level: AAA
Level AAA is the highest level of compliance, making the most accommodations for the broadest range of people. It’s hard to achieve due to the number of rules and sometimes conflicting requirements. Successfully implement every success criterion under Level AAA, AA, and A to achieve this standard.
1.2.6 Sign Language (Pre-recorded)
All prerecorded videos with audio must include a sign language interpretation.
1.2.7 Extended Audio Description (Pre-recorded)
Prerecorded videos must include extended audio descriptions if important visual content can’t be described during normal playback like important visual details, on-screen text not spoken aloud, or scenes without natural audio breaks.
1.2.8 Media Alternative (Pre-recorded)
Prerecorded videos must have a full text alternative—even if captions and audio descriptions are already available—that includes all speech, relevant sound effects (like music, alarms, or laughter), and important visual content.
1.2.9 Audio-only (Live)
Live audio-only content must include a real-time text alternative, such as; captions, or live transcripts.
1.3.6 Identify Purpose
The purpose of regions and common elements must be defined in the code using semantic HTML or ARIA attributes, so that; assistive technologies can communicate their meaning, and; browsers can adapt or simplify the interface (e.g. hide non-essential content).
1.4.6 Contrast (Enhanced)
Text contrast against its background must be at least 7:1 for normal text, or 4.5:1 for large text (over 24px, or bold and over 19px).
1.4.7 Low or No Background Audio
For prerecorded audio with speech, any background sound must be at least 20dB lower than the speech, or there must be a way to turn it off.
1.4.8 Visual Presentation
Blocks of text (like paragraphs) must have a line height of at least 1.5, not be justified, and stay within 80 characters (or 40 for CJK scripts). Allow users to adjust spacing and colors using custom styles.
1.4.9 Images of Text (No Exception)
Text must be actual text, not images of text (no exception, not even for design or aesthetic reasons).
2.1.3 Keyboard (No Exception)
All functionality must be operable using a keyboard alone (no exception, not even for tasks involving gestures like drag-and-drop or pointer-based interaction).
