# Web accessibility (WCAG)

URL: https://tnb-tech.com/en/glossary/web-accessibility/

## What is web accessibility (WCAG)?

Web accessibility is the property of a site that lets people with disabilities use it — with a screen reader, by keyboard alone, with low vision or without sound. It is measured against WCAG, a set of testable criteria at three levels (A, AA, AAA), of which AA is the usual requirement. It covers contrast, image alternatives, field labels, focus order and captions.

**Example**

An enquiry form with five fields. The labels are grey on white at a contrast of 2.8:1, where WCAG asks for at least 4.5:1 on body text. The fields have no label, only placeholder text that disappears at the first keystroke; a placeholder is not a label, and WCAG asks for a caption that stays visible while the field is filled in and checked. The error is a red border with no words, which tells a person who does not distinguish red only that something, somewhere, is wrong.

The repairs are small: contrast at 4.5:1 (3:1 for large text), a visible label above every field, a focus outline that follows the Tab key, and the error written beside the field that caused it. None of them changes the design; they change whether the form can be completed at all.

WCAG arranges its criteria under four ideas — perceivable, operable, understandable, robust — at three levels. Level A is the floor, AA is what regulation and procurement normally ask for, and AAA is stricter than most sites can hold across all their content.

**Why it matters for a business**

The people who cannot use a mouse, or who read at 200% zoom, rarely complain. They leave, and nothing in the analytics says why. The same repairs help everyone else: captions get watched without sound, high contrast survives sunlight on a phone, and a form that works by keyboard is faster for anyone filling in forms all day.

There is a legal side too. Public-sector sites have had accessibility obligations under a 2016 EU directive, and since 28 June 2025 the European Accessibility Act covers a list of private services, e-commerce among them. The European benchmark is the standard EN 301 549 — WCAG 2.1 level AA today, WCAG 2.2 in its new edition.

Contrast, labels, focus and heading structure are part of how we build pages in website development. A full WCAG audit and bringing an existing site into conformance are separate work we take on, outside a standard build.

**What to ask**

- To which level — A, AA or AAA — and against which version, WCAG 2.1 or 2.2?
- Was it checked by keyboard and with a screen reader, or only by an automated tool? Tools catch part of the criteria; the rest needs a person.
- Does every image that carries meaning have a text alternative?
- Can the form, or the order, be completed with the keyboard alone?
- Is there an accessibility statement and an address for reporting a problem?
- Who keeps new content accessible after launch?

- Services: [Website development](https://tnb-tech.com/en/services/website-development/)
- Glossary: https://tnb-tech.com/en/glossary/