WCAG 2.1 AAA Standards

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Conformance Levels

High-level Web Accessibility

Triple-A conformance usually requires a website to have been built with accessibility in mind from the very beginning. With additional technical considerations such as reading level, definitions of technical terms, robust accessibility tools embedded into the site itself, triple-a conformance has more stringent guidelines than those present in single-a and double-a. Seen on many state and public-service sites, triple-a usually requires significant resources to fully meet the guidelines.

Triple-A Overview


  • Sign language interpretation and robust audio descriptions are made available for streaming media.
  • A media alternative is made available for prerecorded media, and an audio-only alternative is made available for live media.
  • There includes minimal or no background audio on the website.


  • Text and images of text have a 7:1 minimum contrast ratio.
  • There exist no images with text.
  • Hyperlinks self-identify the ultimate destination.
  • Section headings are present to break up content.


  • Every action on the site can be performed with only a keyboard.
  • Additional web accessibility tools need to be available on the site, such as a color switcher and text resizer.
  • A definition exists for identifying the meaning of unusual words, idioms, abbreviations, pronunciation, or technical terms.
  • The website must request user input to change.
  • There exist context-sensitive “help” features, and there should exist a mechanism to prevent erroneous input.


  • There are no time limits imposed on the user, except for non-interactive elements, and no interruptions can occur during regular browsing, such as user re-authentication.  
  • There are no flashing blocks of content.
  • The reading level of text on any page must be no more advanced than grade 9-10.

Success Criterion