The internet has become a part of daily life, but not everyone uses it in the same way. Web Content Accessibility Guidelines (WCAG) are a set of formal standards aimed to address this problem.
Conform to WCAG and make your website accessible to everyone, regardless of their abilities or the way they navigate it.
The 4 principles (P.O.U.R.)
WCAG consists of 4 high-level principles. Each principle is broken down into a number of sub-criteria.
1. Perceivable
- Text Alternatives (1.1): Provide text alternatives for non-text content.
- Time-based Media (1.2): Provide alternatives and captions for multimedia content.
- Adaptable (1.3): Present content in different ways without losing information or structure.
- Distinguishable (1.4): Ensure content is readable, with sufficient color contrast and text sizing options.
2. Operable
- Keyboard Accessible (2.1): Ensure all functionality can be operated via a keyboard.
- Enough Time (2.2): Provide users enough time to read and complete tasks.
- Seizures and Physical Reactions (2.3): Do not design content that is known to cause seizures or physical discomfort.
- Navigable (2.4): Create a navigable and intuitive user interface.
- Input Modalities (2.5): Ensure compatibility with input methods beyond just a keyboard.
3. Understandable
- Readable (3.1): Make content readable and understandable.
- Predictable (3.2): Create a consistent and predictable UI.
- Input Assistance (3.3): Help users avoid and correct errors.
4. Robust
- Compatible (4.1): Optimize compatibility with current and future technologies.
Key terms
The following are some key concepts that can help make WCAG easier to understand.
- WCAG versioning - The guidelines are updated at irregular intervals so it's important to be clear which version you're referencing. E.g. WCAG 2.2.
- Conformance level - The degree to which a website complies with WCAG. Level A is must-have, AA is should-have (a common target), and AAA represents maximized accessibility.
- Success Criteria - Each WCAG principle contains sub-categories which themselves contain specific success criteria. This means when you reference a success criterion it will have a number like "2.4.1: Bypass Blocks".
- WAI-ARIA (Web Accessibility Initiative - Accessible Rich Internet Applications) - A specification of semantic requirements for assistive technologies like screen readers.
