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How to Meet WCAG 2.0

A customizable quick reference to Web Content Accessibility Guidelines 2.0 requirements (success criteria) and techniques

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Introduction

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This web page can be used as a checklist for WCAG 2.0. It provides:

  • All of the requirements (called "success criteria") from Web Content Accessibility Guidelines (WCAG) 2.0
  • Techniques to meet the requirements, which are linked to pages with descriptions, code examples, browser and assistive technology support notes, and tests.
  • Failures to avoid, which are linked to pages with descriptions, examples, and tests.
  • "Understanding" links to pages that explain the intent of the guideline or success criterion, how it helps people with different disabilities, key terms, and resources.

You can customize what is included in this page by selecting from the Customize this Quick Reference section which Technologies, Levels of success criteria, and Sections of techniques you want to include.

For an introduction to WCAG, Techniques, and Understanding documents, see the WCAG Overview.

Note that even content that conforms at the highest level (AAA) will not be accessible to individuals with all types, degrees, or combinations of disability, particularly in the cognitive language and learning areas. Authors are encouraged to seek relevant advice about current best practice to ensure that Web content is accessible, as far as possible, to this community.

About the Techniques

For important information about the techniques, please see the Understanding Techniques for WCAG Success Criteria section of Understanding WCAG 2.0.

Note: The basis for determining conformance to WCAG 2.0 is the success criteria, not the techniques. (The success criteria have 3-level numbering (0.0.0) and in this page they are followed by a link "Understanding Success Criterion".) All techniques are informative; that means they are not required. There may be other techniques besides the ones listed here.

New Techniques and Comments

The Techniques for WCAG 2.0 document is updated periodically, and anyone can submit techniques that will be considered for inclusion in an update. Please submit corrections, updates, or new information related to techniques, failures, or other WCAG documentation to the WCAG Working Group, per the instructions for commenting.

Table of Contents

WCAG 2.0 Quick Reference List

This Quick Reference is currently customized to include:

Text Alternatives:

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

Advisory Techniques for Guideline 1.1

Non-text Content:

1.1.1 All non-text content that is presented to the user has a text alternative that serves the equivalent purpose, 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. (Refer to Guideline 4.1 for additional requirements for controls and content that accepts user input.)

  • Time-Based Media: If non-text content is time-based media, then text alternatives at least provide descriptive identification of the non-text content. (Refer to Guideline 1.2 for additional requirements for media.)

  • Test: If non-text content is a test or exercise that would be invalid if presented in text, then text alternatives at least provide descriptive identification of the non-text content.

  • Sensory: If non-text content is primarily intended to create a specific sensory experience, then text alternatives at least provide descriptive identification of the non-text content.

  • 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 of CAPTCHA using output modes for different types of sensory perception are provided to accommodate different disabilities.

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

Sufficient Techniques for 1.1.1 - Non-text Content

Note: Other techniques may also be sufficient if they meet the success criterion.

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 one of the following Short text alternative techniques for Situation A:

Short text alternative techniques for Situation A:

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 one of the following Short text alternative techniques for Situation B AND one of the following Long text alternative techniques for Situation B:

Short text alternative techniques for Situation B:

Long text alternative techniques for Situation B:

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 one of the following Text alternative techniques for controls and input for Situation C:

Text alternative techniques for controls and input for Situation C:

Situation D: If non-text content is time-based media (including live video-only and live audio-only); a test or exercise that would be invalid if presented in text; or primarily intended to create a specific sensory experience:
  1. Providing a descriptive label using one of the following Short text alternative techniques for Situation D:

  2. ARIA6: Using aria-label to provide labels for objects (ARIA)

  3. ARIA10: Using aria-labelledby to provide a text alternative for non-text content (ARIA)

  4. G68: Providing a short text alternative that describes the purpose of live audio-only and live video-only content using one of the following Short text alternative techniques for Situation D:

  5. G100: Providing a short text alternative which is the accepted name or a descriptive name of the non-text content using one of the following Short text alternative techniques for Situation D:

Short text alternative techniques for Situation D:

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 following Techniques to indicate that text alternatives are not required for Situation F:

Techniques to indicate that text alternatives are not required for Situation F:

Advisory Techniques for 1.1.1 - Non-text Content
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)

  • Providing different sizes for non-text content when it cannot have an equivalent accessible alternative (future link)

  • Using server-side scripts to resize images of text (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)

General techniques to minimize the barrier of CAPTCHAs
  • Providing more than two modalities of CAPTCHAs (future link)

  • Providing access to a human customer service representative who can bypass CAPTCHA (future link)

  • Not requiring CAPTCHAs for authorized users (future link)

HTML Techniques (Advisory)
CSS Techniques (Advisory)
WAI-ARIA Techniques (Advisory)
  • Using the ARIA presentation role to indicate elements are purely presentational (future link)

Silverlight Techniques (Advisory)
Metadata Techniques (Advisory)
  • Using metadata to associate text transcriptions with a video (future link)

  • Using metadata to associate text transcriptions with audio-only content (future link)

    • EXAMPLE: Providing, in metadata, URI(s) that points to an audio description and a text transcript of a video.

    • EXAMPLE: Providing, in metadata, URI(s) that point to several text transcripts (English, French, Dutch) of an audio file.

Time-based Media:

Guideline 1.2 Provide alternatives for time-based media.Understanding Guideline 1.2

Audio-only and Video-only (Prerecorded):

1.2.1 For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such: (Level A)Understanding Success Criterion 1.2.1

  • Prerecorded Audio-only: An alternative for time-based media is provided that presents equivalent information for prerecorded audio-only content.

  • Prerecorded Video-only: Either an alternative for time-based media or an audio track is provided that presents equivalent information for prerecorded video-only content.

Advisory Techniques for 1.2.1 - Audio-only and Video-only (Prerecorded)
  • Providing a transcript of a live audio only presentation after the fact (future link)

  • 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)

Captions (Prerecorded):

1.2.2 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. (Level A)Understanding Success Criterion 1.2.2

Advisory Techniques for 1.2.2 - Captions (Prerecorded)
  • Providing a note saying "No sound is used in this clip" for video-only clips (future link)

  • Using SMIL 1.0 to provide captions for all languages for which there are audio tracks (future link)

  • Using SMIL 2.0 to provide captions for all languages for which there are audio tracks (future link)

Audio Description or Media Alternative (Prerecorded):

1.2.3 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. (Level A)Understanding Success Criterion 1.2.3

Sufficient Techniques for 1.2.3 - Audio Description or Media Alternative (Prerecorded)

Note: Other techniques may also be sufficient if they meet the success criterion.

  1. G69: Providing an alternative for time based media using one of the following techniques

  2. Linking to the alternative for time-based media using one of the following techniques

  3. G78: Providing a second, user-selectable, audio track that includes audio descriptions

  4. G78: Providing a second, user-selectable, audio track that includes audio descriptions AND SL1: Accessing Alternate Audio Tracks in Silverlight Media (Silverlight)

  5. G173: Providing a version of a movie with audio descriptions using one of the following:

  6. G8: Providing a movie with extended audio descriptions using one of the following:

  7. G203: Using a static text alternative to describe a talking head video

Advisory Techniques for 1.2.3 - Audio Description or Media Alternative (Prerecorded)
  • Providing audio description in multiple languages in SMIL 1.0 (future link)

  • Providing audio description in multiple languages in SMIL 2.0 (future link)

Captions (Live):

1.2.4 Captions are provided for all live audio content in synchronized media. (Level AA)Understanding Success Criterion 1.2.4

Audio Description (Prerecorded):

1.2.5 Audio description is provided for all prerecorded video content in synchronized media. (Level AA)Understanding Success Criterion 1.2.5

Advisory Techniques for 1.2.5 - Audio Description (Prerecorded)
  • Providing audio description in multiple languages in SMIL 1.0 (future link)

  • Providing audio description in multiple languages in SMIL 2.0 (future link)

  • Providing audio description for live synchronized media (future link)

Sign Language (Prerecorded):

1.2.6 Sign language interpretation is provided for all prerecorded audio content in synchronized media. (Level AAA)Understanding Success Criterion 1.2.6

Advisory Techniques for 1.2.6 - Sign Language (Prerecorded)
Metadata Techniques
  • Using metadata to associate sign language alternatives of a video to enable choice of sign language (future link)

    • EXAMPLE: Providing, in metadata, URI(s) that point to several English sign language translations (ASL, SASL, BSL, Auslan, ISL, NZSL) of a Web page.

Extended Audio Description (Prerecorded):

1.2.7 Where pauses in foreground audio are insufficient to allow audio descriptions to convey the sense of the video, extended audio description is provided for all prerecorded video content in synchronized media. (Level AAA)Understanding Success Criterion 1.2.7

Sufficient Techniques for 1.2.7 - Extended Audio Description (Prerecorded)

Note: Other techniques may also be sufficient if they meet the success criterion.

  1. G8: Providing a movie with extended audio descriptions using one of the following:

Advisory Techniques for 1.2.7 - Extended Audio Description (Prerecorded)
  • Adding extended audio description in multiple languages in SMIL 1.0 (future link)

  • Adding extended audio description in multiple languages in SMIL 2.0 (future link)

Media Alternative (Prerecorded):

1.2.8 An alternative for time-based media is provided for all prerecorded synchronized media and for all prerecorded video-only media. (Level AAA)Understanding Success Criterion 1.2.8

Sufficient Techniques for 1.2.8 - Media Alternative (Prerecorded)

Note: Other techniques may also be sufficient if they meet the success criterion.

Situation A: If the content is prerecorded synchronized media:
  1. G69: Providing an alternative for time based media using one of the following techniques

  2. Linking to the alternative for time-based media using one of the following techniques

Situation B: If the content is prerecorded video-only:
  1. G159: Providing an alternative for time-based media for video-only content

Advisory Techniques for 1.2.8 - Media Alternative (Prerecorded)

Audio-only (Live):

1.2.9 An alternative for time-based media that presents equivalent information for live audio-only content is provided. (Level AAA)Understanding Success Criterion 1.2.9

Advisory Techniques for 1.2.9 - Audio-only (Live)
  • Using metadata to associate text transcriptions with audio-only content (future link)

    Example: Providing, in metadata, URI(s) that point to several text transcripts (English, French, Dutch) of an audio file.

Adaptable:

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

Info and Relationships:

1.3.1 Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text. (Level A)Understanding Success Criterion 1.3.1

Sufficient Techniques for 1.3.1 - Info and Relationships

Note: Other techniques may also be sufficient if they meet the success criterion.

Situation A: The technology provides semantic structure to make information and relationships conveyed through presentation programmatically determinable:
  1. ARIA11: Using ARIA landmarks to identify regions of a page (ARIA)

  2. ARIA12: Using role=heading to identify headings (ARIA)

  3. ARIA13: Using aria-labelledby to name regions and landmarks (ARIA)

  4. ARIA16: Using aria-labelledby to provide a name for user interface controls (ARIA)

  5. ARIA17: Using grouping roles to identify related form controls (ARIA)

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

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

  8. G140: Separating information and structure from presentation to enable different presentations

  9. 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. FLASH8: Adding a group name to the accessible name of a form control (Flash)

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

Advisory Techniques for 1.3.1 - Info and Relationships
Failures for SC 1.3.1 - Info and Relationships

Meaningful Sequence:

1.3.2 When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined. (Level A)Understanding Success Criterion 1.3.2

Advisory Techniques for 1.3.2 - Meaningful Sequence
  • 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)

  • Providing a link to linearized rendering (future link)

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

Sensory Characteristics:

1.3.3 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. (Level A)Understanding Success Criterion 1.3.3

Note: For requirements related to color, refer to Guideline 1.4.

Advisory Techniques for 1.3.3 - Sensory Characteristics
  • 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)

Distinguishable:

Guideline 1.4 Make it easier for users to see and hear content including separating foreground from background. Understanding Guideline 1.4

Advisory Techniques for Guideline 1.4

Use of Color:

1.4.1 Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. (Level A)Understanding Success Criterion 1.4.1

Note: This success criterion addresses color perception specifically. Other forms of perception are covered in Guideline 1.3 including programmatic access to color and other visual presentation coding.

Advisory Techniques for 1.4.1 - Use of Color

Audio Control:

1.4.2 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. (Level A)Understanding Success Criterion 1.4.2

Note: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether or not it is used to meet other success criteria) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

Advisory Techniques for 1.4.2 - Audio Control
  • Providing a site-wide 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)

Contrast (Minimum):

1.4.3 The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following: (Level AA)Understanding Success Criterion 1.4.3

  • Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 3:1;

  • Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.

  • Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.

Advisory Techniques for 1.4.3 - Contrast (Minimum)
  • G156: Using a technology that has commonly-available user agents that can change the foreground and background of blocks of text

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

  • Using greater contrast level for red-black text/background combinations (future link)

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

  • Using a light pastel background rather than a white background behind black text to create sufficient but not extreme contrast (future link)

  • Making icons using simple line drawings that meet the contrast provisions for text (future link)

  • Providing sufficient color contrast in graphs and charts (future link)

  • Using a 3:1 contrast ratio or higher as the default presentation (future link)

  • Providing sufficient color contrast for empty text fields (future link)

Resize text:

1.4.4 Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality. (Level AA)Understanding Success Criterion 1.4.4

Advisory Techniques for 1.4.4 - Resize text

Images of Text:

1.4.5 If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text except for the following: (Level AA)Understanding Success Criterion 1.4.5

  • Customizable: The image of text can be visually customized to the user's requirements;

  • Essential: A particular presentation of text is essential to the information being conveyed.

Note: Logotypes (text that is part of a logo or brand name) are considered essential.

Advisory Techniques for 1.4.5 - Images of Text
General techniques for non-text content
  1. Identifying informative non-text content (future link)

CSS Techniques
  1. C12: Using percent for font sizes (CSS)

  2. C13: Using named font sizes (CSS)

  3. C14: Using em units for font sizes (CSS)

  4. C8: Using CSS letter-spacing to control spacing within a word (CSS)

  5. C6: Positioning content based on structural markup (CSS)

  6. Avoid applying text styling to text characters within a word (future link)

Contrast (Enhanced):

1.4.6 The visual presentation of text and images of text has a contrast ratio of at least 7:1, except for the following: (Level AAA)Understanding Success Criterion 1.4.6

  • Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 4.5:1;

  • Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.

  • Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.

Advisory Techniques for 1.4.6 - Contrast (Enhanced)
  • G156: Using a technology that has commonly-available user agents that can change the foreground and background of blocks of text

  • 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 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

  • Using a light pastel background rather than a white background behind black text to create sufficient but not extreme contrast (future link)

  • Making icons using simple line drawings that meet the contrast provisions for text (future link)

  • Providing sufficient color contrast in graphs and charts (future link)

  • Using a 3:1 contrast ratio or higher as the default presentation (future link)

  • Providing sufficient color contrast for empty text fields (future link)

Low or No Background Audio:

1.4.7 For prerecorded audio-only content that (1) contains primarily speech in the foreground, (2) is not an audio CAPTCHA or audio logo, and (3) is not vocalization intended to be primarily musical expression such as singing or rapping, at least one of the following is true: (Level AAA)Understanding Success Criterion 1.4.7

  • No Background: The audio does not contain background sounds.

  • Turn Off: The background sounds can be turned off.

  • 20 dB: The background sounds are at least 20 decibels lower than the foreground speech content, with the exception of occasional sounds that last for only one or two seconds.

    Note: Per the definition of "decibel," background sound that meets this requirement will be approximately four times quieter than the foreground speech content.

Advisory Techniques for 1.4.7 - Low or No Background Audio
  • Providing a way for users to adjust auditory levels of foreground and background sound independently (future link)

  • Providing an audio track for synchronized media that includes background sounds that are at least 20 decibels lower than speech (future link)

Visual Presentation:

1.4.8 For the visual presentation of blocks of text, a mechanism is available to achieve the following: (Level AAA)Understanding Success Criterion 1.4.8

  1. Foreground and background colors can be selected by the user.

  2. Width is no more than 80 characters or glyphs (40 if CJK).

  3. Text is not justified (aligned to both the left and the right margins).

  4. Line spacing (leading) is at least space-and-a-half within paragraphs, and paragraph spacing is at least 1.5 times larger than the line spacing.

  5. Text can be resized without assistive technology up to 200 percent in a way that does not require the user to scroll horizontally to read a line of text on a full-screen window.

Sufficient Techniques for 1.4.8 - Visual Presentation

Note: Other techniques may also be sufficient if they meet the success criterion.

Instructions: Since this is a multi-part success criterion, you must satisfy one of the numbered items for each of the requirements below.

First Requirement: Techniques to ensure foreground and background colors can be selected by the user
  1. C23: Specifying text and background colors of secondary content such as banners, features and navigation in CSS while not specifying text and background colors of the main content (CSS) OR

  2. C25: Specifying borders and layout in CSS to delineate areas of a Web page while not specifying text and text-background colors (CSS) OR

  3. G156: Using a technology that has commonly-available user agents that can change the foreground and background of blocks of text OR

  4. G148: Not specifying background color, not specifying text color, and not using technology features that change those defaults OR

  5. G175: Providing a multi color selection tool on the page for foreground and background colors

Second Requirement: Techniques to ensure width is no more than 80 characters or glyphs (40 if CJK)
  1. H87: Not interfering with the user agent's reflow of text as the viewing window is narrowed (HTML) OR

  2. C20: Using relative measurements to set column widths so that lines can average 80 characters or less when the browser is resized (CSS)

Third Requirement: Techniques to ensure text is not justified (aligned to both the left and the right margins)
  1. C19: Specifying alignment either to the left OR right in CSS (CSS) OR

  2. G172: Providing a mechanism to remove full justification of text OR

  3. G169: Aligning text on only one side

Fourth Requirement: Techniques to ensure line spacing (leading) is at least space-and-a-half within paragraphs, and paragraph spacing is at least 1.5 times larger than the line spacing
  1. G188: Providing a button on the page to increase line spaces and paragraph spaces OR

  2. C21: Specifying line spacing in CSS (CSS)

Fifth Requirement: Techniques to ensure text can be resized without assistive technology up to 200 percent in a way that does not require the user to scroll horizontally to read a line of text on a full-screen window
  1. Not interfering with the user agent's reflow of text as the viewing window is narrowed (General, Future Link) OR

  2. G146: Using liquid layout AND using measurements that are relative to other measurements in the content by using one or more of the following techniques:

  3. C26: Providing options within the content to switch to a layout that does not require the user to scroll horizontally to read a line of text (CSS)

Advisory Techniques for 1.4.8 - Visual Presentation
  • Using a hover effect to highlight a paragraph, list items, or table cells (CSS) (future link)

  • Presenting text in sans serif font or providing a mechanism to achieve this (CSS) (future link)

  • Using vertical (bulleted or numbered) lists rather than inline lists (future link)

  • Using upper and lower case according to the spelling conventions of the text language (future link)

  • Providing large fonts by default (future link)

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

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

  • Providing sufficient inter-column spacing (future link)

  • Avoiding centrally aligned text (future link)

  • Avoiding chunks of italic text (future link)

  • Avoiding overuse of different styles on individual pages and in sites (future link)

  • Making links visually distinct (future link)

  • Providing expandable bullets (future link)

  • Show/hide bullet points (future link)

  • Putting an em-space or two spaces after sentences (future link)

Images of Text (No Exception):

1.4.9 Images of text are only used for pure decoration or where a particular presentation of text is essential to the information being conveyed. (Level AAA)Understanding Success Criterion 1.4.9

Note: Logotypes (text that is part of a logo or brand name) are considered essential.

Advisory Techniques for 1.4.9 - Images of Text (No Exception)
General Techniques for Non-Decorative Content
  • Using server-side scripts to resize images of text (future link)

CSS Techniques

Keyboard Accessible:

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

Keyboard:

2.1.1 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 - Keyboard

Note: Other techniques may also be sufficient if they meet the success criterion.

  1. G202: Ensuring keyboard control for all functionality

  2. Ensuring keyboard control by using one of the following techniques.

  3. G90: Providing keyboard-triggered event handlers using one of the following techniques:

  4. FLASH17: Providing keyboard access to a Flash object and avoiding a keyboard trap (Flash) AND using the following techniques as applicable:

Advisory Techniques for 2.1.1 - Keyboard
  • Using XHTML role, state, and value attributes if repurposing static elements as interactive user interface components (future link) AND SCR29: Adding keyboard-accessible actions to static HTML elements (Scripting)

  • Providing keyboard shortcuts 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) (Scripting)

  • Using the onactivate event (future link) (Scripting)

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

No Keyboard Trap:

2.1.2 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. (Level A)Understanding Success Criterion 2.1.2

Note: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

Keyboard (No Exception):

2.1.3 All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes. (Level AAA)Understanding Success Criterion 2.1.3

Sufficient Techniques for 2.1.3 - Keyboard (No Exception)

Note: Other techniques may also be sufficient if they meet the success criterion.

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 path-dependent input, then it is not possible to meet this Level AAA Success Criterion.

Enough Time:

Guideline 2.2 Provide users enough time to read and use content. Understanding Guideline 2.2

Timing Adjustable:

2.2.1 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, "press the space bar"), 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 essential and extending it would invalidate the activity; or

  • 20 Hour Exception: The time limit is longer than 20 hours.

Note: This success criterion helps ensure that users can complete tasks without unexpected changes in content or context that are a result of a time limit. This success criterion should be considered in conjunction with Success Criterion 3.2.1, which puts limits on changes of content or context as a result of user action.

Advisory Techniques for 2.2.1 - Timing Adjustable
  • Using a script to poll the server and notify a user if a time limit is present (future link) (Scripting)

  • Using sounds to focus user's attention (future link)

Pause, Stop, Hide:

2.2.2 For moving, blinking, scrolling, or auto-updating information, all of the following are true: (Level A)Understanding Success Criterion 2.2.2

  • 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; and

  • 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.

Note 1: For requirements related to flickering or flashing content, refer to Guideline 2.3.

Note 2: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

Note 3: Content that is updated periodically by software or that is streamed to the user agent is not required to preserve or present information that is generated or received between the initiation of the pause and resuming presentation, as this may not be technically possible, and in many situations could be misleading to do so.

Note 4: An animation that occurs as part of a preload phase or similar situation can be considered essential if interaction cannot occur during that phase for all users and if not indicating progress could confuse users or cause them to think that content was frozen or broken.

Advisory Techniques for 2.2.2 - Pause, Stop, Hide
  • 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 5 seconds (future link)

No Timing:

2.2.3 Timing is not an essential part of the event or activity presented by the content, except for non-interactive synchronized media and real-time events. (Level AAA)Understanding Success Criterion 2.2.3

Interruptions:

2.2.4 Interruptions can be postponed or suppressed by the user, except interruptions involving an emergency. (Level AAA)Understanding Success Criterion 2.2.4

Re-authenticating:

2.2.5 When an authenticated session expires, the user can continue the activity without loss of data after re-authenticating. (Level AAA)Understanding Success Criterion 2.2.5

Sufficient Techniques for 2.2.5 - Re-authenticating

Note: Other techniques may also be sufficient if they meet the success criterion.

  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.

Seizures:

Guideline 2.3 Do not design content in a way that is known to cause seizures.Understanding Guideline 2.3

Advisory Techniques for Guideline 2.3

Three Flashes or Below Threshold:

2.3.1 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. (Level A)Understanding Success Criterion 2.3.1

Note: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

Advisory Techniques for 2.3.1 - Three Flashes or Below Threshold
  • 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)

  • Slowing down live material to avoid rapid flashes (as in flashbulbs) (future link)

  • Freezing the image momentarily if 3 flashes within one second are detected (future link)

  • Dropping the contrast ratio if 3 flashes within one second are detected (future link)

  • Allowing users to set a custom flash rate limit (future link)

Three Flashes:

2.3.2 Web pages do not contain anything that flashes more than three times in any one second period. (Level AAA)Understanding Success Criterion 2.3.2

Advisory Techniques for 2.3.2 - Three Flashes
  • 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)

  • Slowing down live material to avoid rapid flashes (as in flashbulbs) (future link)

  • Freezing the image momentarily if 3 flashes within one second are detected (future link)

  • Dropping the contrast ratio if 3 flashes within one second are detected (future link)

Guideline 2.4 Provide ways to help users navigate, find content, and determine where they are. Understanding Guideline 2.4

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

  • Providing skip links to enhance page navigation (future link)

  • Providing access keys (future link)

  • Using accessibility supported technologies which allow structured navigation by user agents and assistive technologies (future link)

  • C6: Positioning content based on structural markup (CSS)

  • Providing a highly visible highlighting mechanism for links or controls when they receive keyboard focus (future link)

  • Creating alternative presentation orders (future link)

Note: Other techniques may also be sufficient if they meet the success criterion.

  1. ARIA1: Using the aria-describedby property to provide a descriptive label for user interface controls (ARIA)

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

  3. H30: Providing link text that describes the purpose of a link for anchor elements (HTML)

  4. H24: Providing text alternatives for the area elements of image maps (HTML)

  5. FLASH27: Providing button labels that describe the purpose of a button (Flash)

  6. Allowing the user to choose short or long link text using one of the techniques below:

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

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

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

  10. G91: Providing link text that describes the purpose of a link AND Semantically indicating links using one of the following techniques:

Note: Other techniques may also be sufficient if they meet the success criterion.

  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)

  • Highlighting a link or control when the mouse hovers over it (future link)

  • Providing a highly visible highlighting mechanism for links or controls when they receive keyboard focus (future link)

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

  • Providing mechanisms to navigate to different sections of the content of a Web page (future link)

Readable:

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

Advisory Techniques for Guideline 3.1

Advisory Techniques for 3.1.1 - Language of Page

Language of Parts:

3.1.2 The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, and words or phrases that have become part of the vernacular of the immediately surrounding text. (Level AA)Understanding Success Criterion 3.1.2

Advisory Techniques for 3.1.2 - Language of Parts

Unusual Words:

3.1.3 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 - Unusual Words

Note: Other techniques may also be sufficient if they meet the success criterion.

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 - Unusual Words
  • 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)

  • Using a series of dictionaries in cascading fashion to provide meanings (future link)

Abbreviations:

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

Sufficient Techniques for 3.1.4 - Abbreviations

Note: Other techniques may also be sufficient if they meet the success criterion.

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 - Abbreviations
  • 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)

Reading Level:

3.1.5 When text requires reading ability more advanced than the lower secondary education level after removal of proper names and titles, supplemental content, or a version that does not require reading ability more advanced than the lower secondary education level, is available. (Level AAA)Understanding Success Criterion 3.1.5

Sufficient Techniques for 3.1.5 - Reading Level

Note: Other techniques may also be sufficient if they meet the success criterion.

  1. G86: Providing a text summary that can be understood by people with lower secondary education level reading ability

  2. G103: Providing visual illustrations, pictures, and symbols to help explain ideas, events, and processes

  3. G79: Providing a spoken version of the text

  4. G153: Making the text easier to read

  5. G160: Providing sign language versions of information, ideas, and processes that must be understood in order to use the content

Note: Different sites may address this Success Criterion in different ways. An audio version of the content may be helpful to some users. 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 - Reading Level
  • 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 RDF to associate supplements with primary content (future link)

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

  • Clearly marking, by use of text or icon, content which has been optimized for easy reading (future link)

  • Using sentences that contain no redundant words, that is, words that do not change the meaning of the sentence (future link)

  • Using sentences that contain no more than two conjunctions (future link)

  • Using sentences that are no longer than the typical accepted length for secondary education (Note: In English that is 25 words) (future link)

  • Using sentences that do not contain complex words or phrases that could be replaced with more commonly used words without changing the meaning of the sentence (future link)

  • Providing summaries for different sections of text (future link)

  • Using metadata to associate alternatives at different reading levels. (future link)

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

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

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

  • Making metadata viewable by humans (future link)

    • EXAMPLE: Providing, in metadata, URI(s) that point to a pre-primary-reading-level and a primary-reading-level text transcript of a new scientific discovery advanced-reading-level article.

  • Providing progressive complexity for site and page content (future link)

Pronunciation:

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

Sufficient Techniques for 3.1.6 - Pronunciation

Note: Other techniques may also be sufficient if they meet the success criterion.

  1. G120: Providing the pronunciation immediately following the word

  2. G121: Linking to pronunciations

  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. G163: Using standard diacritical marks that can be turned off

  5. H62: Using the ruby element (HTML) (XHTML 1.1)

Advisory Techniques for 3.1.6 - Pronunciation
  • 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)

Predictable:

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

Advisory Techniques for Guideline 3.2

On Focus:

3.2.1 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 - On Focus

Note: Other techniques may also be sufficient if they meet the success criterion.

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

Note: A change of content is not always a change of context. This success criterion is automatically met if changes in content are not also changes of context.

Advisory Techniques for 3.2.1 - On Focus

On Input:

3.2.2 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

Advisory Techniques for 3.2.2 - On Input

Consistent Navigation:

3.2.3 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

Advisory Techniques for 3.2.3 - Consistent Navigation

Consistent Identification:

3.2.4 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 - Consistent Identification

Note: Other techniques may also be sufficient if they meet the success criterion.

  1. G197: Using labels, names, and text alternatives consistently for content that has the same functionality AND following the sufficient techniques for Success Criterion 1.1.1 and sufficient techniques for Success Criterion 4.1.2 for providing labels, names, and text alternatives.

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.

Advisory Techniques for 3.2.4 - Consistent Identification
  • 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)

Change on Request:

3.2.5 Changes of context are initiated only by user request or a mechanism is available to turn off such changes. (Level AAA)Understanding Success Criterion 3.2.5

Sufficient Techniques for 3.2.5 - Change on Request

Note: Other techniques may also be sufficient if they meet the success criterion.

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 (Scripting)

Advisory Techniques for 3.2.5 - Change on Request

Input Assistance:

Guideline 3.3 Help users avoid and correct mistakes. Understanding Guideline 3.3

Advisory Techniques for Guideline 3.3

Error Identification:

3.3.1 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. (Level A)Understanding Success Criterion 3.3.1

Advisory Techniques for 3.3.1 - Error Identification

Labels or Instructions:

3.3.2 Labels or instructions are provided when content requires user input. (Level A)Understanding Success Criterion 3.3.2

Sufficient Techniques for 3.3.2 - Labels or Instructions

Note: Other techniques may also be sufficient if they meet the success criterion.

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

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

  3. FLASH32: Using auto labeling to associate text labels with form controls (Flash)

  4. FLASH29: Setting the label property for form components (Flash)

  5. FLASH25: Labeling a form control by setting its accessible name (Flash)

  6. PDF10: Providing labels for interactive form controls in PDF documents (PDF)

  7. SL26: Using LabeledBy to Associate Labels and Targets in Silverlight (Silverlight)

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

  9. FLASH8: Adding a group name to the accessible name of a form control (Flash)

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

  11. SL8: Displaying HelpText in Silverlight User Interfaces (Silverlight)

  12. G167: Using an adjacent button to label the purpose of a field

Note: The techniques at the end of the above list should be considered "last resort" and only used when the other techniques cannot be applied to the page. The earlier techniques are preferred because they increase accessibility to a wider user group.

Advisory Techniques for 3.3.2 - Labels or Instructions

Error Suggestion:

3.3.3 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. (Level AA)Understanding Success Criterion 3.3.3

Sufficient Techniques for 3.3.3 - Error Suggestion

Note: Other techniques may also be sufficient if they meet the success criterion.

Situation A: If a mandatory field contains no information:
  1. G83: Providing text descriptions to identify required fields that were not completed

  2. ARIA2: Identifying a required field with the aria-required property (ARIA)

  3. PDF5: Indicating required form controls in PDF forms (PDF)

  4. SL35: Using the Validation and ValidationSummary APIs to Implement Client Side Forms Validation in Silverlight (Silverlight)

Situation B: If information for a field is required to be in a specific data format:
  1. ARIA18: Using aria-alertdialog to Identify Errors (ARIA)

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

  3. G177: Providing suggested correction text

  4. SCR18: Providing client-side validation and alert (Scripting)

  5. SCR32: Providing client-side validation and adding error text via the DOM (Scripting)

  6. FLASH12: Providing client-side validation and adding error text via the accessible description (Flash)

  7. PDF22: Indicating when user input falls outside the required format or values in PDF forms (PDF)

Situation C: Information provided by the user is required to be one of a limited set of values:
  1. ARIA18: Using aria-alertdialog to Identify Errors (ARIA)

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

  3. G177: Providing suggested correction text

  4. SCR18: Providing client-side validation and alert (Scripting)

  5. SCR32: Providing client-side validation and adding error text via the DOM (Scripting)

  6. FLASH12: Providing client-side validation and adding error text via the accessible description (Flash)

  7. PDF22: Indicating when user input falls outside the required format or values in PDF forms (PDF)

Advisory Techniques for 3.3.3 - Error Suggestion
  • 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)

  • Accepting input data in a variety of formats (future link)

  • G199: Providing success feedback when data is submitted successfully

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)

Error Prevention (Legal, Financial, Data):

3.3.4 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: (Level AA)Understanding Success Criterion 3.3.4

  1. Reversible: Submissions are reversible.

  2. Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.

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

Advisory Techniques for 3.3.4 - Error Prevention (Legal, Financial, Data)
Advisory Techniques for 3.3.5 - Help

Error Prevention (All):

3.3.6 For Web pages 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: Submissions are reversible.

  2. Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.

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

Sufficient Techniques for 3.3.6 - Error Prevention (All)

Note: Other techniques may also be sufficient if they meet the success criterion.

  1. Following the sufficient techniques for Success Criterion 3.3.4 for all forms that require the user to submit information.

Compatible:

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

Advisory Techniques for Guideline 4.1

Parsing:

4.1.1 In content implemented using markup languages, elements have complete start and end tags, elements are nested according to their specifications, elements do not contain duplicate attributes, and any IDs are unique, except where the specifications allow these features. (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.

Name, Role, Value:

4.1.2 For all user interface components (including but not limited to: form elements, links and components generated by scripts), the name and role can be programmatically determined; states, properties, and values that can be set by the user can be 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 components. For example, standard HTML controls already meet this success criterion when used according to specification.

Sufficient Techniques for 4.1.2 - Name, Role, Value

Note: Other techniques may also be sufficient if they meet the success criterion.

Situation A: If using a standard user interface component in a markup language (e.g., HTML):
  1. ARIA14: Using aria-label to provide an invisible label where a visible label cannot be used (ARIA)

  2. ARIA16: Using aria-labelledby to provide a name for user interface controls (ARIA)

  3. 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 using technology-specific techniques below:

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 using technology-specific techniques below:

Advisory Techniques for 4.1.2 - Name, Role, Value
  • Providing labels for all form controls that do not have implicit labels (future link)

Conformance Requirements

[Hide Conformance Requirements]

In order for a Web page to conform to WCAG 2.0, all of the following conformance requirements must be satisfied:

1. Conformance Level: One of the following levels of conformance is met in full.

Note 1: Although conformance can only be achieved at the stated levels, authors are encouraged to report (in their claim) any progress toward meeting success criteria from all levels beyond the achieved level of conformance.

Note 2: It is not recommended that Level AAA conformance be required as a general policy for entire sites because it is not possible to satisfy all Level AAA Success Criteria for some content.

Advisory Techniques for Conformance Requirement 1 - Conformance Level
  • Providing reciprocal links between conforming and non-conforming versions (future link)

  • Excluding non-conforming content from search results (future link)

  • Using content negotiation (future link)

  • Not displaying content that relies on technologies that are not accessibility-supported when the technology is turned off or not supported. (future link)

  • Using metadata to allow location of a conforming alternative version from the URI of a non-conforming page (future link)

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

Note 1: For the purpose of determining conformance, alternatives to part of a page's content are considered part of the page when the alternatives can be obtained directly from the page, e.g., a long description or an alternative presentation of a video.

Note 2: Authors of Web pages that cannot conform due to content outside of the author's control may consider a Statement of Partial Conformance.

3. Complete processes: When a Web page is one of a series of Web pages presenting a process (i.e., a sequence of steps that need to be completed in order to accomplish an activity), all Web pages in the process conform at the specified level or better. (Conformance is not possible at a particular level if any page in the process does not conform at that level or better.)

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) conform in order for any page that is part of the process to conform.

4. Only Accessibility-Supported Ways of Using Technologies: Only accessibility-supported ways of using technologies are relied upon to satisfy the success criteria. Any information or functionality that is provided in a way that is not accessibility supported is also available in a way that is accessibility supported. (See Understanding accessibility support.)

5. Non-Interference: If technologies are used in a way that is not accessibility supported, or if they are used in a non-conforming way, then they do not block the ability of users to access the rest of the page. In addition, the Web page as a whole continues to meet the conformance requirements under each of the following conditions:

  1. when any technology that is not relied upon is turned on in a user agent,

  2. when any technology that is not relied upon is turned off in a user agent, and

  3. when any technology that is not relied upon is not supported by a user agent

In addition, the following success criteria apply to all content on the page, including content that is not otherwise relied upon to meet conformance, because failure to meet them could interfere with any use of the page:

Note: If a page cannot conform (for example, a conformance test page or an example page), it cannot be included in the scope of conformance or in a conformance claim.

For more information, including examples, see Understanding Conformance Requirements.