What is web accessibility?
An accessible website works for people who use it differently: someone who is blind and listens to the page through a screen reader, someone with low vision who zooms in a long way, someone who cannot use a mouse and navigates by keyboard or voice, someone who is deaf and needs captions, someone with a cognitive disability who needs plain language and predictable layouts. It also works for everyone in temporary or situational versions of those conditions: a broken wrist, a bright screen in the sun, a video watched on mute.
The standard is the Web Content Accessibility Guidelines, WCAG, published by the W3C. The current version, 2.2, sets out testable criteria at three levels, A, AA and AAA, under four principles: content must be perceivable, operable, understandable and robust. Level AA is the benchmark most laws and policies refer to.
Why it matters
Why web accessibility matters
Roughly one in four adults in the United States lives with a disability, according to the CDC, and every one of them is a potential customer, reader or employee. Excluding them is a moral failure and a commercial one. It is also a legal risk: website accessibility lawsuits under the Americans with Disabilities Act are filed by the thousand every year, and the European Accessibility Act has applied to many consumer-facing digital services since June 2025. And accessible design is simply better design: clear headings, good contrast, captions and keyboard support help every visitor, and search engines read accessible markup more easily.
In practice
How web accessibility works in practice
- 01
It starts in design. Color contrast is checked against WCAG ratios, at least 4.5 to 1 for body text. Information is never carried by color alone. Focus states are designed rather than left to the browser. Type is sized to be read, layouts reflow when zoomed, and touch targets are big enough for imprecise fingers.
- 02
It continues in the build. The markup uses real headings, lists, buttons and links in a logical order, so assistive technology can make sense of the page. Every meaningful image has alt text, and decorative ones are marked to be skipped. Forms have labels, errors are announced, and everything that works with a mouse works with a keyboard.
- 03
Content carries its share. Videos get captions and, where the picture shows what the soundtrack does not say, audio description or a transcript. Link text says where it goes rather than click here. Writing is plain and well structured, and documents such as PDFs are made accessible or offered in another format.
- 04
Then it is tested, with automated tools that catch the mechanical errors and with people, ideally including disabled users, completing real tasks with screen readers and keyboards. It is checked again whenever templates change, because accessibility is usually lost one careless update at a time.
Watch out
What people get wrong about web accessibility
Believing an overlay widget solves it. Scripts that promise one-line compliance do not fix the underlying markup, are widely criticized by disabled users and have not kept sites out of court. Second, treating it as a checklist before launch, when most problems are cheaper to avoid in design than to fix in code. Third, thinking it only concerns blind people. Keyboard users, deaf visitors, people with cognitive or motor disabilities and older readers with failing eyesight all depend on it.
