What are the requirements for accessible websites under WCAG and the law?

Semy WEB GbR | Jun 21 2025 - 1:09 pm CEST

What are the requirements for accessible websites under WCAG and the law?

In the previous article, we clarified what barrier-free websites are, and now it's time to understand the criteria by which a website’s accessibility is assessed and how to determine if it is being met.

Website accessibility consists of two parts: visible (visual) and invisible.

The visible part includes all settings that affect the visual appearance of the site. The invisible part includes settings that do not result in visual changes but are equally important.

Accessibility Checklist

Key Requirements for Accessible Websites (based on WCAG)

🔴 Contrast: All texts must be clearly visible and have sufficient color contrast between the text and its background — a minimum ratio of 4.5:1 (at least 3:1 for large text).
🔠 Font size: Standard text should be at least 16 pixels and easily scalable for users with visual impairments.
✏️ Alternative text: Every image used on the site should have alt text that can be read by screen readers.
📱 Responsiveness: The website should display optimally on all devices.
↕️ Keyboard navigation: All features must be accessible without a mouse, using only a keyboard.
📶 Proper site structure (HTML markup): This ensures users can navigate the page sections in a logical order.

Of course, there are many more requirements, but following these basic principles will already greatly improve the website’s usability and bring it closer to full accessibility.

WCAG Compliance Levels

Level A: Basic — e.g., alt texts and correct HTML structure.

Level AA: Required — e.g., color contrast, responsive design, labeled forms.

Level AAA: Optional, useful for special content.

Important:

A website must comply with WCAG Level AA to meet the requirements of the Accessibility Improvement Act (BFSG).

Read our next article to learn how to make your website accessible:

How to Make a Website Accessible