Accessibility

Non-text Content: All non-text content that is presented to the user has a text alternative that serves the equivalent purpose

Audio-only and Video-only (Prerecorded): Text alternatives for all pre-recorded audio-only and video-only content

Captions (Prerecorded): Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labeled as such

Audio Description or Media Alternative (Prerecorded): An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media, except when the media is a media alternative for text and is clearly labeled as such

Captions (Live): Captions are provided for all live audio content in synchronized media

Audio Description (Prerecorded): Audio description is provided for all prerecorded video content in synchronized media

Info and Relationships: Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text

Meaningful Sequence: When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined

Sensory Characteristics: Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, size, visual location, orientation, or sound

Use of Color: Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element

Audio Control: If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level

Contrast (Minimum): The visual presentation of text and images of text has a contrast ratio of at least 4.5:1

Resize text: Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality

Images of Text: If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text

Keyboard: All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints

No Keyboard Trap: If keyboard focus can be moved to a component of the page using a keyboard interface, then focus can be moved away from that component using only a keyboard interface, and, if it requires more than unmodified arrow or tab keys or other standard exit methods, the user is advised of the method for moving focus away

Timing Adjustable: For each time limit that is set by the content, at least one of the following is true:

• Turn off: The user is allowed to turn off the time limit before encountering it
• Adjust: The user is allowed to adjust the time limit before encountering it over a wide range that is at least ten times the length of the default setting
• Extend: The user is warned before time expires and given at least 20 seconds to extend the time limit with a simple action (for example, "press the space bar"), and the user is allowed to extend the time limit at least ten times
• Real-time Exception: The time limit is a required part of a real-time event (for example, an auction), and no alternative to the time limit is possible
• Essential Exception: The time limit is essential and extending it would invalidate the activity
• 20 Hour Exception: The time limit is longer than 20 hours

Pause, Stop, Hide: For moving, blinking, scrolling, or auto-updating information, all of the following are true:

• Moving, blinking, scrolling: For any moving, blinking or scrolling information that (1) starts automatically, (2) lasts more than five seconds, and (3) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it unless the movement, blinking, or scrolling is part of an activity where it is essential
• Auto-updating: For any auto-updating information that (1) starts automatically and (2) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it or to control the frequency of the update unless the auto-updating is part of an activity where it is essential

Three Flashes or Below Threshold: Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds

Bypass Blocks: A mechanism is available to bypass blocks of content that are repeated on multiple Web pages

Page Titled: Web pages have titles that describe topic or purpose

Focus Order: If a Web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability

Link Purpose (In Context): The purpose of each link can be determined from the link text alone or from the link text together with its programmatically determined link context, except where the purpose of the link would be ambiguous to users in general

Multiple Ways: More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process

Headings and Labels: Headings and labels describe topic or purpose

Focus Visible: Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible

Language of Page: The default human language of each Web page can be programmatically determined

On Focus: When any component receives focus, it does not initiate a change of context

Consistent Navigation: Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user

Consistent Identification: Components that have the same functionality within a set of Web pages are identified consistently

Error Identification: If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text

Labels or Instructions: Labels or instructions are provided when content requires user input

Error Suggestion: If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content

Error Prevention (Legal, Financial, Data): For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true:

• Reversible: Submissions are reversible
• Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them
• Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission