Quick Table of Contents

WCAG 2.0 Guidelines

Principle 1: Content must be perceivable.

Guideline 1.1 Provide text alternatives for all non-text content.

Level 1 Success Criteria for Guideline 1.1

1.1.1 For non-text content that is used to convey information, text alternatives identify the non-text content and convey the same information. For multimedia, provide a text-alternative that identifies the multimedia. For live audio-only and live video-only, conform to success criterion 1.1.5. [How to meet 1.1.1]

Note: For requirements for synchronized alternatives for multimedia refer to Guideline 1.2 Provide synchronized alternatives for multimedia.

1.1.2 For non-text content that is functional, text alternatives serve the same purpose as the non-text content. If text alternatives can not serve the same purpose as the functional non-text content, text alternatives identify the purpose of the functional non-text content [How to meet 1.1.2]

1.1.3 For non-text content that is intended to create a specific sensory experience, text alternatives at least identify the non-text content with a descriptive label. [How to meet 1.1.3]

1.1.4 Non-text content that is not functional, is not used to convey information, and does not create a specific sensory experience is implemented such that it can be ignored by assistive technology. [How to meet 1.1.4]

1.1.5 For live audio-only or video-only content, text alternatives at least identify the purpose of the content with a descriptive label. [How to meet 1.1.5]

Note: Refer to Guideline 1.2 Provide synchronized alternatives for multimedia. for guidance on content that combines live audio and video.

Level 2 Success Criteria for Guideline 1.1

(No level 2 success criteria for this guideline.)

Level 3 Success Criteria for Guideline 1.1

1.1.6 For prerecorded multimedia content, a combined document containing both captions and transcripts of audio descriptions of video is available. [How to meet 1.1.6]

Guideline 1.1 (text-equiv) Issues

Guideline 1.2 Provide synchronized alternatives for multimedia.

Level 1 Success Criteria for Guideline 1.2

1.2.1 Captions are provided for prerecorded multimedia. [How to meet 1.2.1]

Editorial Note: The working group is seeking comment on the following proposal:

  1. Change 1.2.1 to " Provide captions OR provide a text transcript of all audio intermixed with a text description of what is happening visually."

so authors have an option of providing captions OR a text script. Then, at Level 2, require captions.

1.2.2 Audio descriptions of video are provided for prerecorded multimedia [How to meet 1.2.2]

Editorial Note: The working group is seeking comment on the following proposal:

  1. Change 1.2.2 to " Provide audio descriptions OR provide a text transcript of all audio intermixed with a text description of what is happening visually."

so authors have an option of providing audio descriptions OR a text script. Then, at Level 2, require audio descriptions.

Level 2 Success Criteria for Guideline 1.2

1.2.3 Real-time captions are provided for live multimedia. [How to meet 1.2.3]

Level 3 Success Criteria for Guideline 1.2

1.2.5 Extended audio descriptions of video are provided for prerecorded multimedia. [How to meet 1.2.5]

Guideline 1.2 (media-equiv) Issues

Guideline 1.3 Ensure that information, functionality, and structure can be separated from presentation.

Level 1 Success Criteria for Guideline 1.3

1.3.1 Perceivable structures within the content can be programmatically determined. [How to meet 1.3.1]

1.3.2 When information is conveyed by color, the color can be programmatically determined or the information is also conveyed through another means that does not depend on the user's ability to differentiate colors. [How to meet 1.3.2]

Level 2 Success Criteria for Guideline 1.3

1.3.3 Information that is conveyed by variations in presentation of text is also conveyed in text or the variations in presentation of text can be programmatically determined. [How to meet 1.3.3]

1.3.4 Any information that is conveyed by color is visually evident when color is not available. [How to meet 1.3.4]

Level 3 Success Criteria for Guideline 1.3

1.3.5 When content is arranged in a sequence that affects its meaning, that sequence can be programmatically determined. [How to meet 1.3.5]

1.3.6 Information required to understand and operate content does not rely on shape, size, visual location, or orientation of components. [How to meet 1.3.6]

Guideline 1.3 (content-structure-separation) Issues

Guideline 1.4 Make it easy to distinguish foreground information from background images or sounds. [level 2 guideline]

Level 1 Success Criteria for Guideline 1.4

(No level 1 success criteria for this guideline.)

Level 2 Success Criteria for Guideline 1.4

1.4.1 Text or diagrams, and their background, must have a luminosity contrast ratio of at least 5:1. [How to meet 1.4.1]

1.4.2 A mechanism is available to turn off background audio that plays automatically. [How to meet 1.4.2]

Level 3 Success Criteria for Guideline 1.4

1.4.3 Text or diagrams, and their background, must have a luminosity contrast ratio of at least 10:1. [How to meet 1.4.3]

1.4.4 Audio content does not contain background sounds or the background sounds are at least 20 decibels lower than the foreground audio content, with the exception of occasional sound effects. [How to meet 1.4.4]

Note: A 20 decibel difference in sound level is roughly 4 times quieter (or louder). Background sound that meets this requirement will be approximately four times (4x) quieter than the foreground audio content.

Guideline 1.4 (visual-audio-contrast) Issues

Principle 2: Interface elements in the content must be operable.

Guideline 2.1 Make all functionality operable via a keyboard interface.

Level 1 Success Criteria for Guideline 2.1

2.1.1 All functionality of the content is operable in a non time-dependent manner through a keyboard interface, except where the task requires analog, time-dependent input. [How to meet 2.1.1]

Note: This does not preclude and should not discourage the support of other input methods (such as a mouse) in addition to keyboard operation.

Note: MouseKeys does not satisfy this success criterion.

Level 2 Success Criteria for Guideline 2.1

(No level 2 success criteria for this guideline.)

Level 3 Success Criteria for Guideline 2.1

2.1.2 All functionality of the content is designed to be operated through a keyboard interface. [How to meet 2.1.2]

Guideline 2.1 (keyboard-operation) Issues

Guideline 2.2 Allow users to control time limits on their reading or interaction.

Level 1 Success Criteria for Guideline 2.2

2.2.1 For each time-out that is a function of the content, at least one of the following is true: [How to meet 2.2.1]

  • the user is allowed to deactivate the time-out or;

  • the user is allowed to adjust the time-out over a wide range which is at least ten times the length of the default setting or;

  • the user is warned before time expires and given at least 20 seconds to extend the time-out with a simple action (for example, "hit any key") and the user is allowed to extend the timeout at least 10 times or;

  • the time-out is an important part of a real-time event (for example, an auction), and no alternative to the time-out is possible or;

  • the time-out is part of an activity where timing is essential (for example, competitive gaming or time-based testing) and time limits can not be extended further without invalidating the activity.

Editorial Note: The Working Group is considering adding techniques and/or modifying the success criterion to ensure additional accessibility features are employed for events where no alternative to a timeout is possible or where timing is essential.

Level 2 Success Criteria for Guideline 2.2

2.2.3 Content can be paused by the user unless the timing or movement is part of an activity where timing or movement is essential. [How to meet 2.2.3]

Level 3 Success Criteria for Guideline 2.2

2.2.4 Except for real-time events, timing is not an essential part of the event or activity presented by the content. [How to meet 2.2.4]

2.2.5 Interruptions, such as updated content, can be postponed or suppressed by the user, except those involving an emergency. [How to meet 2.2.5]

2.2.6 When an authenticated session has an inactivity timeout, the user can continue the activity without loss of data after re-authenticating. [How to meet 2.2.6]

Guideline 2.2 (time-limits) Issues

Guideline 2.3 Allow users to avoid content that could cause seizures due to photosensitivity.

Level 1 Success Criteria for Guideline 2.3

2.3.1 When content violates either the general flash threshold or thered flash threshold, users are warned in a way that they can avoid it. [How to meet 2.3.1]

Level 2 Success Criteria for Guideline 2.3

2.3.2 Content does not violate general flash threshold or red flash threshold. [How to meet 2.3.2]

Level 3 Success Criteria for Guideline 2.3

(No level 3 success criteria for this guideline.)

Guideline 2.3 (seizure) Issues

Guideline 2.4 Provide mechanisms to help users find content, orient themselves within it, and navigate through it.

Level 1 Success Criteria for Guideline 2.4

Level 2 Success Criteria for Guideline 2.4

Level 3 Success Criteria for Guideline 2.4

Guideline 2.4 (navigation-mechanisms) Issues

Guideline 2.5 Help users avoid mistakes and make it easy to correct them.

Level 1 Success Criteria for Guideline 2.5

2.5.1 If an input error is detected, the error is identified and described to the user in text. [How to meet 2.5.1]

Level 2 Success Criteria for Guideline 2.5

2.5.2 If an input error is detected and suggestions for correction are known and can be provided without jeopardizing the security or purpose of the content, the suggestions are provided to the user. [How to meet 2.5.2]

2.5.3 For forms that cause legal or financial transactions to occur, that modify or delete data in remote data storage systems, or that submit test responses, at least one of the following is true: [How to meet 2.5.3]

  1. Actions are reversible.

  2. Actions are checked for input errors before going on to the next step in the process.

  3. The user is able to review and confirm or correct information before submitting it.

Level 3 Success Criteria for Guideline 2.5

2.5.4 Context-sensitive help is available for text input. [How to meet 2.5.4]

Guideline 2.5 (minimize-error) Issues

Principle 3: Content and controls must be understandable.

Guideline 3.1 Make text content readable and understandable.

Level 1 Success Criteria for Guideline 3.1

3.1.1 The primary natural language or languages of the delivery unit can be programmatically determined. [How to meet 3.1.1]

Level 2 Success Criteria for Guideline 3.1

3.1.2 The natural language of each foreign passage or phrase in the content can be programmatically determined. [How to meet 3.1.2]

Note: This requirement does not apply to individual words or to phrases that have become part of the primary language of the content.

Level 3 Success Criteria for Guideline 3.1

3.1.3 A mechanism is available for identifying specific definitions of words used in an unusual or restricted way, including idioms and jargon. [How to meet 3.1.3]

3.1.4 A mechanism for finding the expanded form of abbreviations is available. [How to meet 3.1.4]

3.1.5 When text requires reading ability more advanced than the lower secondary education level, one or more of the following types of supplemental content is available: [How to meet 3.1.5]

  1. A text summary that requires reading ability less advanced than the lower secondary education level.

  2. Graphical illustrations of concepts or processes that must be understood in order to use the content.

  3. A spoken version of the text content.

3.1.6 When a page or other delivery unit is navigated sequentially, elements receive focus in an order that follows relationships and sequences in the content. [How to meet 3.1.6]

Guideline 3.1 (meaning) Issues

Guideline 3.2 Make the placement and functionality of content predictable.

Level 1 Success Criteria for Guideline 3.2

3.2.1 When any component receives focus, it does not cause a change of context. [How to meet 3.2.1]

Note: Refer to Guideline 2.1 Make all functionality operable via a keyboard interface. for requirements for making all functionality operable via a keyboard interface.

Level 2 Success Criteria for Guideline 3.2

3.2.2 Changing the setting of any input field does not automatically cause a change of context . [How to meet 3.2.2]

3.2.3 Components that are repeated on multiple delivery units within a set of delivery units occur in the same relative order each time they are repeated. [How to meet 3.2.3]

3.2.4 Components that have the same functionality in multiple delivery units within a set of delivery units are identified consistently. [How to meet 3.2.4]

Level 3 Success Criteria for Guideline 3.2

3.2.5 Changes of context are initiated only by user request. [How to meet 3.2.5]

Guideline 3.2 (consistent-behavior) Issues

Principle 4: Content must be robust enough to work with current and future technologies.

Guideline 4.1 Use technologies according to specification.

Level 1 Success Criteria for Guideline 4.1

4.1.1 Delivery units can be parsed unambiguously and the relationships in the resulting data structure are also unambiguous. [How to meet 4.1.1]

Level 2 Success Criteria for Guideline 4.1

(No level 2 success criteria for this guideline.)

Level 3 Success Criteria for Guideline 4.1

(No level 3 success criteria for this guideline.)

Guideline 4.1 (use-spec) Issues

Guideline 4.2 Ensure that user interfaces are accessible or provide an accessible alternative(s)

Level 1 Success Criteria for Guideline 4.2

4.2.1 If content does not meet all level 1 success criteria, then an alternate version is available from the same URI that does meet all level 1 success criteria. [How to meet 4.2.1]

4.2.2 Content meets the following criteria even if the content uses a technology that is not in the chosen baseline: [How to meet 4.2.2]

  1. When content violates either the general flash threshold or thered flash threshold, users are warned in a way that they can avoid it.

  2. If the user can enter the content using the keyboard, then the user can exit the content using the keyboard.

4.2.3 The role, state, and value can be programmatically determined for every user interface component of the web content that accepts input from the user or changes dynamically in response to user input or external events. [How to meet 4.2.3]

4.2.4 The label of each user interface control that accepts input from the user can be programmatically determined and is explicitly associated with the control. [How to meet 4.2.4]

4.2.5 The content and properties of user interface elements that can be changed via the user interface can also be directly changed programmatically. [How to meet 4.2.5]

Note: Some examples of standardized properties that typically can be changed by the user interface include its value, whether it is currently selected, and whether it currently has the focus.

Editorial Note: The working group is still considering whether this criterion should be included and, if so, at what level.

4.2.6 Changes to content, structure, selection, focus, attributes, values, state, and relationships can be programmatically determined. [How to meet 4.2.6]

Level 2 Success Criteria for Guideline 4.2

(No level 2 success criteria for this guideline.)

Level 3 Success Criteria for Guideline 4.2

4.2.7 Content implemented using technologies outside of the chosen baseline satisfies all level 1 and 2 WCAG requirements supported by the technologies. [How to meet 4.2.7]

Guideline 4.2 (technology-supports-access) Issues