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Success CriterionVersionLevelImpacted PopulationsExplanation
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1.1.1 Non-text Content2.0AScreen reader users (blind, low vision, and neurodivergent people); People with dexterity impairment using voice controlImages, form image buttons, and image map hot spots have appropriate, equivalent alternative text.
Images that do not convey content, are decorative, or contain content that is already conveyed in text are given empty alternative text (alt="") or implemented as CSS backgrounds. All linked images have descriptive alternative text.
Equivalent alternatives to complex images are provided in context or on a separate linked page.
Form buttons have a descriptive value.
Form inputs have associated text labels.
Embedded multimedia is identified via accessible text.
Frames and iframes are appropriately titled.
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1.2.1 Prerecorded Audio-only and Video-only2.0ADeaf and hard of hearing people; Language learnersA transcript of relevant content is provided for non-live audio-only (audio podcasts, MP3 files, etc.).
A transcript or audio description of relevant content is provided for non-live video-only, unless the video is decorative.
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1.2.2 Captions (Prerecorded)
2.0ADeaf and hard of hearing people; Language learnersSynchronized captions are provided for non-live video (YouTube videos, etc.).
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1.2.3 Audio Description or Media Alternative (Prerecorded)
2.0ADeaf and hard of hearing people; Language learnersA transcript or audio description is provided for non-live video.
NOTE: Only required if there is relevant visual content that is not presented in the audio.
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1.2.4 Captions (Live)
2.0AADeaf and hard of hearing people; Language learnersSynchronized captions are provided for live media that contains audio (audio-only broadcasts, web casts, video conferences, etc.)
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1.2.5 Audio Description (Prerecorded)
2.0AABlind and low vision peopleAudio descriptions are provided for non-live video.
NOTE: Only required if there is relevant visual content that is not presented in the audio.
While not required at Level AA, for optimal accessibility we recommend transcripts in addition to audio descriptions.
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1.3.1 Info and Relationships
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with dexterity impairment using voice control; People who rely on keyboard control; People with cognitive differences who view interfaces using an adapted layoutSemantic markup is used to designate headings (<h1>), regions/landmarks, lists (<ul>, <ol>, and <dl>), emphasized or special text (<strong>, <code>, <abbr>, <blockquote>, for example), etc. Semantic markup is used appropriately.
Tables are used for tabular data and data cells are associated with their headers. Data table captions, if present, are associated to data tables.
Text labels are associated with form input elements. Related form elements are grouped with fieldset/legend. ARIA labelling may be used when standard HTML is insufficient.
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1.3.2 Meaningful Sequence
2.0AScreen reader users (blind, low vision, and neurodivergent people); People who rely on keyboard control; People with cognitive differences who view interfaces using an adapted layoutThe reading and navigation order (determined by code order) is logical and intuitive.
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1.3.3 Sensory Characteristics
2.0ABlind and low vision people; Deaf and hard of hearing peopleInstructions do not rely upon shape, size, or visual location (e.g., "Click the square icon to continue" or "Instructions are in the right-hand column").
Instructions do not rely upon sound (e.g., "A beeping sound indicates you may continue.").
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1.3.4 Orientation
2.1AAAll peopleOrientation of web content is not restricted to only portrait or landscape, unless a specific orientation is necessary.
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1.3.5 Identify Input Purpose
2.1AAPeople with memory, language, or cognitive disibilities; People with dexterity or mobility impairmentsInput fields that collect certain types of user information have an appropriate autocomplete attribute defined.
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1.4.1 Use of Color
2.0ABlind and low vision people; People who have color blindnessColor is not used as the sole method of conveying content or distinguishing visual elements.
Color alone is not used to distinguish links from surrounding text unless the contrast ratio between the link and the surrounding text is at least 3:1 and an additional distinction (e.g., it becomes underlined) is provided when the link is hovered over and receives focus.
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1.4.2 Audio Control
2.0ABlind and low vision people; Deaf and hard of hearing people; People with ADD or difficulty focusing on content when audio is playingA mechanism is provided to stop, pause, mute, or adjust volume for audio that automatically plays on a page for more than 3 seconds.
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1.4.3 Contrast (Minimum)
2.0AAPeople with low vision; People on mobile devices in a sunny environmentText and images of text have a contrast ratio of at least 4.5:1.
Large text - at least 18 point (typically 24px) or 14 point (typically 18.66px) and bold - has a contrast ratio of at least 3:1.
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1.4.4 Resize text
2.0AAPeople with low visionThe page is readable and functional when the page is zoomed to 200%. NOTE: 1.4.10 (below) introduces a much higher requirement for zoomed content.
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1.4.5 Images of Text
2.0AABlind and low vision peopleIf the same visual presentation can be made using text alone, an image is not used to present that text.
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1.4.10 Reflow
2.1AAPeople with low vision; People on mobile devicesNo loss of content or functionality occurs and horizontal scrolling is avoided when content is presented at a width of 320 pixels.This requires responsive design for most web sites. This is best tested by setting the browser window to 1280 pixels wide and then zooming the page content to 400%.

Content that requires horizontal scrolling, such as data tables, complex images (such as maps and charts), toolbars, etc. are exempted.
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1.4.11 Non-text Contrast
2.1AAPeople with low visionA contrast ratio of at least 3:1 is present for differentiating graphical objects (such as icons and components of charts or graphs) and author-customized interface components (such as buttons, form controls, and focus indicators/outlines).
At least 3:1 contrast must be provided in the various states (focus, hover, active, etc.) of author-customized interactive components.
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1.4.12 Text Spacing
2.1AAPeople with low vision; People with cognitive or reading disabilities like dyslexiaNo loss of content or functionality occurs when the user adapts paragraph spacing to 2 times the font size, text line height/spacing to 1.5 times the font size, word spacing to .16 times the font size, and letter spacing to .12 times the font size.
This is best supported by avoiding pixel height definitions for elements that contain text.
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1.4.13 Content on Hover or Focus
2.1AABlind and low vision people; People with cognitive disibilities; People with dexterity impairmentsWhen additional content is presented on hover or keyboard focus:The newly revealed content can be dismissed (generally via the Esc key) without moving the pointer or keyboard focus, unless the content presents an input error or does not obscure or interfere with other page content.
The pointer can be moved to the new content without the content disappearing.
The new content must remain visible until the pointer or keyboard focus is moved away from the triggering control, the new content is dismissed, or the new content is no longer relevant.
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2.1.1 Keyboard
2.0ABlind and low vision people; People with dexterity and mobility impairments; People who rely on keyboard controlAll page functionality is available using the keyboard, unless the functionality cannot be accomplished in any known way using a keyboard (e.g., free hand drawing).
Page-specified shortcut keys and accesskeys (accesskey should typically be avoided) do not conflict with existing browser and screen reader shortcuts.
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2.1.2 No Keyboard Trap
2.0ABlind and low vision people; People with dexterity and mobility impairments; People who rely on keyboard controlKeyboard focus is never locked or trapped at one particular page element. The user can navigate to and from all navigable page elements using only a keyboard.
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2.1.4 Character Key Shortcuts
2.1AScreen reader users (blind, low vision, and neurodivergent people)If a keyboard shortcut uses printable character keys, then the user must be able to disable the key command, change the defined key to a non-printable key (Ctrl, Alt, etc.), or only activate the shortcut when an associated interface component or button is focused.
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2.2.1 Timing Adjustable
2.0APeople who need more time to react; Screen reader users (blind, low vision, and neurodivergent people); People with dexterity and mobility impairmentsIf a page or application has a time limit, the user is given options to turn off, adjust, or extend that time limit. This is not a requirement for real-time events (e.g., an auction), where the time limit is absolutely required, or if the time limit is longer than 20 hours.
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2.2.2 Pause, Stop, Hide
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disibilities; People with ADD or difficulty focusing on content when a video is playing or animations are presentAutomatically moving, blinking, or scrolling content (such as carousels, marquees, or animations) that lasts longer than 5 seconds can be paused, stopped, or hidden by the user.
Automatically updating content (e.g., a dynamically-updating news ticker, chat messages, etc.) can be paused, stopped, or hidden by the user or the user can manually control the timing of the updates.
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2.3.1 Three Flashes or Below Threshold
2.0APeople with photosensitive epilepsy and other photosensitive seizure disordersNo page content flashes more than 3 times per second unless that flashing content is sufficiently small and the flashes are of low contrast and do not contain too much red. (See general flash and red flash thresholds)
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2.4.1 Bypass Blocks
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with dexterity and mobility impairmentsA link is provided to skip navigation and other page elements that are repeated across web pages.
A proper heading structure and/or identification of page regions/landmarks may be considered a sufficient technique. Because navigating by headings or regions is not supported in most browsers, we recommend a "skip" link (in addition to headings and regions) to best support sighted keyboard users.
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2.4.2 Page Titled
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with severe mobility impairments relying on audio to navigate the web; People with cognitive disabilities, limited short-term memory, and reading disabilitiesThe web page has a descriptive and informative page title.
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2.4.3 Focus Order
2.0APeople with low-vision; People with dexterity and mobility impairments; People who rely on keyboard controlThe navigation order of links, form elements, etc. is logical and intuitive.
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2.4.4 Link Purpose (In Context)
2.0AScreen reader users (blind, low vision, and neurodivergent people); All people, including those who do not identify as disabledThe purpose of each link (or form image button or image map hotspot) can be determined from the link text alone, or from the link text and its context (e.g., surrounding text, list item, previous heading, or table headers).
Links (or form image buttons) with the same text that go to different locations are readily distinguishable.
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2.4.5 Multiple Ways
2.0AAScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disabilities; All people, including those who do not identify as disabledMultiple ways are available to find other web pages on the site - at least two of: a list of related pages, table of contents, site map, site search, or list of all available web pages.
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2.4.6 Headings and Labels
2.0AAScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disabilities, limited short-term memory, and reading disabilities; All people, including those who do not identify as disabledPage headings and labels for form and interactive controls are informative. Avoid duplicating heading (e.g., "More Details") or label text (e.g., "First Name") unless the structure provides adequate differentiation between them.
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2.4.7 Focus Visible
2.0AAPeople with low vision; People with dexterity and mobility impairments; People who rely on keyboard controlIt is visually apparent which page element has the current keyboard focus (i.e., as you tab through the page, you can see where you are).
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2.5.1 Pointer Gestures
2.1AScreen reader users (blind, low vision, and neurodivergent people); People with dexterity and mobility impairments; People who rely on keyboard controlIf multipoint or path-based gestures (such as pinching, swiping, or dragging across the screen) are not essential to the functionality, then the functionality can also be performed with a single point activation (such as activating a button).
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2.5.2 Pointer Cancellation
2.1AScreen reader users (blind, low vision, and neurodivergent people); People with dexterity and mobility impairments; People who rely on keyboard control; All people, including those who do not identify as disabledTo help avoid inadvertent activation of controls, avoid non-essential down-event (e.g., onmousedown) activation when clicking, tapping, or long pressing the screen. Use onclick, onmouseup, or similar instead. If onmouseup (or similar) is used, you must provide a mechanism to abort or undo the action performed.
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2.5.3 Label in Name
2.1APeople with dexterity impairment using voice controlIf an interface component (link, button, etc.) presents text (or images of text), the accessible name (label, alternative text, aria-label, etc.) for that component must include the visible text.
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2.5.4 Motion Actuation
2.1APeople with dexterity and mobility impairmentsFunctionality that is triggered by moving the device (such as shaking or panning a mobile device) or by user movement (such as waving to a camera) can be disabled and equivalent functionality is provided via standard controls like buttons.
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3.1.1 Language of Page
2.0AScreen reader users (blind, low vision, and neurodivergent people); Language learnersThe language of the page is identified using the HTML lang attribute (e.g., <html lang="en">).
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3.1.2 Language of Parts
2.0AAScreen reader users (blind, low vision, and neurodivergent people); Language learnersThe language of page content that is in a different language is identified using the lang attribute (e.g., <blockquote lang="es">).
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3.2.1 On Focus
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with dexterity and mobility impairments; People who rely on keyboard controlWhen a page element receives focus, it does not result in a substantial change to the page, the spawning of a pop-up window, an additional change of keyboard focus, or any other change that could confuse or disorient the user.
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3.2.2 On Input
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with dexterity and mobility impairments; People who rely on keyboard control; People with cognitive disabilities and reading disabilitiesWhen a user inputs information or interacts with a control, it does not result in a substantial change to the page, the spawning of a pop-up window, an additional change of keyboard focus, or any other change that could confuse or disorient the user unless the user is informed of the change ahead of time.
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3.2.3 Consistent Navigation
2.0AAScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disabilities and reading disabilities; All people, including those who do not identify as disabledNavigation links that are repeated on web pages do not change order when navigating through the site.
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3.2.4 Consistent Identification
2.0AAScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disabilities and reading disabilities; All people, including those who do not identify as disabledElements that have the same functionality across multiple web pages are consistently identified. For example, a search box at the top of the site should always be labeled the same way.
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3.3.1 Error Identification
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disabilities and reading disabilities; All people, including those who do not identify as disabledRequired form elements or form elements that require a specific format, value, or length provide this information within the element's label.
Form validation errors are efficient, intuitive, and accessible. The error is clearly identified, quick access to the problematic element is provided, and the user can easily fix the error and resubmit the form.
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3.3.2 Labels or Instructions
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disabilities and reading disabilities; All people, including those who do not identify as disabledSufficient labels, cues, and instructions for required interactive elements are provided via instructions, examples, properly positioned form labels, and/or fieldsets/legends.
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3.3.3 Error Suggestion
2.0AAScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disabilities and reading disabilities; All people, including those who do not identify as disabledIf an input error is detected (via client-side or server-side validation), suggestions are provided for fixing the input in a timely and accessible manner.
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3.3.4 Error Prevention (Legal, Financial, Data)
2.0AAScreen reader users (blind, low vision, and neurodivergent people); People with cognitive disabilities and reading disabilities; All people, including those who do not identify as disabledIf the user can change or delete legal, financial, or test data, the changes/deletions can be reversed, verified, or confirmed.
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4.1.1 Parsing
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with low vision using screen magnifiers; People with dexterity impairment using voice controlSignificant HTML validation/parsing errors are avoided. Check at http://validator.w3.org/
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4.1.2 Name, Role, Value
2.0AScreen reader users (blind, low vision, and neurodivergent people); People with low vision using screen magnifiers; People with dexterity impairment using voice controlMarkup is used in a way that facilitates accessibility. This includes following the HTML specifications and using forms, form labels, frame titles, etc. appropriately.
ARIA is used appropriately to enhance accessibility when HTML is not sufficient.
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4.1.3 Status Messages
2.1AAScreen reader users (blind, low vision, and neurodivergent people)If an important status message is presented and focus is not set to that message, the message must be announced to screen reader users, typically via an ARIA alert or live region.
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