Web Accessibility
Designing websites and applications usable by people with disabilities.
Definition
Web accessibility is the practice of designing and developing websites and applications that can be used by everyone, including people with disabilities. This encompasses visual impairments (blindness, low vision, color blindness), auditory impairments (deafness, hearing loss), motor impairments (limited fine motor control, tremors), cognitive impairments (learning disabilities, attention disorders), and temporary or situational disabilities.
Accessibility implementation follows established standards, primarily the Web Content Accessibility Guidelines (WCAG) published by the W3C. WCAG is organized around four principles: Perceivable (information must be presentable in ways users can perceive), Operable (interface components must be operable by all users), Understandable (information and operation must be understandable), and Robust (content must be robust enough to work with assistive technologies).
Practical accessibility implementation includes providing alternative text for images, ensuring sufficient color contrast, supporting keyboard navigation, creating logical heading structures, providing captions and transcripts for media, designing forms with proper labels and error handling, avoiding content that could trigger seizures, and testing with screen readers and other assistive technologies.
Accessibility standards have conformance levels (A, AA, AAA) representing increasing stringency. Level AA is typically required for legal compliance and is achievable for most websites with appropriate design and development practices.
Why It Matters
Accessibility ensures that websites and applications serve everyone rather than excluding the substantial population with disabilities. Approximately 15-20% of people have some form of disability, and many more experience situational or temporary impairments. Excluding these users excludes significant portions of potential audiences.
Legal requirements increasingly mandate accessibility. Laws like the Americans with Disabilities Act (ADA), Section 508 for government contractors, and European accessibility regulations require or encourage accessible digital experiences. Non-compliance exposes organizations to legal liability, and accessibility lawsuits have increased dramatically.
Accessibility improvements often benefit all users. Captions help users in noisy or quiet environments. Good color contrast improves readability for everyone. Logical navigation structures help all users find content. Accessibility optimizations frequently improve general usability.
SEO and accessibility overlap significantly. Screen readers and search engines consume content similarly—both need clear structure, alternative text, meaningful headings, and well-organized content. Accessible sites often rank better as a side effect of their structural quality.
Examples in Practice
An e-commerce site audits accessibility and discovers their checkout process is unusable with screen readers. They implement proper form labels, error announcements, and focus management. The fixes enable visually impaired customers to complete purchases independently.
A video platform implements captions and transcripts for all content, benefiting deaf users while also improving SEO (search engines can index the text) and serving users who prefer reading or are in sound-off environments.
A banking application ensures all functionality works via keyboard, enabling customers with motor impairments who cannot use mice. The keyboard-accessible interface also benefits power users who prefer keyboard navigation.
A media company receives an accessibility complaint and conducts a comprehensive audit revealing issues with color contrast, missing alt text, and inaccessible interactive elements. The remediation project addresses these issues, achieving WCAG AA conformance and reducing legal exposure.