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WCAG 2.0 Quick Reference (17 May 2007)

A customizable list of WCAG 2.0 requirements (success criteria) and techniques

Introduction

This customizable Web Content Accessibility Guidelines (WCAG) 2.0 Quick Reference provides a list of success criteria, techniques and failures based on technologies and conformance levels speified above. When all options are selected, this Quick Reference includes all of the WCAG 2.0 guidelines and success criteria along with the techniques that the WCAG Working Group has identified as being sufficient to meet the success criteria. If there are any common known failures for a success criterion, or advisory techniques they are listed as well. The list of technology types includes the technologies that are currently available. Others will be added over time.

Note that all techniques are informative. The "sufficient techniques" listed below are deemed sufficient by the WCAG Working Group to meet the success criteria, and this can be helpful when developing content or determining conformance to the WCAG 2.0 success criteria. However, it is not necessary to use these particular techniques. If techniques are used other than those listed by the Working Group, then some other method for establishing the technique's ability to meet the success criteria would be needed. New techniques can be submitted to the Working Group at any time.

In addition to the 'sufficient techniques', there are also advisory techniques that go beyond WCAG 2.0's requirements. Even content that completely conforms to WCAG will not be fully accessible to every person with a disability, especially people with language, learning, and cognitive disabilities, or multiple sever disabilities. The WCAG 2.0 advisory techniques and other techniques still in development can help to address the needs of these groups.

For additional information on WCAG 2.0 and its supporting documents see Overview of WCAG 2.0 Documents.

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Table of Contents

WCAG 2.0 Guidelines

Guideline 1.1: Provide text alternatives for any non-text content so that it can be changed into other forms people need such as large print, braille, speech, symbols or simpler language Understanding Guideline 1.1

1.1.1 Non-text Content: All non-text content has a text alternative that presents equivalent information, except for the situations listed below. (Level A)Understanding Success Criterion 1.1.1

  • Controls-Input: If non-text content is a control or accepts user input, then it has a name that describes its purpose. (See also Guideline 4.1.)

  • Media, Test, Sensory: If non-text content is multimedia , live audio-only or live video-only content, a test or exercise that must be presented in non-text format , or primarily intended to create a specific sensory experience , then text alternatives at least identify the non-text content with a descriptive text label. (For multimedia, see also Guideline 1.2.)

  • CAPTCHA: If the purpose of non-text content is to confirm that content is being accessed by a person rather than a computer, then text alternatives that identify and describe the purpose of the non-text content are provided and alternative forms in different modalities are provided to accommodate different disabilities.

  • Decoration, Formatting, Invisible: If non-text content is pure decoration, or used only for visual formatting, or if it is not presented to users, then it is implemented such that it can be ignored by assistive technology.

Sufficient Techniques for 1.1.1 (for the technologies you checked above)
Situation A: If a short description can serve the same purpose and present the same information as the non-text content:

  1. G94: Providing short text alternative for non-text content that serves the same purpose and presents the same information as the non-text content using a short text alternative technique listed below

Situation B: If a short description can not serve the same purpose and present the same information as the non-text content (e.g. a chart or diagram):

  1. G95: Providing short text alternatives that provide a brief description of the non-text content using a short text alternative technique listed below AND one of the following techniques for long description:

Situation C: If non-text content is a control or accepts user input:

  1. G82: Providing a text alternative that identifies the purpose of the non-text content using a short text alternative technique listed below

  2. Using HTML form controls and links (future link)

  3. H44: Using label elements to associate text labels with form controls (HTML)

  4. H65: Using the title attribute to identify form controls when the label element cannot be used (HTML)

  5. Using (X)HTML according to spec (future link)

Situation D: If non-text content is multimedia; live audio-only or live video-only content; a test or exercise that must use a particular sense; or primarily intended to create a specific sensory experience:

  1. Providing a descriptive label using a short text alternative technique listed below

  2. G68: Providing a descriptive label that describes the purpose of live audio-only and live video-only content using a short text alternative technique listed below

  3. G100: Providing the accepted name or a descriptive name of the non-text content using a short text alternative technique listed below

Situation E: If non-text content is a CAPTCHA:

  1. G143: Providing a text alternative that describes the purpose of the CAPTCHA AND G144: Ensuring that the Web Page contains another CAPTCHA serving the same purpose using a different modality

Situation F: If the non-text content should be ignored by assistive technology:

  1. Implementing or marking the non-text content so that it will be ignored by assistive technology using one of the technology-specific techniques listed below

Providing short text alternatives in HTML
Providing long text alternatives in HTML
Common Failures Identified by the Working Group for 1.1.1
Advisory Techniques for 1.1.1
General Techniques for Informative Non-Text Content (Advisory)

  • Identifying informative non-text content (future link)

  • Keeping short descriptions short (future link)

  • Describing images that include text (future link)

  • Providing a longer description of the non-text content where only a descriptive label is required using a technology-specific technique (for an accessibility-supported content technology) for long description listed above (future link)

General Techniques for Live Non-Text Content (Advisory)

  • Linking to textual information that provides comparable information (e.g. for a traffic Webcam, a municipality could provide a link to the text traffic report.) (future link)

  • Providing a transcript of a live audio only presentation after the fact (future link)

HTML Techniques (Advisory)

  • H46: Using noembed with embed (HTML)

  • Writing for browsers that do not support frame (future link)

  • Providing alternative content for iframe (future link)

  • Providing text and non-text alternatives for object (future link)

  • Not using long descriptions for iframe (future link)

  • Providing redundant text links for client-side image maps (future link)

CSS Techniques (Advisory)

  • Using CSS margin and padding rules instead of spacer images (future link)

  • Using CSS background, :before or :after rules for decorative images instead of img elements (future link)

  • Displaying empty table cells (future link)

Guideline 1.2: Provide synchronized alternatives for multimedia Understanding Guideline 1.2

Guideline 1.3: Create content that can be presented in different ways (for example spoken aloud, simpler layout, etc.) without losing information or structure Understanding Guideline 1.3

1.3.1 Info and Relationships: Information and relationships conveyed through presentation can be programmatically determined or are available in text , and notification of changes to these is available to user agents, including assistive technologies. (Level A)Understanding Success Criterion 1.3.1

Sufficient Techniques for 1.3.1 (for the technologies you checked above)
Situation A: The technology provides semantic structure to make information and relationships conveyed through presentation programmatically determinable:

  1. G115: Using semantic elements to mark up structure AND H49: Using semantic markup to mark emphasized or special text (HTML)

  2. G117: Using text to convey information that is conveyed by variations in presentation of text

  3. Separating information and structure from presentation to enable modification of presentation without altering content (future link)

  4. Making information and relationships conveyed through presentation programmatically determinable using the following techniques:

Situation B: The technology in use does NOT provide the semantic structure to make the information and relationships conveyed through presentation programmatically determinable:

  1. G117: Using text to convey information that is conveyed by variations in presentation of text

  2. Making information and relationships conveyed through presentation programmatically determinable or available in text using the following techniques:

Common Failures Identified by the Working Group for 1.3.1
Advisory Techniques for 1.3.1

1.3.2 Meaningful Sequence: When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined and sequential navigation of interactive components is consistent with that sequence. (Level A)Understanding Success Criterion 1.3.2

Sufficient Techniques for 1.3.2 (for the technologies you checked above)

  1. G57: Ordering the content in a meaningful sequence for all the content in the Web page

  2. Marking sequences in the content as meaningful using one of the following techniques AND G57: Ordering the content in a meaningful sequence for those sequences

Common Failures Identified by the Working Group for 1.3.2
Advisory Techniques for 1.3.2

  • Using left-justified text for languages that are written left to right and right-justified text for languages that are written right-to-left (future link)

  • Using appropriate justification for languages that are written right-to-left (future link)

  • Providing a link to linearized rendering (future link)

  • Providing a style switcher between style sheets that affect presentation order (future link)

1.3.3 Size, Shape, Location: Instructions provided for understanding and operating content do not rely on shape, size, visual location, or orientation of components. (Level A)Understanding Success Criterion 1.3.3

Sufficient Techniques for 1.3.3 (for the technologies you checked above)

  1. G96: Providing textual identification of items that otherwise rely only on shape and/or position to be understood

Common Failures Identified by the Working Group for 1.3.3
Advisory Techniques for 1.3.3

  • Using an image with a text alternative for graphical symbols instead of a Unicode font glyph with the desired graphical appearance but different meaning (future link)

Guideline 1.4: Make it easier for people with disabilities to see and hear content including separating foreground from background Understanding Guideline 1.4

1.4.1 Use of Color: Any information that is conveyed by color differences is also simultaneously visually evident without the color differences. (Level A)Understanding Success Criterion 1.4.1

Sufficient Techniques for 1.4.1 (for the technologies you checked above)
Situation A: If the color of particular words is used to indicate information:

  1. G14: Ensuring that color-encoded information is also available in text

  2. G122: Including a text cue whenever color cues are used

  3. Ensuring that when text color is used to convey information, the text style is visually differentiated without color (future link)

Situation B: If color is used within an image to convey information:

  1. G111: Using color and pattern

  2. G14: Ensuring that color-encoded information is also available in text

Common Failures Identified by the Working Group for 1.4.1
Advisory Techniques for 1.4.1

  • Conveying information redundantly using color (future link)

  • Changing the background color or border of the element with focus (future link)

1.4.2 Audio Turnoff: If any audio 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 which can be set independently of the system volume. (Level A)Understanding Success Criterion 1.4.2

Sufficient Techniques for 1.4.2 (for the technologies you checked above)

  1. G60: Playing a sound that turns off automatically within three seconds

  2. Playing sounds only on user request (future link)

  3. Providing a control near the top of the Web page that turns off sounds that play automatically (future link)

  4. Providing a user interface control to pause or stop multimedia (future link)

Common Failures Identified by the Working Group for 1.4.2
Advisory Techniques for 1.4.2

  • Providing a sitewide preference to turn off audio in addition to providing a control near the top of the Web page that turns off sounds that play automatically (future link)

1.4.3 Contrast (Minimum): Text (and images of text) have a contrast ratio of at least 5:1, except if the text is pure decoration. Larger-scale text or images of text can have a contrast ratio of 3:1. (Level AA)Understanding Success Criterion 1.4.3

Sufficient Techniques for 1.4.3 (for the technologies you checked above)
Situation A: text is less than 18 point if not bold and less than 14 point if bold

  1. G18: Ensuring that a contrast ratio of at least 5:1 exists between text and background behind the text

  2. H21: Not specifying background color, not specifying text color, and not using CSS that changes those defaults (HTML)

Situation B: text is as least 18 point if not bold and at least 14 point if bold

  1. G145: Ensuring that a contrast ratio of at least 3:1 exists between text and background behind the text

  2. H21: Not specifying background color, not specifying text color, and not using CSS that changes those defaults (HTML)

Common Failures Identified by the Working Group for 1.4.3
Advisory Techniques for 1.4.3

  • Using a higher contrast value for text that is over a patterned background (future link)

  • Creating foreground and background contrast (future link)

  • Using a light pastel background rather than a white background behind black text (future link)

  • Using Unicode text and style sheets instead of images of text (future link)

  • Using a higher contrast values for lines in diagrams (future link)

  • Using greater contrast level for red-black text/background combinations

  • Using colors that are composed predominantly of mid spectral components for the light and spectral extremes (blue and red wavelengths) for the dark

1.4.4 Resize text: Visually rendered text can be resized without assistive technology up to 200 percent and down to 50 percent without loss of content or functionality. (Level AA)Understanding Success Criterion 1.4.4

Sufficient Techniques for 1.4.4 (for the technologies you checked above)

  1. G142: Using a technology that has commonly-available user agents that support zoom

  2. Ensuring that text containers resize when the text resizes AND using measurements that are relative to other measurements in the content by using one or more of the following techniques:

  3. Providing controls on the Web page that incrementally change the size of the text (future link)

  4. Providing options within the content to switch between layouts that use a variety of font sizes (future link)

Common Failures Identified by the Working Group for 1.4.4
Advisory Techniques for 1.4.4

  • Providing large fonts by default (future link)

  • Avoiding the use of text in raster images (future link)

  • Using page-percent for container sizes (future link)

  • Avoiding scaling font sizes smaller than the user-agent default (future link)

    Note: The author won't actually know the font size, but should avoid percentage scaling that results in less than 100%

  • Avoiding justified text (future link)

  • Providing sufficient inter-line and inter-column spacing (future link)

1.4.5 Contrast (Enhanced): Text (and images of text) have a contrast ratio of at least 7:1, except if the text is pure decoration. Larger-scale text or images of text can have a contrast ratio of 5:1. (Level AAA)Understanding Success Criterion 1.4.5

Sufficient Techniques for 1.4.5 (for the technologies you checked above)
Situation A: text is less than 18 point if not bold and less than 14 point if bold

  1. G17: Ensuring that a contrast ratio of at least 7:1 exists between text and background behind the text

  2. H21: Not specifying background color, not specifying text color, and not using CSS that changes those defaults (HTML)

Situation B: text is as least 18 point if not bold and at least 14 point if bold

  1. G18: Ensuring that a contrast ratio of at least 5:1 exists between text and background behind the text

  2. H21: Not specifying background color, not specifying text color, and not using CSS that changes those defaults (HTML)

Common Failures Identified by the Working Group for 1.4.5
Advisory Techniques for 1.4.5

  • Using a higher contrast value for text that is over a patterned background (future link)

  • Using Unicode text and style sheets instead of images of text (future link)

  • Using a light pastel background rather than a white background behind black text (future link)

  • Using a higher contrast values for lines in diagrams (future link)

  • Using greater contrast level for red-black text/background combinations

  • Using colors that are composed predominantly of mid spectral components for the light and spectral extremes (blue and red wavelengths) for the dark

1.4.6 Low or No Background Audio: Audio content that contains speech in the foreground does not contain background sounds, background sounds can be turned off, or background sounds are at least 20 decibels lower than the foreground speech content, with the exception of occasional sound effects. (Level AAA)Understanding Success Criterion 1.4.6

Note: Background sound that meets this requirement will be approximately one quarter as loud as the foreground speech content.

Sufficient Techniques for 1.4.6 (for the technologies you checked above)

  1. G56: Mixing audio files so that non-speech sounds are at least 20 decibels lower than the speech audio content

  2. Not including audio content (future link)

Advisory Techniques for 1.4.6

  • Providing a way for users to adjust auditory levels of foreground and background sound independently (future link)

1.4.7 Resize and Wrap: Visually rendered text can be resized without assistive technology up to 200 percent and down to 50 percent without loss of content or functionality and in a way that does not require the user to scroll horizontally. (Level AAA)Understanding Success Criterion 1.4.7

Sufficient Techniques for 1.4.7 (for the technologies you checked above)

  1. G146: Using liquid layout AND ensuring that text containers resize when the text resizes AND using measurements that are relative to other measurements in the content by using one or more of the following techniques:

  2. Providing options within the content to switch between layouts that use a variety of font sizes (future link)

  3. Using single-column layouts (future link)

Common Failures Identified by the Working Group for 1.4.7
Advisory Techniques for 1.4.7

  • Providing large fonts by default (future link)

  • Avoiding the use of text in raster images (future link)

  • Using page-percent for container sizes (future link)

  • Avoiding scaling font sizes smaller than the user-agent default (future link)

    Note: The author won't actually know the font size, but should avoid percentage scaling that results in less than 100%

  • Avoiding justified text (future link)

  • Providing sufficient inter-line and inter-column spacing (future link)

Guideline 2.1: Make all functionality available from a keyboard Understanding Guideline 2.1

2.1.1 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. (Level A)Understanding Success Criterion 2.1.1

Note 1: This exception relates to the underlying function, not the input technique. For example, if using handwriting to enter text, the input technique (handwriting) requires path dependent input but the underlying function (text input) does not.

Note 2: This does not forbid and should not discourage providing mouse input or other input methods in addition to keyboard operation.

Sufficient Techniques for 2.1.1 (for the technologies you checked above)

  1. G21: Ensuring that users are not trapped in content AND ensuring keyboard control by using one of the following techniques.

    • Using HTML form controls and links (future link)

  2. G21: Ensuring that users are not trapped in content AND G90: Providing keyboard-triggered event handlers using one of the following techniques:

Common Failures Identified by the Working Group for 2.1.1
Advisory Techniques for 2.1.1

  • Providing keyboard access to important links and form controls (future link)

  • Using unique letter combinations to begin each item of a list (future link)

  • Choosing the most abstract event handler (future link)

  • Using the onactivate event (future link)

  • Avoiding use of common user-agent keyboard commands for other purposes (future link)

2.1.2 Keyboard (No Exception): All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes. (Level AAA)Understanding Success Criterion 2.1.2

Sufficient Techniques for 2.1.2 (for the technologies you checked above)

  1. No additional techniques exist for this Success Criterion. Follow techniques for Success Criterion 2.1.1. If that is not possible because there is a requirement for analog, time-dependent input, then it is not possible to meet this Level AAA Success Criterion.

Guideline 2.2: Provide users with disabilities enough time to read and use content Understanding Guideline 2.2

2.2.1 Timing: For each time limit that is set by the content , at least one of the following is true: (Level A)Understanding Success Criterion 2.2.1

  • Turn off: the user is allowed to turn off the time limit before encountering it; or

  • 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; or

  • 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, "hit any key"), and the user is allowed to extend the time limit at least ten times; or

  • 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; or

  • Essential Exception: the time limit is part of an activity where timing is essential (for example, time-based testing) and time limits can not be extended further without invalidating the activity.

Sufficient Techniques for 2.2.1 (for the technologies you checked above)
Situation A: If there are session time limits:

  1. G133: Providing a checkbox on the first page of a multipart form that allows users to ask for longer session time limit or no session time limit

Situation B: If a time limit is controlled by a script on the page:

  1. Providing a way for the user to turn the time limit off (future link)

  2. Providing the user with a means to set the time limit to 10 times the default time limit (future link)

  3. SCR16: Providing a script that warns the user a time limit is about to expire (SCRIPT) AND SCR1: Allowing the user to extend the default time limit (SCRIPT)

Common Failures Identified by the Working Group for 2.2.1
Advisory Techniques for 2.2.1

  • Using a script to poll the server and notify a user if a time limit is present (future link)

  1. G11: Creating content that blinks for less than 3 seconds

  2. Using a technology to include blinking content that can be turned off via the user agent (future link)

  3. Using a control in the Web page that stops blinking content (future link) using one of the following techniques:

  • Providing a mechanism to stop all content that blinks within a Web page (future link)

  • Providing the user with a means to stop moving content even if it stops automatically within 3 seconds (future link)

2.2.3 Pausing: Moving, blinking, scrolling, or auto-updating information can be paused by the user unless it is part of an activity where timing or movement is essential. Moving content that is pure decoration can be stopped by the user. (Level AA)Understanding Success Criterion 2.2.3

Sufficient Techniques for 2.2.3 (for the technologies you checked above)

  1. G4: Allowing the content to be paused and restarted from where it was stopped

  2. Using script to scroll content, and providing a mechanism to pause it (future link)

  3. Allowing purely decorative content to be stopped (future link)

Common Failures Identified by the Working Group for 2.2.3

2.2.4 Timing: Timing is not an essential part of the event or activity presented by the content, except for non-interactive multimedia and real-time events. (Level AAA)Understanding Success Criterion 2.2.4

Sufficient Techniques for 2.2.4 (for the technologies you checked above)

  1. G5: Allowing users to complete an activity without any time limit

2.2.5 Interruptions: Interruptions, such as updated content, can be postponed or suppressed by the user, except interruptions involving an emergency. (Level AAA)Understanding Success Criterion 2.2.5

Sufficient Techniques for 2.2.5 (for the technologies you checked above)

  1. G75: Providing a mechanism to postpone any updating of content

  2. Allowing users to request updates instead of automatically updating content (future link)

  3. SCR14: Using scripts to make nonessential alerts optional (SCRIPT)

Common Failures Identified by the Working Group for 2.2.5

2.2.6 Re-authenticating: When an authenticated session expires, the user can continue the activity without loss of data after re-authenticating. (Level AAA)Understanding Success Criterion 2.2.6

Sufficient Techniques for 2.2.6 (for the technologies you checked above)

  1. Providing options to continue without loss of data using one of the following techniques:

Note: Refer to Techniques for Addressing Success Criterion 2.2.1 for techniques related to providing notifications about time limits.

Common Failures Identified by the Working Group for 2.2.6

Guideline 2.3: Do not create content that is known to cause seizures Understanding Guideline 2.3

2.3.1 Three Flashes or Below Threshold: Content does 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. (Level A)Understanding Success Criterion 2.3.1

Sufficient Techniques for 2.3.1 (for the technologies you checked above)
Situation A: Web content server over the Internet for general viewing

  1. Using all possible 341 x 256 pixel rectangles on 1024 x 768 pixel display to represent a 10 degree field of view at normal viewing distance AND G15: Ensuring that content does not violate the general flash threshold or red flash threshold

    Note: There is a tool that is available to carry out this test.

  2. G19: Ensuring that no component of the content flashes more than three times in any 1-second period

Situation B: Web content designed for a specific large-scale display where size and viewing distance is known

  1. Using actual viewing distance to calculate a 10 degree field of view in pixels AND G15: Ensuring that content does not violate the general flash threshold or red flash threshold

    Note: There is a tool that is available to carry out this test.

  2. G19: Ensuring that no component of the content flashes more than three times in any 1-second period

Advisory Techniques for 2.3.1

  • Reducing contrast for any flashing content (future link)

  • Avoiding fully saturated reds for any flashing content (future link)

  • Reducing the number of flashes even if they do not violate thresholds (future link)

  • Providing a mechanism to suppress any flashing content before it begins (future link)

2.3.2 Three Flashes: Content does not contain anything that flashes more than three times in any one second period. (Level AAA)Understanding Success Criterion 2.3.2

Sufficient Techniques for 2.3.2 (for the technologies you checked above)

  1. G19: Ensuring that no component of the content flashes more than three times in any 1-second period

Advisory Techniques for 2.3.2

  • Reducing contrast for any flashing content (future link)

  • Avoiding fully saturated reds for any flashing content (future link)

  • Reducing the number of flashes even if they don't violate thresholds (future link)

  1. Creating links to skip blocks of repeated material using one of the following techniques:

  2. Grouping blocks of repeated material in a way that can be skipped, using one of the following techniques:

  1. G88: Providing descriptive titles for Web pages AND associating a title with a Web page using one of the following techniques:

  1. G59: Placing the interactive elements in an order that follows sequences and relationships within the content

  2. Giving focus to elements in an order that follows sequences and relationships within the content using one of the following techniques:

  1. G91: Providing link text that describes the purpose of a link

  2. G53: Identifying the purpose of a link using link text combined with the text of the enclosing sentence

  3. Providing a supplemental description of the purpose of a link using one of the following techniques:

  4. Identifying the purpose of a link using link text combined with programmatically determined link context using one of the following techniques:

  1. Using two or more of the following techniques:

  1. G130: Providing descriptive headings

  2. G131: Providing descriptive labels

Note: Headings and labels must be programmatically determined, per success criterion 1.3.1.

  • Using unique section headings in a Web Page (future link)

  • Starting section headings with unique information (future link)

  1. G65: Providing a breadcrumb trail

  2. G63: Providing a site map

  3. G128: Indicating current location within navigation bars

  4. G127: Identifying a Web page's relationship to a larger collection of Web pages using one of the following techniques:

  • Providing a link to the home page or main page (future link)

  1. G91: Providing link text that describes the purpose of a link using one of the following techniques:

  2. Providing a supplemental description of the purpose of a link using one of the following techniques:

  1. G141: Organizing a page using headings

  2. H64: Using the title attribute of the frame element (HTML)

  • Using the 'live' property to mark live regions (future link) (ARIA)

Guideline 3.1: Make text content readable and understandable Understanding Guideline 3.1

3.1.1 Language of Page: The default human language of each Web page within the content can be programmatically determined. (Level A)Understanding Success Criterion 3.1.1

Sufficient Techniques for 3.1.1 (for the technologies you checked above)

  1. Identifying default human language(s) using one of the following techniques:

Advisory Techniques for 3.1.1

  • Specifying the default language in the HTTP header (future link)

  • using http or the Content-Language meta tag for metadata (future link)

3.1.2 Language of Parts: The human language of each passage or phrase in the content can be programmatically determined. (Level AA)Understanding Success Criterion 3.1.2

Note: This requirement does not apply to individual words. It also does not apply to proper names, to technical terms or to phrases that have become part of the language of the context in which they are used.

Sufficient Techniques for 3.1.2 (for the technologies you checked above)

  1. Identifying changes in human languages using one of the following techniques:

Advisory Techniques for 3.1.2

  • Making text that is not in the default human language of the Web page visually distinct (future link)

  • Giving the names of any languages used in foreign passages or phrases (future link)

  • Marking individual words, especially when they are links to versions in other languages (Deutsch, Français, Nederlands, Castellano, etc.) (future link)

3.1.3 Unusual Words: A mechanism is available for identifying specific definitions of words or phrases used in an unusual or restricted way, including idioms and jargon. (Level AAA)Understanding Success Criterion 3.1.3

Sufficient Techniques for 3.1.3 (for the technologies you checked above)
Situation A: If the word or phrase has a unique meaning within the Web page:

  1. G101: Providing the definition of a word or phrase used in an unusual or restricted way for the first occurrence of the word or phrase in a Web page using one of the following techniques:

  2. G101: Providing the definition of a word or phrase used in an unusual or restricted way for each occurrence of the word or phrase in a Web page using one of the following techniques:

Situation B: If the word or phrase means different things within the same Web page:

  1. G101: Providing the definition of a word or phrase used in an unusual or restricted way for each occurrence of the word or phrase in a Web page using one of the following techniques:

Advisory Techniques for 3.1.3

  • Using the title attribute to provide explanations of words or phrases (future link)

  • Using markup and visual formatting to help users recognize words that have special meaning (future link)

  • Providing a voice-enabled dictionary search so that users who have difficulty typing or spelling can speak the word whose definition they need (future link)

  • Providing a sign language dictionary to help users who are deaf find the necessary definitions (future link)

  • Providing a mechanism for finding definitions for all words in text content (future link)

  • Providing a mechanism to determine the meaning of each word or phrase in text content (future link)

  • Avoiding unusual foreign words (future link)

3.1.4 Abbreviations: A mechanism for finding the expanded form or meaning of abbreviations is available. (Level AAA)Understanding Success Criterion 3.1.4

Sufficient Techniques for 3.1.4 (for the technologies you checked above)
Situation A: If the abbreviation has only one meaning within the Web page:

  1. G102: Providing the expansion or explanation of an abbreviation for the first occurrence of the abbreviation in a Web page using one of the following techniques:

  2. G102: Providing the expansion or explanation of an abbreviation for all occurrences of the abbreviation in a Web page using one of the following techniques:

Situation B: If the abbreviation means different things within the same Web page:

  1. G102: Providing the expansion or explanation of an abbreviation for all occurrences of abbreviations in a Web page using one of the following techniques:

Advisory Techniques for 3.1.4

  • Using the title attribute to provide explanations of words or phrases (future link)

  • Using unique abbreviations in a Web page (future link)

  • Using visual formatting to help users recognize abbreviations (future link)

  • Providing access to a talking dictionary to support users who might have difficulty decoding written definitions (future link)

  • Providing a voice-enabled dictionary search so that users who have difficulty typing or spelling can speak the word whose definition they need (future link)

3.1.5 Reading Level: When text requires reading ability more advanced than the lower secondary education level, supplemental content or an alternate version is available that does not require reading ability more advanced than the lower secondary education level. (Level AAA)Understanding Success Criterion 3.1.5

Sufficient Techniques for 3.1.5 (for the technologies you checked above)

  1. G86: Providing a text summary that requires reading ability less advanced than the upper secondary education level

  2. G103: Providing visual illustrations of complex ideas, events, and processes

  3. G79: Providing a spoken version of the text

  4. Making the text easier to read (future link)

  5. Providing sign language versions of information, ideas, and processes that must be understood in order to use the content (future link)

Note: Different sites may address this success criterion in different ways. An audio version of the content may be helpful to some users. But if a site is intended for individuals who are deaf, providing an audio file would not be useful. For some people who are deaf, a sign language version of the page may be easier to understand than a written language version since sign language may be their first language. Some sites may decide to do both or other combinations. No technique will help all users who have difficulty. So different techniques are provided as sufficient techniques here for authors trying to make their sites more accessible. Any numbered technique or combination above can be used by a particular site and it is considered sufficient by the Working Group.

Advisory Techniques for 3.1.5

  • Providing text for navigational and landing pages that requires reading ability that is less advanced than the lower secondary education level (future link)

  • Providing text for interior pages that requires reading ability at the lower secondary education level (future link)

  • Including content summaries in metadata (future link)

  • Using the clearest and simplest language appropriate for the content (future link)

  • Using the Dublin Core accessibility element to associate text content with text, graphical, or spoken supplements (future link)

  • Using RDF to associate supplements with primary content (future link)

  • Providing a clear representational image on the site's home page (future link)

  • Making metadata viewable by humans (future link)

3.1.6 Pronunciation: A mechanism is available for identifying specific pronunciation of words where meaning is ambiguous without knowing the pronunciation. (Level AAA)Understanding Success Criterion 3.1.6

Sufficient Techniques for 3.1.6 (for the technologies you checked above)

  1. Providing the pronunciation immediately following the word (future link)

  2. Linking to pronunciations (future link)

  3. G62: Providing a glossary that includes pronunciation information for words that have a unique pronunciation in the content and have meaning that depends on pronunciation

  4. Providing pronunciation information using a technology-specific technique below

Advisory Techniques for 3.1.6

  • Providing pronunciations in a sound file, so that users can listen to the pronunciations of the word (future link)

  • Providing a mechanism for finding pronunciations for all foreign words in text content (future link)

  • Providing a mechanism to determine the pronunciations of each word or phrase in text content (future link)

Guideline 3.2: Make Web pages appear and operate in predictable ways Understanding Guideline 3.2

3.2.1 On Focus: When any component receives focus, it does not initiate a change of context. (Level A)Understanding Success Criterion 3.2.1

Sufficient Techniques for 3.2.1 (for the technologies you checked above)

  1. G107: Using "activate" rather than "focus" as a trigger for changes of context

Common Failures Identified by the Working Group for 3.2.1

3.2.2 On Input: Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component. (Level A)Understanding Success Criterion 3.2.2

Sufficient Techniques for 3.2.2 (for the technologies you checked above)

  1. G80: Providing a submit button to initiate a change of context using a technology-specific technique listed below

  2. G13: Describing what will happen before a change to a form control is made

    • H32: Providing submit buttons (HTML)

    • Using a button with a select element to perform an action (future link)

    • Hiding and showing content based on a select element change (future link)

    • Hiding and showing content based on a radio element change (future link)

Common Failures Identified by the Working Group for 3.2.2

3.2.3 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. (Level AA)Understanding Success Criterion 3.2.3

Sufficient Techniques for 3.2.3 (for the technologies you checked above)

  1. G61: Presenting repeated components in the same relative order each time they appear

Common Failures Identified by the Working Group for 3.2.3
Advisory Techniques for 3.2.3

  • Using templates to ensure consistency across multiple Web pages (future link)

  • Creating layout, positioning, layering, and alignment (future link)

3.2.4 Consistent Identification: Components that have the same functionality within a set of Web pages are identified consistently. (Level AA)Understanding Success Criterion 3.2.4

Sufficient Techniques for 3.2.4 (for the technologies you checked above)

  1. Using consistent labels, names, and text alternatives for content that has the same functionality.

Note 1: Text alternatives that are "consistent" are not always "identical." For instance, you may have an graphical arrow at the bottom of a Web page that links to the next Web page. The text alternative may say "Go to page 4." Naturally, it would not be appropriate to repeat this exact text alternative on the next Web page. It would be more appropriate to say "Go to page 5". Although these text alternatives would not be identical, they would be consistent, and therefore would satisfy this success criterion.

Note 2: A single non-text-content-item may be used to serve different functions. In such cases, different text alternatives are necessary and should be used. Examples can be commonly found with the use of icons such as check marks, cross marks, and traffic signs. Their functions can be different depending on the context of the Web page. A check mark icon may function as "approved", "completed", or "included", to name a few, depending on the situation. Using "check mark" as text alternative across all Web pages does not help users understand the function of the icon. Different text alternatives can be used when the same non-text content serves multiple functions.

Common Failures Identified by the Working Group for 3.2.4
Advisory Techniques for 3.2.4

  • Ensuring that the text alternative conveys the function of the component and what will happen when the user activates it (future link)

  • Using the same non-text content for a given function whenever possible (future link)

3.2.5 Change on Request: Changes of context are initiated only by user request. (Level AAA)Understanding Success Criterion 3.2.5

Sufficient Techniques for 3.2.5 (for the technologies you checked above)
Situation A: If the Web page allows automatic updates:

  1. G76: Providing a mechanism to request an update of the content instead of updating automatically

Situation B: If automatic redirects are possible:

  1. SVR1: Implementing automatic redirects on the server side instead of on the client side (SERVER)

  2. G110: Using an instant client-side redirect using one of the following techniques:

Situation C: If the Web page uses pop-up windows:

  1. Including pop-up windows using one of the following techniques:

Situation D: If using an onchange event on a select element:

  1. SCR19: Using an onchange event on a select element without causing a change of context (SCRIPT)

Common Failures Identified by the Working Group for 3.2.5
Advisory Techniques for 3.2.5

Opening new windows by:

  • Using the target attribute instead of scripts (future link), indicating that the link may open in a new window, or

  • Providing normal hyperlinks without the target attribute (future link), because many user agents allow users to open links in another window or tab.

Guideline 3.3: Help users avoid and correct mistakes that do occur Understanding Guideline 3.3

3.3.1 Error Identification: If an input error is automatically detected, the item that is in error is identified and described to the user in text. (Level A)Understanding Success Criterion 3.3.1

Sufficient Techniques for 3.3.1 (for the technologies you checked above)
Situation A: If a form contains fields for which information from the user is mandatory.

  1. G83: Providing text descriptions to identify required fields that were not completed

Situation B: If information provided by the user is required to be in a specific data format or of certain values.

  1. G85: Providing a text description when user input falls outside the required format or values

  2. SCR18: Providing client-side validation and alert (SCRIPT)

  3. Providing client-side validation and adding error text via the DOM (future link)

Advisory Techniques for 3.3.1

  • G139: Creating a mechanism that allows users to jump to errors

  • Validating form submissions on the server (future link)

  • Re-displaying a form with a summary of errors (future link)

  • Providing error notification as the user enters information (future link)

  • Assisting the user in making corrections by providing links to each error (future link)

  • Highlighting or visually emphasizing errors where they occur (future link)

  • Supplementing text with non-text content when reporting errors (future link)

3.3.2 Error Suggestion: If an input error is 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. (Level AA)Understanding Success Criterion 3.3.2

Sufficient Techniques for 3.3.2 (for the technologies you checked above)
Situation A: If a mandatory field contains no information:

  1. G83: Providing text descriptions to identify required fields that were not completed

Situation B: If information for a field is required to be in a specific data format:

  1. G85: Providing a text description when user input falls outside the required format or values

  2. Providing links to suggested correction text "close to" form fields, or providing the suggested correction text itself directly on the Web page "next to" form fields (future link)

  3. SCR18: Providing client-side validation and alert (SCRIPT)

  4. Providing client-side validation and adding error text via the DOM (future link)

Situation C: Information provided by the user is required to be one of a limited set of values:

  1. G84: Providing a text description when the user provides information that is not in the list of allowed values

  2. Providing links to suggested correction text "close to" form fields, or providing the suggested correction text itself directly on the Web page "next to" form fields (future link)

  3. SCR18: Providing client-side validation and alert (SCRIPT)

  4. Providing client-side validation and adding error text via the DOM (future link)

Advisory Techniques for 3.3.2

  • G139: Creating a mechanism that allows users to jump to errors

  • Making error messages easy to understand and distinguishable from other text in the Web page (future link)

  • Validating form submissions on the server (future link)

  • When mandatory information has not been provided, including descriptions or examples of correct information in addition to identifying the field as mandatory (future link)

  • Repeating and emphasizing suggestions for correcting each input error in the context of its form field (future link)

  • Providing a way for the user to skip from each item in a list of suggestions to its corresponding form field (future link)

  • Providing additional contextual help for the form field requiring change (future link)

Techniques for providing suggestions to the user (Advisory)

  • Providing a text description that contains information about the number of input errors, suggestions for corrections to each item, and instructions on how to proceed (future link)

  • Providing a text description that contains suggestions for correction as the first item (or one of the first items) of content, or emphasizing this information in the content (future link)

  • Displaying errors and suggestions in the context of the original form (for example, re-displaying a form where input errors and suggestions for correction are highlighted and displayed in the context of the original form) (future link)

HTML Techniques (Advisory)

  • Providing "correct examples" for data and data formats as initial text in mandatory form fields (future link)

  • Providing links to suggested correction text "close to" form fields, or providing the suggested correction text itself directly on the Web page "next to" form fields (future link)

Client-Side Scripting Techniques (Advisory)
ARIA Techniques (Advisory)

3.3.3 Error Prevention (Legal, Financial, Data): For forms that cause legal commitments or financial transactions to occur, that modify or delete user-controllable data in data storage systems, or that submit test responses, at least one of the following is true: (Level AA)Understanding Success Criterion 3.3.3

  1. Reversible: Transactions are reversible.

  2. Checked: Submitted data is checked for input errors before going on to the next step in the process.

  3. Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the transaction.

Sufficient Techniques for 3.3.3 (for the technologies you checked above)
Situation A: If an application causes a legal transaction to occur, such as making a purchase or submitting an income tax return:

  1. Providing a period of time after submission of the form when the order can be updated or canceled by the user (future link)

  2. G98: Providing the ability for the user to review and correct answers before submitting

Situation B: If an action causes information to be deleted:

  1. G99: Providing the ability to recover deleted information

  2. Providing a dialog to the user which requires confirmation before information is deleted (future link)

  3. Requiring a user to select a confirmation checkbox before submitting an action that causes information to be deleted (future link)

Situation C: If the Web page includes a testing application:

  1. G98: Providing the ability for the user to review and correct answers before submitting

  2. Asking for confirmation before final submission (future link)

Advisory Techniques for 3.3.3

  • Informing the user what irreversible action is about to happen (future link)

  • SCR18: Providing client-side validation and alert (SCRIPT)

  • Placing focus in the field containing the error (future link)

  • Avoiding use of the same words or letter combinations to begin each item of a drop-down list (future link)

3.3.4 Labels or Instructions: Labels or instructions are provided when content requires user input. (Level AA)Understanding Success Criterion 3.3.4

Sufficient Techniques for 3.3.4 (for the technologies you checked above)

  1. G131: Providing descriptive labels AND one of the following:

  2. H44: Using label elements to associate text labels with form controls (HTML)

  3. H65: Using the title attribute to identify form controls when the label element cannot be used (HTML)

  4. H71: Providing a description for groups of form controls using fieldset and legend elements (HTML)

Advisory Techniques for 3.3.4
Sufficient Techniques for 3.3.5 (for the technologies you checked above)
Situation A: If a form requires text input:

  1. G71: Providing a help link on every Web page

  2. Using scripts to provide context-sensitive bubble help (future link)

  3. Providing help by an assistant in the Web page (future link)

  4. Providing spell checking and suggestions for text input if applicable to the language (future link)

  5. Using the title attribute to provide context-sensitive help

  6. Providing instructions at the top of a form (future link)

Situation B: If a form requires text input in an expected data format:

  1. G89: Providing expected data format and example

  2. Providing instructions at the top of a form (future link)

Advisory Techniques for 3.3.5

  • Checking byte of character and auto-converting to expected byte for text input if applicable (future link)

3.3.6 Error Prevention (All): For forms that require the user to submit information, at least one of the following is true: (Level AAA)Understanding Success Criterion 3.3.6

  1. Reversible: Transactions are reversible.

  2. Checked: Submitted data is checked for input errors before going on to the next step in the process.

  3. Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the transaction.

Sufficient Techniques for 3.3.6 (for the technologies you checked above)

  1. Following the sufficient techniques for Success Criterion 3.3.3 for all forms that require the user to submit information.

Guideline 4.1: Maximize compatibility with current and future user agents, including assistive technologies Understanding Guideline 4.1

4.1.1 Parsing: Content implemented using markup languages has elements with complete start and end tags, except as allowed by their specifications, and are nested according to their specifications. (Level A)Understanding Success Criterion 4.1.1

Note: Start and end tags that are missing a critical character in their formation, such as a closing angle bracket or a mismatched attribute value quotation mark are not complete.

Sufficient Techniques for 4.1.1 (for the technologies you checked above)

  1. G134: Validating Web pages

  2. Fully conforming to specifications (future link)

  3. Ensuring that Web pages can be parsed by using one of the following techniques:

Common Failures Identified by the Working Group for 4.1.1

4.1.2 Name, Role, Value: For all user interface components, the name and role can be programmatically determined; states, properties, and values that can be set by the user can be programmatically determined and programmatically set; and notification of changes to these items is available to user agents, including assistive technologies. (Level A)Understanding Success Criterion 4.1.2

Note: This success criterion is primarily for Web authors who develop or script their own user interface controls. For example, standard HTML controls already meet this provision when used according to specification.

Sufficient Techniques for 4.1.2 (for the technologies you checked above)
Situation A: If using a standard user interface component in a markup language (e.g. HTML):

  1. G108: Using markup features to expose the name and role, allow user-settable properties to be directly set, and provide notification of changes using technology-specific techniques below:

Situation B: If using script or code to re-purpose a standard user interface component in a markup language:

  1. Exposing the names and roles, allowing user-settable properties to be directly set, and providing notification of changes using one of the following techniques:

Situation C: If using a standard user interface component in a programming technology:

  1. G135: Using the accessibility API features of a technology to expose names and roles, to allow user-settable properties to be directly set, and to provide notification of changes

Situation D: If creating your own user interface component in a programming language:

  1. G10: Creating components using a technology that supports the accessibility API features of the platforms on which the user agents will be run to expose the names and roles, allow user-settable properties to be directly set, and provide notification of changes

Common Failures Identified by the Working Group for 4.1.2
Advisory Techniques for 4.1.2

  • Providing labels for all form controls that do not have implicit labels (future link)

Conformance Requirements

In order to conform to WCAG 2.0 all of the following conformance requirements must be met for each Web page:

1.) Level A Conformance: For level A conformance (the minimum level of conformance), the Web page satisfies all the Level A success criteria, or the page satisfies conformance requirement 4.

2.) Level AA Conformance: For level AA conformance, the Web page satisfies all the Level A and Level AA success criteria, or the page satisfies conformance requirement 4.

3.) Level AAA Conformance: For level AAA conformance, the Web page satisfies all the Level A, Level AA and Level AAA success criteria, or the page satisfies conformance requirement 4.

4.) Alternate Versions: If the Web page does not meet all of the success criteria for a specified level, then a mechanism to obtain an alternate version that meets all of the success criteria can be derived from the nonconforming content or its URI, and that mechanism meets all success criteria for the specified level of conformance. The alternate version does not need to be matched page for page with the original (e.g. the alternative to a page may consist of multiple pages). If multiple language versions are available, then conforming versions are required for each language offered.

Editorial Note: As currently worded, requirement #4 ensures that a mechanism is available to find a conforming version from any nonconforming version. The working group is concerned that it has not identified enough supported mechanisms to meet the needs and constraints of different technologies or the limitations authors may have in their content or server. Requirement #4 is therefore "at risk" in its current form. If there are not sufficient techniques to meet the current language, it would have to change. The two options under consideration if that happens both have disadvantages. The options are:

  • Fallback option #1: Requiring an accessible link from the nonconforming content, which would block use of some current and future technologies if they do not support WCAG conforming links, or

  • Fallback option #2: Allowing the requirement to be met by a single page with links to the conforming and non-conforming pages, or other techniques that may provide an option to find the conforming version when browsing, but that would leave the user with no way to find the conforming page after reaching a non-conforming page via search, or a link from a blog, email, article, other page etc.

Further discussion of this topic is available at Alternate Versions Conformance Requirement. The working group seeks suggestions for additional sufficient techniques that would allow us to keep the current language as well as comments, input, and thoughts on the two alternatives should we fail to identify enough.

5.) Accessibility-Supported Technologies Only: Only documented accessibility-supported Web technologies are relied upon to meet success criteria. Any information or functionality that is implemented in technologies that are not accessibility supported must also be available via technologies that are accessibility supported.

6.) Non-Interference: If Web technologies that are not accessibility supported are used on a page, or accessibility-supported technologies are used in a non-conforming way, then they do not block the ability of the users to access the rest of the page. Specifically:

  1. No Keyboard Trap: If focus can be moved to technologies that are not accessibility supported using a keyboard interface, then focus can be moved away from that content using only a keyboard interface, and the method for doing so is described before the content is encountered and in a way that meets all Level A success criteria.

  2. Three Flashes or Below Threshold: To minimize the risk of seizures due to photosensitivity, content does 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 (see Success Criterion 2.3.1).

  3. Non support: The content continues to meet the conformance requirements when the (non accessibility-supported) technology is turned on, turned off, or is not supported by a user agent.

7.) Full pages: Conformance is for full Web page(s) only, and cannot be achieved if part of a Web page is excluded.

8.) Supplemental Information: For the purpose of determining conformance, a conforming alternative to part of a page's content is considered part of the page.

9.) Complete processes: If a Web page that is part of a process does not conform at some level, then no conformance claim is made at that level for any Web pages in that process.

Example: An online store has a series of pages that are used to select and purchase products. All pages in the series from start to finish (checkout) must conform in order to claim conformance for any page that is part of the sequence.

For more information, see Understanding Conformance Requirements.