WCAG 2.1: The Accessibility Standard Explained
Last updated: March 2026 · Reading time: 6 minutes
The WCAG were developed by the Web Accessibility Initiative (WAI) of the W3C to ensure that digital content is accessible to all people — regardless of disabilities or technical limitations. With the German Accessibility Strengthening Act (BFSG), they become mandatory for many digital services in Germany from June 2025.
The Four Principles of the WCAG
Perceivable. Information must be perceivable by all users: text alternatives for images, contrast between text and background, subtitles for videos.
Operable. The website must be fully operable via keyboard. No content may trigger seizures. Navigation must be logical and intuitive.
Understandable. The language of the page must be defined. Navigation must be consistent and predictable. Error messages must be helpful.
Robust. Content must be compatible with screen readers and other assistive technologies. The website must work across different browsers and devices.
Conformance Levels: A, AA, and AAA
Level A covers the most basic requirements: alternative text for images, keyboard accessibility.
Level AA is the legal standard in Germany and the EU: minimum contrast of 4.5:1, consistent navigation, error prevention in forms.
Level AAA sets the highest requirements: content in plain language, enhanced contrast, sign language for videos. Level AAA is desirable but not legally required.
WCAG Implementation in Drupal
Drupal includes accessibility as a core feature: ARIA attributes in default markup, keyboard navigation in the administration interface, and an accessibility team in the community. arocom supplements this with project-specific measures: contrast checks, screen reader tests, and manual audits.
Is Your Website Accessible?
The Future Check checks your website for WCAG 2.1 AA conformance. Or read more about our accessibility services.
Which WCAG level is legally required?
In Germany and the EU, WCAG 2.1 AA is the legal standard. The German Accessibility Strengthening Act (BFSG) makes these requirements mandatory for many digital products and services from June 2025.
What is the difference between WCAG 2.0, 2.1, and 2.2?
WCAG 2.0 appeared in 2008 and defined the foundations. WCAG 2.1 (2018) added requirements for mobile devices and cognitive limitations. WCAG 2.2 (2023) added nine additional success criteria. All versions are backward-compatible.
Does Drupal support accessibility?
Yes. Drupal has its own accessibility team and provides ARIA attributes, keyboard navigation, and semantic HTML by default. For WCAG conformance, project-specific testing and adjustments are still needed.
Read more
- Accessibility — Our services
- W3C standards — Standards-compliant code
- Reference: CJD — Accessibility in practice
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