WCAG 2.1 AA Rules

Rule Label Description
1.1.1 non-text-content All non-text content (e.g. images) has a text alternative that serves the equivalent purpose.
1.2.1 audio-video-only-prerecorded Prerecorded audio-only and video-only content has an alternative that presents equivalent information.
1.2.2 captions-prerecorded Captions are provided for all prerecorded audio content in synchronized media.
1.2.3 audio-description-or-media-alternative-prerecorded An audio description or a full text alternative is provided for prerecorded video content.
1.2.4 captions-live Captions are provided for all live audio content in synchronized media.
1.2.5 audio-description-prerecorded Audio description is provided for all prerecorded video content in synchronized media.
1.3.1 info-and-relationships Information, structure, and relationships conveyed through presentation are also available in markup (e.g. real headings, lists, and table headers).
1.3.2 meaningful-sequence Content is presented in a reading order that can be programmatically determined and matches the visual order.
1.3.3 sensory-characteristics Instructions do not rely solely on shape, size, visual location, orientation, or sound to identify content.
1.3.4 orientation Content does not restrict its view to a single display orientation unless a specific orientation is essential.
1.3.5 identify-input-purpose The purpose of input fields collecting user information can be programmatically determined, e.g. via the autocomplete attribute.
1.4.1 use-of-color Color is not used as the only visual means of conveying information, indicating an action, or distinguishing an element.
1.4.2 audio-control If audio plays automatically for more than 3 seconds, a mechanism is available to pause, stop, or control its volume independently of overall system volume.
1.4.3 contrast-minimum Text and images of text have a contrast ratio of at least 4.5:1 against their background (3:1 for large text).
1.4.4 resize-text Text can be resized up to 200% without loss of content or functionality, without requiring assistive technology.
1.4.5 images-of-text Text is used rather than images of text to convey information, except where a particular presentation is essential.
1.4.10 reflow Content can be presented without loss of information or functionality without requiring scrolling in two dimensions at standard zoom and viewport widths.
1.4.11 non-text-contrast User interface components and graphical objects have a contrast ratio of at least 3:1 against adjacent colors.
1.4.12 text-spacing No loss of content or functionality occurs when users override line height, paragraph spacing, letter spacing, and word spacing.
1.4.13 content-on-hover-or-focus Additional content revealed on hover or focus (e.g. tooltips) is dismissible, hoverable, and remains visible until dismissed.
2.1.1 keyboard All functionality is operable through a keyboard interface without requiring specific timings for individual keystrokes.
2.1.2 no-keyboard-trap Keyboard focus is never trapped in a component; focus can always be moved away using only the keyboard.
2.1.4 character-key-shortcuts Single-character key shortcuts can be turned off, remapped, or are only active on focus, so they do not conflict with assistive technology.
2.2.1 timing-adjustable For any time limit set by content, users can turn off, adjust, or extend the limit before it expires.
2.2.2 pause-stop-hide Moving, blinking, scrolling, or auto-updating content can be paused, stopped, or hidden by the user.
2.3.1 three-flashes-or-below-threshold Content does not flash more than three times per second, or the flash is below the general flash and red flash thresholds.
2.4.1 bypass-blocks A mechanism is available to bypass blocks of repeated content, such as a "skip to main content" link.
2.4.2 page-titled Pages have titles that describe their topic or purpose.
2.4.3 focus-order Focusable elements receive focus in an order that preserves meaning and operability.
2.4.4 link-purpose-in-context The purpose of each link can be determined from the link text alone or together with its programmatically determined context.
2.4.5 multiple-ways More than one way is available to locate a page within a set of pages, such as a search function and a navigation menu.
2.4.6 headings-and-labels Headings and labels describe the topic or purpose of the content or control they introduce.
2.4.7 focus-visible The keyboard focus indicator is visible when a UI component receives keyboard focus.
2.5.1 pointer-gestures Functionality operable with a multipoint or path-based gesture can also be operated with a single pointer without a path-based gesture.
2.5.2 pointer-cancellation Functions triggered by a single pointer can be cancelled, e.g. by aborting before completion or triggering on the up-event rather than the down-event.
2.5.3 label-in-name The accessible name of a control that includes visible text includes that visible text.
2.5.4 motion-actuation Functionality operable by device motion (e.g. shaking or tilting) can also be operated by conventional UI controls, and motion actuation can be disabled.
3.1.1 language-of-page The default human language of each page can be programmatically determined via the html lang attribute.
3.1.2 language-of-parts The human language of each passage or phrase can be programmatically determined when it differs from the page's default language.
3.2.1 on-focus Receiving focus on a component does not trigger a change of context, such as an automatic form submission or new window.
3.2.2 on-input Changing the value of a form control does not automatically trigger a change of context unless the user is advised beforehand.
3.2.3 consistent-navigation Navigational mechanisms that are repeated on multiple pages occur in the same relative order each time they appear.
3.2.4 consistent-identification Components with the same functionality across pages are identified consistently, e.g. using the same icon or label.
3.3.1 error-identification When an input error is automatically detected, the item in error is identified and the error is described to the user in text.
3.3.2 labels-or-instructions Labels or instructions are provided when content requires user input.
3.3.3 error-suggestion When an input error is detected and suggestions for correction are known, those suggestions are provided to the user.
3.3.4 error-prevention-legal-financial-data For pages that cause legal or financial commitments, submissions are reversible, checked for errors, or confirmed before finalizing.
4.1.1 parsing Markup has complete start/end tags, is nested correctly, and elements do not contain duplicate attributes or IDs.
4.1.2 name-role-value For all UI components, the name and role can be programmatically determined, and states/values can be set by the user and are exposed to assistive technology.
4.1.3 status-messages Status messages can be programmatically determined through role or properties (e.g. aria-live) without requiring focus.