WCAG explained

WCAG is the rulebook for making websites usable by people with disabilities. Laws and lawyers point to it. Here's what it is, without the jargon.

Check the official rules. Rules and dates change, so check them with the official sources before you rely on them: ADA.gov (the US Department of Justice), the W3C's WCAG pages and Section508.gov. PageKiwi helps you find problems and get closer to meeting the rules. It can't promise a website meets them, it isn't legal advice, and we can't take responsibility for decisions made from it.

What it is

The Web Content Accessibility Guidelines (WCAG, said "wuh-cag") are written by the W3C, the group that sets standards for the web. They're a list of tests a website should pass, like "every picture that matters has a text description" and "everything works with a keyboard".

Versions
2.0 (2008), 2.1 (2018) and 2.2 (2023). Each adds to the one before, so meeting 2.2 meets the others too. Version 3 is being written.
Levels
A is the basics. AA adds more and is the one laws and contracts ask for. AAA is the strictest; few whole sites aim for it.
The law
The Department of Justice's rule for state and local governments names WCAG 2.1 AA. For businesses, there's no named version, but AA is what's usually measured.

The four ideas behind it

  • People can perceive it

    Pictures have descriptions, videos have captions, and text is dark enough to read. Picture Check, Alt text writer, Color check.

  • People can use it

    Everything works with a keyboard, nothing flashes, and people have time to finish. PageKiwi for Chrome numbers every Tab stop.

  • People can understand it

    Plain words, the page's language set, forms that say what they want and what went wrong. Readability.

  • It works with their tools

    Screen readers and other assistive technology (voice control, switches) can tell what each part is: labeled forms, named buttons, proper headings. Accessibility Check.

How far automated checks go

Tools like PageKiwi can test some WCAG rules completely (is there alt text? does each form box have a label?) and others not at all (does the alt text make sense? is the order logical?). Use them to clear the common problems quickly, then check the rest by hand: try the page with only the keyboard, zoom to 200%, and read the headings on their own.

The full guidelines, with a quick reference you can filter, are on the W3C's website.