Web accessibility means designing and developing websites that can be used by everyone, including people with visual, auditory, motor, or cognitive disabilities. An estimated 15% of the world's population experiences some form of disability.
Using proper HTML elements is the foundation of accessibility. Use
Accessible Rich Internet Applications (ARIA) attributes supplement HTML when native semantics aren't enough. Use role="navigation", role="main", role="complementary". Add aria-label for descriptive context. Use aria-expanded for toggle buttons.
Ensure sufficient color contrast between text and backgrounds. The WCAG AA standard requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. Never convey information through color alone — add icons or text labels.
All interactive elements must be reachable and usable via keyboard. Use tabindex="0" to make non-focusable elements focusable. Ensure visible focus indicators (don't use outline: none without providing an alternative). Test by tabbing through your entire page.
Every image needs alt text. Decorative images: alt="". Informative images: describe what's shown. Functional images (links/buttons): describe the action. Complex images (charts): provide a detailed description nearby.