Perceivable
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WCAG 1.1.1: Non-text Content
WCAG 1.1.1 requires that all non-text content — images, icons, controls, and media — has a text alternative that conveys the same purpose or information, enabling users who cannot perceive visual content to access it through assistive technologies such as screen readers.
WCAG 1.2.1: Audio-only and Video-only (Prerecorded)
WCAG 1.2.1 requires that prerecorded audio-only and video-only content have a text-based or media alternative so users who cannot hear or see the media can still access the information. This is a Level A requirement, meaning it is the minimum baseline for web accessibility compliance.
WCAG 1.2.2: Captions (Prerecorded)
WCAG 1.2.2 requires that all prerecorded audio content in synchronized media (video with audio) includes accurate captions. This ensures deaf and hard-of-hearing users can access spoken dialogue, sound effects, and other meaningful audio information.
WCAG 1.2.3: Audio Description or Media Alternative (Prerecorded)
WCAG 1.2.3 requires that prerecorded synchronized media (video with audio) provides either an audio description of the visual content or a full text alternative, ensuring users who are blind or have low vision can access information conveyed visually.
WCAG 1.3.1: Info and Relationships
WCAG 1.3.1 requires that information, structure, and relationships conveyed through visual presentation can also be determined programmatically or are available in text, ensuring that users of assistive technologies receive the same structural context as sighted users.
WCAG 1.3.2: Meaningful Sequence
WCAG 1.3.2 requires that when the order of content affects its meaning, that sequence must be determinable programmatically so assistive technologies can present it correctly. Failing this criterion causes screen reader users and other AT users to receive content in a confusing or meaningless order.
WCAG 1.3.3: Sensory Characteristics
WCAG 1.3.3 requires that instructions for using content do not rely solely on sensory characteristics such as shape, color, size, visual location, orientation, or sound. This ensures that users who cannot perceive those sensory cues — due to blindness, color blindness, deafness, or other disabilities — can still understand and operate all features.
WCAG 1.4.1: Use of Color
WCAG 1.4.1 requires that color is never the sole means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. This criterion ensures users who cannot perceive color differences—including people with color blindness or low vision—can still access all content and functionality.
WCAG 1.4.2: Audio Control
WCAG 1.4.2 requires that any audio playing automatically for more than three seconds must offer users a mechanism to pause, stop, or control its volume independently of the system volume. This prevents audio from interfering with screen reader output and protects users from unexpected, disorienting sound.
WCAG 1.3.4: Orientation
WCAG 1.3.4 Orientation requires that content does not restrict its view and operation to a single display orientation, such as portrait or landscape, unless a specific orientation is essential. This criterion ensures users who cannot physically rotate their devices—such as those with mounted tablets or motor impairments—can still access all content.
WCAG 1.3.5: Identify Input Purpose
WCAG 1.3.5 requires that the purpose of each input field collecting personal information can be programmatically determined, enabling browsers and assistive technologies to autofill, label, or adapt fields automatically. This is essential for users with cognitive disabilities and motor impairments who benefit from reduced manual input.
WCAG 1.4.3: Contrast (Minimum)
WCAG 1.4.3 requires that text and images of text have a contrast ratio of at least 4.5:1 against their background (3:1 for large text), ensuring that users with low vision or color deficiencies can read content without assistive technology.
WCAG 1.4.4: Resize Text
WCAG 1.4.4 requires that text can be resized up to 200% without assistive technology and without loss of content or functionality. This criterion is essential for users with low vision who rely on browser zoom or custom font-size settings to read web content comfortably.
WCAG 1.4.5: Images of Text
WCAG 1.4.5 requires that text conveying information be presented as actual text rather than as an image of text, except where a specific visual presentation is essential or the image can be visually customized by the user. This criterion is critical for users who need to resize, recolor, or reflow text to read it comfortably.
WCAG 1.4.10: Reflow
WCAG 1.4.10 Reflow requires that content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions, when displayed at a width equivalent to 320 CSS pixels. This ensures users who rely on zoom or small viewports — including people with low vision and mobile users — can access all content without horizontal scrolling.
WCAG 1.4.11: Non-text Contrast
WCAG 1.4.11 requires that user interface components and graphical objects have a contrast ratio of at least 3:1 against adjacent colors, ensuring that people with low vision can perceive interactive controls, focus indicators, and meaningful graphics without assistive technology.
WCAG 1.4.12: Text Spacing
WCAG 1.4.12 requires that no loss of content or functionality occurs when users override text spacing properties — line height, letter spacing, word spacing, and spacing after paragraphs — to specific minimum values. This criterion is essential for users with dyslexia, low vision, and cognitive disabilities who rely on custom spacing to read effectively.
WCAG 1.4.13: Content on Hover or Focus
WCAG 1.4.13 requires that additional content appearing on pointer hover or keyboard focus is dismissible, hoverable, and persistent — ensuring users with low vision, motor impairments, and cognitive disabilities can access and interact with tooltip-style content without losing it unexpectedly.
WCAG 1.2.6: Sign Language (Prerecorded)
WCAG 1.2.6 requires that sign language interpretation be provided for all prerecorded audio content in synchronized media. This criterion ensures that Deaf users whose primary language is a sign language can fully access audio information that may not be adequately conveyed through captions alone.
WCAG 1.2.7: Extended Audio Description (Prerecorded)
WCAG 1.2.7 requires that when pauses in foreground audio are insufficient to convey all visual information, extended audio descriptions—achieved by pausing the video—must be provided for prerecorded synchronized media. This ensures blind and low-vision users can fully understand complex visual content that standard audio descriptions cannot cover.
WCAG 1.2.8: Media Alternative (Prerecorded)
WCAG 1.2.8 requires that a full text alternative is provided for all prerecorded synchronized media (audio-video) and prerecorded video-only content, ensuring that users who cannot perceive audio or visual information can access the complete content through text.
WCAG 1.2.9: Audio-only (Live)
WCAG 1.2.9 requires that all live audio-only content — such as live radio broadcasts or audio-only streams — be accompanied by a real-time text alternative equivalent, such as a live captions feed or text transcript updated synchronously. This ensures that users who are deaf or hard of hearing can access live audio content without relying on the audio track itself.
WCAG 1.4.6: Contrast (Enhanced)
WCAG 1.4.6 requires a minimum contrast ratio of 7:1 for normal text and 4.5:1 for large text between foreground and background colors, going beyond the AA threshold to ensure readability for users with low vision, color deficiencies, or those operating in challenging lighting conditions.
WCAG 1.4.7: Low or No Background Audio
WCAG 1.4.7 requires that pre-recorded audio content containing speech either has no background sounds, allows background sounds to be turned off, or keeps background sounds at least 20 dB quieter than the foreground speech. This protects users with hearing loss and cognitive disabilities who struggle to separate speech from competing audio.
WCAG 1.4.8: Visual Presentation
WCAG 1.4.8 requires that blocks of text be visually presented in ways users can control — covering foreground and background colors, line width, line spacing, and text alignment — so that people with reading, cognitive, or low-vision disabilities can comfortably read content without loss of information.
WCAG 1.4.9: Images of Text (No Exception)
WCAG 1.4.9 requires that text be presented using actual text rather than images of text, with no exceptions beyond purely decorative content or cases where the specific visual presentation is essential to the information conveyed. This criterion ensures all users can adjust text rendering to suit their individual needs.