web-accessibility.md

Web Accessibility

Web Accessibility is the practice that ensures websites, tools, and technologies are designed and developed so that people with disabilities can use them.

It's important for a number of reasons like, the need for equal access to the web for everyone, and many more.

Web accessibility relies on several components that work together:

• Web content: any part of a website
• User agents: software used to access web content
• Authoring tools: software or services used to produce web content

The W3C Web Accessibility Initiative (WAI) develops Web accessibility standards for these different components:

• Web content: Web Content Accessibility Guidelines (WCAG)
• User agents: User Agent Accessibility Guidelines (UAAG)
• Authoring tools: Authoring Tool Accessibility Guidelines (ATAG)

At the top are four principles that provide the foundation for Web accessibility:

1. Perceivable
2. Operable
3. Understandable
4. Robust

Under the principles are guidelines that provide the basic goals that authors should work toward:

1. Perceivable
   • Provide text alternatives for non-text content
   • Provide captions and other alternatives for multimedia
   • Create content that can be presented in different ways without losing meaning
   • Make it easier for users to see and hear content
2. Operable
   • Make all functionality available from a keyboard
   • Provide users enough time to read and use content
   • Do not use content that causes seizures or physical reactions
   • Help users navigate and find content
   • Make it easier to use inputs other than keyboard
3. Understandable
   • Make text readable and understandable
   • Make content appear and operate in predictable ways
   • Help users avoid and correct mistakes
4. Robust
   • Maximize compatibility with current and future user tools

For each guideline, there are testable success criteria, which are at three levels of conformance: A (lowest), AA, and AAA (highest). For more on guidelines and success criterion see Understanding WCAG 2.1.

For each guideline and success criteria there are documented techniques which fall into two categories: those that are sufficient for meeting the success criteria and those that are advisory which go beyond what is required and allow for better addressing of the guidelines. For more on techniques see Techniques for WCAG 2.1.

Links

• Web Content Accessibility Guidelines (WCAG) 2.1
• Accessible Rich Internet Applications (WAI-ARIA) 1.1
• Introduction to Web Accessibility and W3C Standards (4 minute video)
• Web Accessibility Initiative (WAI) @ W3C
• Resources for Developers @ W3C
• How to Meet WCAG 2.1 (Quick Reference)
• Accessibility @ MDN
• The A11y Project