Accessibility

The reference is WCAG 2.2WCAGWeb Content Accessibility Guidelines: the W3C standard for accessible web content, currently version 2.2. Laws and public standards usually require its level AA.In the glossary, the Web Content Accessibility Guidelines of the W3C, in their current version of December 2024. They rest on four principles, perceivable, operable, understandable and robust, and turn them into testable success criteria at three levels, A, AA and AAA. Level AA is the one laws and public standards refer to.

Text needs a contrastContrastThe luminance ratio between text and its background, from 1 to 1 up to 21 to 1. WCAG 2.2 requires at least 4.5 to 1 for normal text and 3 to 1 for large text.In the glossary ratio of at least 4.5 to 1 against its background, large text (from 18 point, or 14 point bold) at least 3 to 1. Every function must work with the keyboard alone, and the focus must stay visible and never get trapped. Images that carry meaning need a text alternative, the alt textAlt textA short text alternative for an image, written in its `alt` attribute. Screen readers read it aloud and search engines use it; purely decorative images get an empty one.In the glossary a screen readerScreen readerSoftware that reads the content of a screen aloud or sends it to a braille display. It depends on headings, labels and text alternatives in the code.In the glossary reads aloud. New in version 2.2: click and touch targets measure at least 24 by 24 CSS pixels, or keep enough space around them.

The World Health Organization estimates that 1.3 billion people, about one in six, live with a significant disability. Many more are limited for a while, for example by a broken arm or by sunlight on a phone screen. Barriers are common: the WebAIM Million found detectable WCAG failures on 95.9 percent of the one million most visited home pages in February 2026. Low-contrast text appeared on 83.9 percent of them, images without alt text on 53.1 percent. Clean headings, labelled buttons and alt text also make a page easier for search engines and AI assistants to read.

In the EU, the European Accessibility Act has applied since 28 June 2025 to services sold to consumers, such as e-commerce, consumer banking and passenger transport. It also covers providers outside the EU that offer these services to consumers in the EU. Microenterprises that provide services, with fewer than 10 employees and no more than EUR 2 million in annual turnover, are exempt.

In Switzerland, the Disability Equality Act (BehiG) obliges the federal administration to make its online services accessible, and its standard eCH-0059 requires WCAG 2.1 at level AA. Private companies that serve the public must not discriminate against people with disabilities, but the law in force sets no technical web standard for them (as of 10 November 2026). A partial revision that the Federal Council sent to Parliament in December 2024 would oblige providers of services open to the public, digital ones included, to make reasonable accommodations in individual cases; it is still under way.

Automated tests find only part of the barriers, and WebAIM stresses that a page without detected errors is not necessarily accessible. A manual pass belongs to every launch: through the whole page with the Tab key, with a screen reader, at 200 percent zoom and on a narrow phone screen. Contrast is decided with the brand colours, so it is cheapest to check before the design is final. Movement should stop when the device is set to reduce motion, which browsers report through prefers-reduced-motion. The basics also include headings in order with one main heading per page, a label on every form field and the language of the page declared in the code.