Website accessibility and the WCAG guidelines

Whether it’s a delicious cake recipe, a new product, or a helpful service, searching for information online has become part of daily life for most people. However, for individuals with visual, motor, or other impairments, digital content can often be difficult or even impossible to access. This is where the Web Content Accessibility Guidelines (WCAG) come into the picture. They serve as a standard for accessibility of websites and digital content. 

In the article “What does the EU Accessibility Act 2025 mean for your website?” we explained the EU-wide EU Accessibility Act 2025 (EAA) and explained why it is necessary for the promotion of web accessibility.  

WCAG is critical in this discussion, as it defines the specific requirements and best practices that ensure that online content is accessible to all people regardless of abilities or limitations. 

In this guide, we want to explain the WCAG guidelines in more detail and show you how they help break down barriers to create more inclusive digital spaces. We’ll show you what you need to do to make your website accessible too. 

What are the WCAG guidelines?  

The Web Content Accessibility Guidelines (WCAG) are international guidelines that define how websites and digital content can be made accessible to provide equal access for all users, including people with disabilities. They were developed by the W3C (World Wide Web Consortium) to provide web developers with clear guidance on how to create accessible online content. 

WCAG was first published in 1999 to break down barriers on the web. They offer specific recommendations on how to make websites accessible through technical design and content. For the latest recommendations and guidelines, please visit the official WCAG website of the W3C. 

Why the WCAG guidelines matter 

WCAG is critical to ensuring that digital content is accessible to all users, regardless of their skill level. They provide clear guidelines on how websites and apps are designed to be easily used by people with disabilities. This includes, for example, people with visual impairments, hearing impairments or motor impairments. 

The importance of accessibility in the digital space  

In the digital space, barriers are just as problematic as in the physical world. An inaccessible website excludes people with disabilities and prevents their full participation in social and economic life. Accessibility is thus a technical necessity as well as an essential part of social inclusion.   

The 4 WCAG principles 

The guidelines are based on four basic principles. Each principle helps identify and remove barriers that could prevent people with disabilities from using the web. These principles are: 

1. Perceptibility 

The principle of perceptibility states that information and user interfaces must be presented in such a way that they can be perceived by all users. People with various disabilities, such as visual or hearing impairments, must be able to receive the content in a form that they understand. 

Examples: 

• Text alternatives for images: Images should be provided with a so-called alt text, which provides a description of the image. This helps visually impaired users who rely on screen readers to understand the content of the images. For example: Instead of just showing the image of a ‘tree’, the alt text could be: “A green tree in the park in spring”. 

• Subtitles for videos: Videos should always include subtitles or transcripts so that even people who are deaf or hard of hearing can understand the content. For example, a video that explains a product could be captioned to reflect the spoken text of the video. 

• Colour contrasts: For users with certain visual impairments, such as colour blindness, the colour contrast between text and background is very important. The right colours also improve the user experience on a website. You can read more about this in our article about choosing the best colors for your website. 

2. Usability 

This principle requires that the user interface and navigation must be designed so they can be used by all users, regardless of ability or the choice of technology. This includes users who rely on a mouse and keyboard as well as those who use alternative input devices such as speech recognition systems or joysticks. 

Examples: 

• Keyboard accessibility: A website must be able to be fully navigated with just a keyboard so that users with motor impairments don’t have to use a mouse. All interactive elements such as forms, links or buttons should be accessible and usable by tapping the tab key or through other keyboard shortcuts. An example would be that focus highlighting for keyboard navigation is visible on every web page, so that the user knows which element he is currently on. 

• Avoidance of time limits: On websites, no interactive elements or actions should run automatically without giving the user sufficient time. For example, if a form has a deadline for entering information, there should be a way to extend or pause. 

• Avoid flickering content: Elements that blink or flicker too quickly (such as banners or ads) can put people with epilepsy or other neurological disorders at risk. Websites should avoid including these effects or offer an easy way to turn them off. 

3. Comprehensibility

This principle states that information and the user interface must be designed in such a way that they are understandable for all users. This applies to the text that is displayed on a page as well as the structure and functionality of the page. 

Examples: 

• Simple language: The language on a website should be clear and simple. Complex technical terms or sentences that are too long can be a barrier for people with cognitive impairments. A simple example: Instead of “Click here to verify your transactions” on a CTA, you could write “Confirm your transactions here.” 

• Consistent navigation: All interactive elements and navigation on the website should be consistent and predictable. For example, the “Back” button should always be placed in the same place on the page so that users know where to find it. 

• Error messages: If users make an input incorrectly, the website should display clear error messages to help them understand and correct the error. For example, “Please enter a valid email address” instead of “Error.” 

4. Robustness

The principle of robustness means that web pages must be designed to work and remain compatible on a wide range of devices, browsers, and assistive technologies, including screen readers or voice control systems. 

Examples: 

• Multi-device compatibility: Websites need to be designed to work well on desktops, tablets, and smartphones. A mobile-friendly design ensures that content is displayed correctly on all devices. A website that adapts optimally to the respective end devices is called a responsive website. With the website builder from one.com, you can easily create a mobile-optimised website. 

• Use of standard technologies: Web pages should adhere to HTML and CSS standards so that they can be interpreted correctly by different browsers and assistive technologies. A well-structured HTML page ensures that a screen reader can read the content correctly without misunderstandings. 

• Fault tolerance: Websites should be designed so robustly that they do not fail completely even in case of incorrect entries or problems with external systems. For example, a website should load correctly even if an external service such as a weather forecast is temporarily unavailable. 

These four principles – perceptibility, operability, intelligibility and robustness – form the backbone of WCAG. Upholding these standards helps ensure that digital content is accessible to everyone, making them critical for enabling an inclusive and accessible web experience. 

The 3 levels of compliance of WCAG 

The WCAG divides the requirements into three levels of compliance to ease the implementation of accessibility and to meet the specific needs and possibilities of websites.  

Each level stands for a different level of accessibility, with the highest level containing the most comprehensive requirements: 

1. Level A (minimum requirements)

Level A has the basic requirements that must be met to make a website accessible to people with disabilities in the first place.  

Examples of Level A: 

• Alternative text for images: All images must be provided with descriptive alt text so that visually impaired users using screen readers can understand what the image is. 

• Accessible forms: Forms must be correctly labelled so that they can be filled out correctly by users using assistive technologies (such as screen readers). One example would be to provide each input field with a labelled description. 

Websites that only meet Level A requirements only offer the minimum level of accessibility and many people with various disabilities may still have difficulty accessing the content. 

2. Level AA (suggested requirements for most sites)

Level AA includes requirements that are recommended for most websites. These requirements significantly improve accessibility and user experience by breaking down barriers for a larger group of users. 

Examples of Level AA: 

• Error detection and description: If a user makes a mistake while entering form data, the website should clearly display and explain that error so that the user can easily fix it. 

Most public and commercial websites should meet at least Level AA requirements, as they appeal to a wide range of users and improve accessibility for many people with disabilities. 

3. Level AAA (highest accessibility requirements)

Level AAA sets the highest accessibility requirements and aims to ensure a near-perfect user experience for everyone, including those with severe disabilities.  

Example of level AAA: 

• Complete text alternative for audiovisual media: All media content such as videos or audio files should be provided with full transcripts and subtitles to ensure access for deaf and hearing-impaired users. 

Level AAA is mainly recommended for websites that want to offer a particularly high level of accessibility, such as in the education sector or for public institutions. 

Legal requirements 

The EU Accessibility Act 2025 pursues similar goals and requires that all websites that offer certain services should follow WCAG 2.1 Level AA standards at the minimum. 

WCAG and the EU Accessibility Act (EAA) 

The EAA obliges all public bodies and private companies that are operating from or active in the EU to make their digital offerings accessible. It promotes compliance with the WCAG by making accessibility a legal obligation. 

The legal obligations imposed by the EAA 

The EAA creates clear legal obligations for public authorities and private companies. They must ensure that their websites, mobile applications and other digital offerings follow the requirements of WCAG 2.1:  

1. Setting deadlines for implementation: The EEA sets clear deadlines by which digital accessibility must be achieved. Public bodies and private companies that offer services online (e.g. online shops), must ensure that their digital offerings are barrier-free by 28.06.2025. 

2. Legal consequences of non-compliance: If the accessibility requirements are not met, heavy fines can be imposed depending on the country and the size of the company. In addition, legal action may be taken if users are unable to exercise their rights due to the lack of accessibility. In some cases, the accessibility of websites and digital offers can also be sued in court. 

3. Controls and audits: The EEA also stipulates that websites are regularly checked for accessibility, whether through self-certificates from the operators or through external audits. This ensures that the websites are still accessible and continuously improved even after the initial implementation. 

WCAG guidelines: essential for a barrier-free digital world 

The WCAG guidelines are critical to creating an accessible digital world that provides equal access to information and services for all users, regardless of their abilities or limitations. They are not only a technical necessity, but also an ethical and legal standard that has been introduced in more and more countries. 

The implementation of WCAG not only contributes to digital inclusion, but also improves the user experience for everyone. Websites that follow WCAG guidelines are more user-friendly and accessible, which contributes to a fairer society. Those who implement WCAG ensure that the Internet becomes a place that is accessible to everyone – regardless of individual needs. 

Take the opportunity to make your website accessible to meet regulatory obligations, improve your user experience, and expand your reach.