Glossary

What Is Web Accessibility (WCAG)?

Web accessibility (often abbreviated a11y) is the practice of designing and building websites that can be used by everyone — including people with visual, auditory, motor, or cognitive disabilities. The Web Content Accessibility Guidelines (WCAG), maintained by the W3C, provide the international standard for web accessibility. WCAG 2.1 AA is the most widely required compliance level for public-facing websites.

The four WCAG principles (POUR)

Perceivable — all information must be presentable in ways users can perceive (alt text on images, captions on videos, sufficient colour contrast). Operable — all interface components must be operable (keyboard navigation, no seizure-inducing content, enough time to interact). Understandable — content and UI must be understandable (clear language, consistent navigation, helpful error messages). Robust — content must be interpreted reliably by assistive technologies (valid HTML, ARIA attributes used correctly).

Key accessibility requirements

Colour contrast: normal text must meet 4.5:1 contrast ratio (AA level). Large text (18pt+ or 14pt bold) needs 3:1. Alt text: all images need descriptive alt attributes. Keyboard navigation: all interactive elements must be reachable and operable by keyboard. Focus indicators: focused elements must be visually distinct. Heading hierarchy: single H1, logical H2–H6 structure. Form labels: every input must have an associated label element.

Accessibility and SEO

Many accessibility practices directly benefit SEO: alt text helps Google understand images (and is used for image search ranking), semantic HTML helps crawlers parse page structure, fast performance benefits users with slow connections, and clear heading hierarchy helps both users and crawlers understand content organisation. Accessible sites typically rank better.

Web Accessibility (WCAG) & Canvas Builder

Canvas Builder generates HTML using Bootstrap 5, which includes built-in accessibility features — ARIA attributes on modals, dropdowns, and navigation, plus proper semantic structure for screen reader compatibility.

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Frequently Asked Questions

What WCAG level should I target?

WCAG 2.1 AA is the practical standard for most websites and the level required by many accessibility laws (ADA in the US, EN 301 549 in Europe, AODA in Canada). AAA is the highest level and is impractical for most general sites.

Does Canvas Builder generate accessible HTML?

Canvas Builder generates HTML with proper alt attributes on images, semantic structural elements, and Bootstrap 5's built-in accessibility features including ARIA roles on interactive components.