Accessibility: A brief 6,000 word introduction

Web accessibility ensures websites are usable by people with disabilities, including visual, auditory, motor, and cognitive impairments. This includes screen reader compatibility, keyboard navigation, sufficient color contrast, captions for videos, alternative text for images, and clear navigation. Approximately 15% of the global population (1 billion people) has some form of disability, making accessibility both an ethical imperative and significant market opportunity.

WCAG (Web Content Accessibility Guidelines) are international standards for web accessibility developed by W3C. Current version is WCAG 2.1 with three levels: A (basic), AA (standard for most compliance), and AAA (enhanced). WCAG 2.1 AA is the legal standard referenced in ADA lawsuits and Section 508 compliance. Guidelines cover: perceivable content, operable interfaces, understandable information, and robust technical implementation.

In the US, web accessibility is legally required for: government websites (Section 508), businesses under ADA Title III (court interpretations vary by circuit), higher education institutions receiving federal funding, and healthcare organizations. While the ADA doesn't explicitly mention websites, courts have increasingly ruled websites are "places of public accommodation." In 2021, 2,895 ADA website lawsuits were filed in federal court, making compliance both a legal protection and risk mitigation strategy.

Building accessibility from the start adds approximately 5-10% to project costs. Retrofitting accessibility into existing sites costs significantly more: $15,000-40,000 for comprehensive audits and remediation of small-to-medium sites, and $50,000-150,000+ for large enterprise sites. However, the average ADA website settlement is $30,000-75,000, making proactive compliance far more cost-effective than legal defense. Ongoing accessibility testing should be 3-5% of maintenance budgets.

The top accessibility violations include: missing alt text on images (67% of homepages), insufficient color contrast (53%), empty links or unclear link text, missing form labels (47%), missing page language declaration, keyboard navigation issues, missing heading structure, and inaccessible PDF documents. These issues prevent screen reader users, keyboard-only users, and users with visual impairments from accessing content. Most violations are preventable through proper HTML and design practices.