text alternatives for non-textual content.

• Provide a transcript for audio and video content.

• Provide video content with subtitles.

• Make sure content is logically structured.

• Use semantic (meaningful) code.

• Make sure each feature can be used when the default text size is doubled.

2. Operable

Websites should be easily operable, e.g. by keyboard, mouse, touch, voice control, a joystick or eye-tracking.

These are the corresponding guidelines:

• Make sure everything works with a keyboard.

• Show keyboard focus.

• Use descriptive titles for pages and windows.

• Use descriptive links so it is clear where it leads.

• Do not use flashing content.

3. Understandable

Websites must be understandable: the structure and texts must make sense to everyone. For example, the language of the page must also be able to be read by auxiliary software.

These are the corresponding guidelines:

• Give software the ability to determine the language of the page.

• Make the text readable and understandable.

• Make sure all form fields have visible and meaningful labels.

• Make it easy to recognise incorrect entries in forms.

4. Robust

Websites should be robust. The technology behind the website must be good and ensure that auxiliary devices can also use the website properly.

Here are the corresponding guidelines:

• Use error-free code.

• Ensure maximum compatibility with current and future browsers and other utilities.

• Make sure assistive technologies understand what each function is for and its state.

Measurable requirements

These are the actual measurable requirements that accessible content must meet. An example is the minimum colour contrast of text on a background.

Split between content and technology criteria

In our WCAG audits, we split content and technique in some situations. You can read all the criteria of the WCAG detail in our checklist.

Level A

The bare minimum that websites must meet. There are 31 success criteria at the lowest level. These are easier to apply.

Level AA

This is the desired level that websites and apps must meet according to European and Dutch regulations. There are 24 success criteria at level AA.

Level AAA

These are 31 Level AAA success criteria and are not legally required. However, they can help you make websites even more accessible to people with specific disabilities.