What are the WCAG (Web Content Accessibility Guidelines)?

The WCAG are an international technical standard published by the World Wide Web Consortium (W3C) for accessible web content. They define guidelines and success criteria that ensure websites and apps can be used by people with disabilities.

What conformance levels do the WCAG define?

The WCAG define three conformance levels: Level A covers minimum requirements, Level AA is the legally required minimum in the EU, and Level AAA is the highest level. Laws such as the European Accessibility Act generally require Level AA compliance.

What principles are the WCAG based on?

The WCAG are based on four principles: content must be perceivable, operable, understandable and robust. The individual guidelines and success criteria that companies must meet are derived from these principles.

How can WCAG conformance be tested?

WCAG conformance can be checked with automated tools such as Lighthouse, WAVE or easyMonitoring. These test colour contrast, alternative text, keyboard operability and semantics. Manual testing with screen readers is also required, as not all criteria can be measured automatically.

Are the WCAG legally mandatory in the EU?

Yes. The European Accessibility Act and its national implementations require many companies to comply with WCAG 2.1 Level AA. For public sector bodies, additional regulations based on the WCAG apply across EU member states.

WCAG – The Guidelines for Accessible Web Content

The WCAG (Web Content Accessibility Guidelines) are the globally authoritative standard for digital accessibility. Published by the World Wide Web Consortium (W3C), these guidelines define how web content must be designed so that it can be used by people with disabilities and impairments. They form the technical foundation for nearly all national accessibility laws for the web.

The WCAG address everyone who develops or operates websites, apps and digital documents. The goal is to provide content in a way that makes it perceivable, operable and understandable regardless of a user's abilities – whether via keyboard, screen reader, voice control or mouse. The guidelines function as a living framework that evolves alongside technical developments.

Across the EU, the WCAG are no longer a voluntary standard: the European Accessibility Act (EAA) and its national implementations require many companies to comply with WCAG criteria. To meet the requirements of the WCAG, businesses should understand the current version and the relevant conformance levels.

WCAG at a Glance

✓ Publisher: World Wide Web Consortium (W3C)
✓ 4 principles: perceivable, operable, understandable, robust
✓ 3 conformance levels: A (minimum), AA (legal standard), AAA (optimal)
✓ Legally relevant: Basis for the EAA and national accessibility laws
✓ Applies to: Websites, apps, online shops, digital documents

The Four Principles of the WCAG

All WCAG guidelines fall under four overarching principles that together form the foundation of accessible web content. Each principle is broken down into concrete success criteria that companies must test and meet.

✓ Perceivable: Content must be perceivable through different senses – e.g. through text alternatives for images and graphics and sufficient colour contrast
✓ Operable: All functions must be usable via keyboard; navigation and buttons must be reachable without a mouse, and flashing animations limited to prevent seizures
✓ Understandable: Text, forms and error messages must be clear and understandable in plain language
✓ Robust: Content must work reliably with different browsers, devices and assistive technologies such as screen readers

Conformance Levels: A, AA and AAA

The WCAG define three conformance levels that reflect the degree of accessibility achieved. Each higher level includes the requirements of the lower ones.

✓ Level A: Basic minimum requirements – without these, content is entirely inaccessible to many users
✓ Level AA: The minimum required by EU laws such as the EAA – e.g. defined contrast ratios and adjustable font size
✓ Level AAA: The highest level of accessibility, which cannot be fully achieved for all content

Implementing and Testing the WCAG in Practice

Implementing the WCAG starts with semantic HTML: correctly structured headings, meaningful labels for forms, sensible ARIA attributes and alternative texts for images. Interactive elements such as buttons must be reachable via keyboard navigation, error messages clearly worded and contrast ratios sufficiently high.

A range of tools is available for testing conformance. Automated checkers such as Lighthouse or WAVE quickly test technical criteria but only cover part of the requirements. For a complete assessment, manual tests with screen readers and keyboard are essential – for example to evaluate navigation, focus visibility and the real user experience. A structured, recurring check provides clarity about your progress and documents conformance.

SiteCockpit Solution

easyMonitoring: Automatically Check WCAG Success Criteria

With easyMonitoring, you continuously test your website against the WCAG success criteria at Level AA. The tool checks colour contrast, missing alternative texts, keyboard operability and semantic structure, scores your pages on a scale from 0–100 and provides concrete hints for every issue found. This keeps the progress of your WCAG conformance in view at all times.

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Frequently Asked Questions about the WCAG

What does the abbreviation WCAG stand for?

WCAG stands for Web Content Accessibility Guidelines. They are published by the World Wide Web Consortium (W3C) and are the international standard for the accessibility of digital content.

Which WCAG version is currently relevant?

EU law usually requires WCAG 2.1 Level AA. The later WCAG 2.2 adds further success criteria, for example for better keyboard operation and for users with motor impairments. Companies should follow the version that is legally binding in their jurisdiction.

Is an automated checker enough for WCAG testing?

No. Automated tools such as Lighthouse or WAVE only detect part of the criteria, such as contrast or missing attributes. Many requirements – such as the understandability of text or sensible screen reader operation – require additional manual testing.

Do the WCAG also apply to online shops and apps?

Yes. The WCAG apply to all web content, including online shops, mobile apps and digital documents. E-commerce companies in particular are required by the EAA to make their shops WCAG-compliant in order to avoid barriers for users.

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Does your website meet the WCAG criteria at Level AA? With easyMonitoring, you can automatically test your content against the relevant success criteria and receive a detailed report with concrete recommendations and next steps.

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WCAG – Web Content Accessibility Guidelines