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Knowledge

Understand accessibility. No jargon.

What WCAG requires, what the European Accessibility Act regulates and how to fix common issues. Written by people who test websites every day.

Four principles, 55 criteria

  • 1. Perceivable 20 criteria
  • 2. Operable 20 criteria
  • 3. Understandable 13 criteria
  • 4. Robust 2 criteria

Every criterion explained

Sections

  • Criteria encyclopedia

    All 55 WCAG 2.2 A and AA criteria: what they mean, who they help, common failures and code to fix them.

  • Law: EAA, EN 301 549, national laws

    Who is affected, which deadlines apply and who enforces. With a table of all EU countries.

  • Glossary

    From ARIA to target size: the key terms in a sentence or two.

  • Component patterns

    Seven building blocks as live demos: what ARIA and the keyboard require, code to reuse.

  • Free tools

    EAA check, statement generator, contrast checker, checklists.

Guides: build and test

  • Forms that everyone can complete

    Forms are where people buy, book or give up. This guide shows how labels, required fields and error messages need to work for keyboard, screen reader and magnifier users.

  • Getting there without a mouse

    Many people use the web without a mouse: with a keyboard, switches, voice control or a screen reader. Here is what has to work for them and how to manage focus properly in modern web apps.

  • Contrast that everyone can read

    Pale grey text may look refined, but many people struggle to read it, and on a phone in bright sunlight everybody does. Here are the ratios WCAG 2.2 sets and how to lock them into your design.

  • The right alt text in five questions

    Good alt text replaces what an image does on the page, not just what it shows. Five questions lead you to the right answer for every image.

  • Your first screen reader test in 30 minutes

    A screen reader shows without mercy whether your page is built properly. This guide lets you test your key pages yourself, with free tools and no prior experience.

  • Cookie banners that lock no one out

    The cookie banner is often the first thing visitors meet, and for some the last: if it cannot be used with a keyboard or screen reader, the site is closed to them. Here is how to get it right.

  • Stop spam without stopping people

    A CAPTCHA is meant to stop bots and often stops people instead: those who are blind, have low vision, are hard of hearing or find puzzles hard. There are better ways to fight spam.

  • Accessible PDFs: what really matters

    Forms, price lists, annual reports: many sites publish key content as PDF. Those files must meet the same requirements as the pages that link to them.

  • Accessible video: captions, audio description and the player

    A video only reaches people who can both see and hear it, unless you add captions, audio description and a player everyone can use. This is what WCAG asks for.

  • Why an overlay widget does not make your website accessible

    Paste one script, a small icon appears, and your site is “accessible”. That is the promise. The evidence says otherwise. Here is why, and what actually works.

Component patterns with live demos

Accordion, tabs, dialog and more to try out, with ARIA, keyboard and code.

See all patterns

Guides: law and proof

We follow our own advice