What is an Accessibility?

Understanding Accessibility

Accessibility means designing digital experiences so people with different abilities can use them. A person may browse with a keyboard, screen reader, voice control, magnification software, captions, or switch device. Good accessibility covers the interface, written content, images, forms, videos, documents, and technical code.

Related glossary terms: Web Content Accessibility Guidelines, User Experience, User Interface.

Disability can affect vision, hearing, movement, speech, memory, attention, or learning. Limitations can also be temporary, such as a broken arm, or situational, such as bright sunlight or a noisy room. Accessible design reduces barriers through features like alternative text, visible focus indicators, clear headings, sufficient colour contrast, captions, and plain instructions.

How Accessibility Works, Is Measured, or Is Used?

Web teams often use the Web Content Accessibility Guidelines, known as WCAG, as a practical reference. WCAG organizes requirements around four principles. Content must be perceivable, operable, understandable, and compatible with current and future user agents. The guidelines define testable success criteria at Levels A, AA, and AAA, with Level AA commonly selected for general website projects.

An accessibility workflow starts with requirements and continues through design, development, testing, release, and maintenance. Automated tools can detect missing image text, some contrast failures, invalid markup, and certain form problems. They can't reliably judge whether alternative text conveys the right meaning. They also can't confirm whether a complete task works for a screen-reader user. So manual checks remain essential.

Evaluation should combine code inspection, keyboard testing, screen-reader testing, zoom checks, colour review, and testing with people who have disabilities when possible. A useful test follows real tasks, such as finding a product, completing a form, changing an account setting, or reading a service page. Teams should record the issue, affected users, severity, location, expected behaviour, and repair status.

Why Accessibility Matters?

Accessibility affects whether people can find information, complete transactions, submit applications, or contact an organisation. A missing label can prevent form completion. While poor contrast can make text hard to read. Captions support people who are deaf or hard of hearing, and they also help anyone watching video without sound.

Accessibility also improves code quality and task clarity. Semantic HTML gives browsers and assistive technology useful structure, while descriptive links and predictable navigation reduce user effort. Legal duties differ by country, sector, and service type. A WCAG review doesn't replace advice about applicable law or procurement requirements.

When Accessibility Matters Most?

Accessibility deserves attention before visual design and content production begin. Late changes can affect layouts, components, media, and testing plans. It matters especially for public services, education, healthcare, finance, employment, ecommerce, and any service that requires forms or identity checks. A barrier in one critical step can prevent access to the entire service.

Review accessibility during redesigns, platform migrations, new feature releases, and content updates. Give extra attention to forms, navigation, multimediaand error messages. A practical release check asks whether a keyboard user can reach every control. It asks whether focus remains visible and whether screen readers receive meaningful names. It also checks whether users can recover from mistakes.