Accessibility Glossary
WCAG criteria, patterns, and standards — with interactive demos, detection methods, and audit data.
WCAG principle 3 of 4 (POUR): content and controls must be clear and predictable, and help people avoid and recover from mistakes.
Accessible Authentication
Authentication must not require cognitive function tests (memorizing, transcribing, puzzles) unless an alternative exists. Allow paste in password fields. Support password managers. New in WCAG 2.2.
Consistent Help
If help mechanisms (contact info, chat, FAQ link) appear on multiple pages, they must be in the same relative order. New in WCAG 2.2 (Level A). Does not require providing help — only consistency when you do.
Consistent Identification
Components with the same function must be identified consistently. If 'Search' is a label on one page, don't call it 'Find' on another.
Consistent Navigation
Navigation mechanisms repeated across pages must appear in the same relative order. Don't rearrange menus between pages.
Document Language
16% failEvery page needs lang="xx" on the <html> element. Screen readers use this to switch pronunciation. Missing on 16% of homepages. One-line fix with enormous impact.
Error Identification
62% failErrors must be described in text (not just color), placed near the field, and announce via aria-describedby + role='alert'. Specific and actionable: 'Enter a valid email' not 'Invalid input'.
Error Prevention
For legal, financial, or data-deletion actions: let users review before submitting, allow undo, or confirm the action. Reduces consequences of mistakes for everyone.
Label in Name
The accessible name of a component must include its visible text. If a button says 'Search', its aria-label can't be 'Find items'. Voice control users say what they see.
Plain Language
Write so the widest audience understands on the first read: short sentences, everyday words, one idea per paragraph, and abbreviations spelled out the first time. Helps people with cognitive differences, non-native speakers, and anyone in a hurry.
Redundant Entry
Don't ask users to re-enter information they've already provided in the same process. Auto-populate or let them select previous values. New in WCAG 2.2. Helps users with cognitive and memory disabilities.