A set of recommendations for improving web accessibility, primarily for people with disabilities but also for all user agents, including highly limited devices, such as mobile phones. The Web Content Accessibility Guidelines (WCAG) are part of a series published by the Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C), the main international standards organization for the Internet. WCAG 2.0 was published in December 2008 and became an ISO standard, ISO/IEC 40500:2012 in October 2012. WCAG 2.2 became a W3C Recommendation on 5 October 2023.
WCAG Levels of Conformance
WCAG guidelines are organized into three levels of conformance, each with progressively stricter criteria:
- Level A: The most basic level of accessibility and represents the minimum requirements for making a website usable by individuals with disabilities. Compliance with Level A guidelines ensures that the most significant barriers are addressed, but it may not be sufficient for providing a fully accessible user experience.
- Level AA: This level builds upon Level A, adding more stringent requirements to address a broader range of accessibility issues. Level AA conformance is considered the industry standard for most websites, as it strikes a balance between accessibility and implementation complexity. Compliance with Level AA guidelines typically results in a website that is more accessible to a wider range of users with disabilities.
- Level AAA: The highest level of accessibility and includes the most comprehensive set of criteria. Achieving Level AAA conformance is challenging and may not be feasible for all websites, as it can require significant changes to design and functionality. Level AAA guidelines are aimed at providing the most accessible user experience possible, but meeting all of these criteria is not always necessary or practical for every website. It is essential to consider the target audience and the nature of a website when determining which WCAG level to strive for.
WCAG Principles and Guidelines
Here is a breakdown of some of the key requirements from the WCAG, grouped by their principles:
- Perceivable: Ensure content is presented in ways that users can perceive. This includes providing text alternatives for non-text content, offering captions, transcripts, and audio descriptions for multimedia content, and creating content that can be presented in different ways without losing its meaning.
- Operable: Make all functionality accessible through a keyboard, provide users with sufficient time to read and interact with the content, and design content without elements that might cause seizures or other physical reactions.
- Understandable: Use clear, concise language and provide explanations for complex content, maintain consistent design and functionality throughout the website, and offer guidance and error prevention mechanisms.
- Robust: Develop content that is compatible with a wide range of user agents, devices, and assistive technologies, using well-structured and valid code. Keep up-to-date with evolving technologies and best practices to ensure that the website remains accessible as technology advances.
Meeting the appropriate WCAG level will help ensure a website is accessible to users with disabilities and complies with relevant regulations, such as the ADA.
