Web Accessibility (a11y)
Designing websites usable by everyone, including people with disabilities.
Web accessibility means a site can be used by people with disabilities — those using a screen reader, navigating by keyboard, or needing higher contrast. It is measured against WCAG, which sets testable criteria for contrast, labels, focus order and structure. Most accessibility failures are also usability failures, which is why they tend to correlate with worse engagement.
Definition
Web accessibility (often abbreviated a11y) means designing websites that can be used by everyone, including people with disabilities — visual, auditory, motor, and cognitive. WCAG (Web Content Accessibility Guidelines) defines the standards at three levels: A, AA, and AAA.
Key accessibility requirements: proper heading hierarchy, alt text on images, keyboard navigation, sufficient color contrast, ARIA labels, and semantic HTML.
Why It Matters
15% of the world's population lives with some form of disability. Beyond the ethical imperative, accessibility is legally required in many jurisdictions (ADA, EAA). Google also considers accessibility as a quality signal — good a11y correlates with good SEO.
Example
A button labeled only with an icon (no text, no aria-label) is invisible to screen readers. Fix: add aria-label="Search" or include visible text. SlapMyWeb's self-audit scored 100/100 on accessibility.
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