Web accessibility makes sure a website works with more than a mouse and a screen. Some people have pages read aloud by a screen reader, magnify content heavily, operate a website with the keyboard alone, or control it by voice. The programs and devices that help them are called assistive technologies. The World Wide Web Consortium (W3C), which develops core web standards, applies accessibility to all disabilities that affect access to the web: auditory, cognitive, neurological, physical, speech, and visual. According to the W3C, accessibility also helps older people, people with a temporary impairment such as a broken arm, users of small screens, and anyone in bright sunlight or on a slow internet connection. Accessibility is often abbreviated as a11y.

The benchmark: WCAG 2.2

What makes a website accessible is described in the W3C’s Web Content Accessibility Guidelines (WCAG). WCAG 2.2 was published on October 5, 2023, and updated on December 12, 2024; the October 2023 version is also the international standard ISO/IEC 40500:2025. WCAG organizes its requirements under four principles: content must be perceivable, operable, understandable, and robust. Below them are testable success criteria at three levels: A (the lowest), AA, and AAA (the highest). A few of them show what this means for a company website:

  • Text alternatives: Informative images have alt text that conveys their content, for example, “Blue cordless drill with two batteries and a charger” in the alt attribute of a product photo.
  • Keyboard: All functionality can be operated with a keyboard, including menus, filters, and forms.
  • Structure: What the design conveys, such as headings, lists, and tables, can also be recognized in the code.
  • Labels: Form fields have labels, and headings and labels describe their topic or purpose.
  • Name and role: Software can determine what each control is and what it is called, for example, a button named “Add to cart.”

Semantic HTML takes care of part of this on its own: a button element is a button to software without extra effort, and a label element linked to a form field gives the field its name.

What accessibility has to do with AI agents

A screen reader usually doesn’t analyze the image on the screen. It gets the information from the browser, namely from the accessibility tree, a simplified version of the page in which every relevant element appears with its role, name, and state. WCAG’s “robust” principle targets exactly this: content should be built so that a wide variety of programs can interpret it, including assistive technologies.

AI agents that complete tasks on websites on people’s behalf, such as comparing offers or booking an appointment, can use the same structure. The Chrome developer blog notes that accessibility is for humans first but that agents rely on the accessibility tree as their primary data model. A control without a name, such as a button that shows only a magnifying glass icon, is therefore an obstacle for screen reader users and agents alike.

Google’s auditing tool Lighthouse examines web pages in several categories, including “Accessibility.” Some of its audits that matter most for machine interaction, such as whether every control has a name, are also part of Lighthouse’s experimental category for AI agents (Lighthouse Agentic Browsing). This makes accessibility one of the foundations of an agent-friendly website.

Why accessibility is worth it

An accessible website can reach more people, and for some offerings, accessibility is required by law. There is also a link to AI systems that read pages as text: in Bing’s Webmaster Guidelines, Microsoft states that across Bing and Microsoft’s AI assistant Copilot, clear, accessible images and video improve reliability, citation quality, and the accuracy of grounding, which anchors answers in retrieved sources. For this, Microsoft recommends alt text, captions, and transcripts, among other things. Such text versions add to a website’s machine readability. Neither Microsoft nor Google promises that an accessible website will be mentioned or cited more often in AI answers.

Accessibility law in Germany: the BFSG

In Germany, the Barrierefreiheitsstärkungsgesetz (BFSG), often translated as “Accessibility Strengthening Act,” has applied since June 28, 2025. It implements EU Directive 2019/882, the European Accessibility Act, and requires accessibility for certain products and services, including online services through which consumers can conclude a contract, such as online stores. Microenterprises that offer or provide services are exempt. Under the law, a microenterprise has fewer than ten employees and an annual turnover or balance sheet total of no more than €2 million. According to the W3C, most organizations rely on WCAG and the European standard EN 301 549 to address the European Accessibility Act; the 2026 version of EN 301 549 is based on WCAG 2.2. Whether and to what extent the law applies to a particular website is a legal question that depends on the individual case.