This program can help check documents against certain WCAG (Web Content Accessibility Guidelines) 1.0 and 2.0 checkpoints.
WCAG 1.0 Options
| • | Check against W3C Web Content Accessibility Guidelines 1.0 (WCAG 1.0) - Check this box to enable WCAG 1.0 (new window) accessibility checking. This option has no effect if the Enable accessibility checking option is not checked. This option is enabled by default. |
| • | Group WCAG 1.0 messages by Priority - Check this box to group WCAG 1.0 messages by priority (1, 2, or 3). This option has no effect if the Enable accessibility checking option is not checked or if the Check against W3C Web Content Accessibility Guidelines 1.0 option is not checked. This option is enabled by default. |
| • | WCAG Conformance Level - Choose which WCAG messages, based on priority, you would like displayed. The WCAG define three priority levels and three conformance levels. This option has no effect if the Enable accessibility checking option is not checked or if the Check against W3C Web Content Accessibility Guidelines 1.0 option is not checked. This option's default is Conformance Level "AAA". the highest level of conformance. |
WCAG 2.0 Options
| • | Check against W3C Web Content Accessibility Guidelines 2.0 (WCAG 2.0) - Check this box to enable WCAG 2.0 (new window) accessibility checking. This option has no effect if the Enable accessibility checking option is not checked. This option is enabled by default. |
| • | Group WCAG 2.0 messages by Conformance Level - Check this box to group WCAG 2.0 messages by conformance level ("A", "AA", or "AAA"). This option has no effect if the Enable accessibility checking option is not checked or if the Check against W3C Web Content Accessibility Guidelines 2.0 option is not checked. This option is enabled by default. |
| • | WCAG Conformance Level - Choose which WCAG messages, based on conformance level, you would like displayed. The WCAG define three conformance levels. This option has no effect if the Enable accessibility checking option is not checked or if the Check against W3C Web Content Accessibility Guidelines 2.0 option is not checked. This option's default is Conformance Level "AAA". the highest level of conformance. |
About WCAG 1.0 Accessibility
CSE HTML Validator helps an organization comply (but cannot guarantee compliance) with the W3C's Web Content Accessibility Guidelines 1.0 (WCAG 1.0). These are guidelines for web developers and developers of authoring tools to help make them more accessible to people with disabilities. These guidelines were published as a W3C Recommendation in 1999 and are now superseded by WCAG 2.0.
About WCAG 1.0 Priorities
Developers must satisfy priority 1 checkpoints, should satisfy priority 2 checkpoints, and may address priority 3 checkpoints. See Section 4 of the WCAG 1.0 guidelines for more information.
WCAG 1.0 Items Checked (may not be a complete list)
| • | Displays an error message for missing alternative text ("alt" attribute) for the "applet", "area", "img", and "input" (when type="image") elements. [P1, 1.1] |
| • | Displays an error message for missing alternative representation for the "object" element. [P1, 1.1] |
| • | Displays a warning message for a missing text alternative (in the body) for "applet" elements. [P1, 1.1] (Nev v9.9930) |
| • | Displays a warning message for empty alternative text (alt="") for "area" elements. [P1, 1.1] (New v9.9930) |
| • | Displays a warning message for missing title text ("title" attribute) for "area" elements. [P1, 1.1] (New v9.9930) |
| • | Displays a message for a missing "longdesc" attribute (to specify a text alternative of the frame) for the "frame" and "iframe" elements. [P1, 1.1] |
| • | Displays a message about using a text alternative (in case scripting is turned off or not supported) when the "script" element is used. [P1, 1.1] |
| • | Displays a message to provide redundant text links when the "ismap" attribute is used with the "img" element. [P1, 1.2] |
| • | Displays a warning message if the brightness or color difference of specified foreground and background colors is below minimum recommendations. [P3, 2.2] |
| • | Displays a message about the importance of making sure that documents validate to published formal grammars and are "well formed" if only an accessibility check is done. [P2, 3.2] |
| • | Displays a warning message when presentational elements are used instead of style sheets. [P2, 3.3] |
| • | Displays a warning message about using relative units rather than absolute units in style property values. [P2, 3.4] |
| • | Displays a warning message if heading elements appear out of order. [P2, 3.5] |
| • | Displays a message for missing "lang" and "xml:lang" attributes (to specify the natural primary language of a document) for the "html" element. [P3, 4.3] |
| • | Displays a warning message about using table row and column headers for data tables if the "th" element is not used in the table. [P1, 5.1] |
| • | Displays a message about using markup to associate data cells and header cells in data tables with two or more logical levels of row or column headers. [P2, 5.2] |
| • | Displays a message recommending to avoid using tables for layout (unless they make sense when linearized) and to not use any structural markup for the purpose of visual formatting when the "table" element is used. [P2, 5.3, 5.4] |
| • | Displays a message for a missing "summary" attribute (to provide a brief overview of how data has been organized in the table or a brief explanation of how to navigate or use the table) when the "table" element is used. [P3, 5.5] |
| • | Displays a message that documents should be able to be read without style sheets when a style sheet is used. [P1, 6.1] |
| • | Displays a warning message if "javascript:" is used in the "href" attribute of an "a" element. [P1, 6.3] |
| • | Displays a message about making sure pages are usable when scripts, applets, or other programmatic objects are turned off or not supported when href="#" and an "onclick" attribute is used or when scripts, applets, or other programmatic objects are turned off or not supported. [P1, 6.3] |
| • | Displays a warning message about causing content to blink when the "blink" element is used. [P2, 7.2] |
| • | Displays a warning message if it appears that a meta tag is trying to do a non-zero second page refresh or auto-redirect. [P2, 7.4, 7.5] |
| • | Displays a message recommending client-side image maps instead of server-side image maps when the "ismap" attribute is used with the "img" element. [P1, 9.1] |
| • | Displays a message for device-dependent event handlers like "onmouseout" and "onmouseover" and suggest logical event handlers instead. [P2, 9.3] |
| • | Displays a comment about using keyboard shortcuts to important links (often done using the "accesskey" attribute). [P3, 9.5] |
| • | Displays a comment if "a" elements have been used but not one "accesskey" attribute has been used with any of the "a" elements. [P3, 9.5] |
| • | Displays a message if a "target" attribute is used to open a new window (the message is a warning if the link text does not contain "new window" to notify the user). [P2, 10.1] |
| • | Displays a warning message if adjacent links are not separated by non-link, printable characters. [P3, 10.5] |
| • | Displays a warning message if a frame title does not appear to be useful or meaningful. [P1, 12.1] |
| • | Displays an error message for a missing "title" attribute (to label the frame, describe the contents, and facilitate frame identification and navigation) for the "frame" and "iframe" elements. [P1, 12.1] |
| • | Displays a warning message for "input" (of certain types), "select", and "textarea" control elements if they do not have explicitly associated labels. [P2, 12.4] |
| • | Displays a warning message if the same link text has been used to link to different resources. [P2, 13.1] |
| • | Displays a warning message if the document does not appear to have an appropriate or descriptive title. [P2, 13.2] |
| • | Displays a warning message if there is no "title" element in the "head" section. [P2, 13.2] |
About WCAG 2.0 Accessibility
CSE HTML Validator helps an organization comply (but cannot guarantee compliance) with the W3C's Web Content Accessibility Guidelines 2.0 (WCAG 2.0). These are guidelines for web developers and developers of authoring tools to help make them more accessible to people with disabilities. WCAG 2.0 became a W3C Recommendation in December 2008 and builds on and succeeds WCAG 1.0. The W3C recommends that new content use WCAG 2.0.
About WCAG 2.0 Conformance
Developers must satisfy the minimum level of conformance (level A) to conform with WCAG 2.0. See the conformance section of the recommendation for more information. Also, please remember that automated tools like this one, although very useful, can only check certain guidelines and cannot guarantee conformance at any level. Other checking methods are required.
WCAG 2.0 Items Checked (may not be a complete list)
| • | Displays an error message for missing alt text ("alt" attribute) for the "applet", "area", "img", and "input" (when type="image") elements. [A, 1.1.1] |
| • | Displays a warning message if the alt text contains only whitespace. [A, 1.1.1] |
| • | Displays a warning message if the alt text is empty but the title text is not. [A, 1.1.1] |
| • | Displays a warning message for a missing text alternative (in the body) for "applet" elements. [A, 1.1.1] (New v9.9930) |
| • | Displays an error message for missing alternative representation for "object" elements. [A, 1.1.1] |
| • | Displays an error message for "input" (of certain types), "select", and "textarea" control elements if they do not have explicitly associated labels and do not have "title" attributes. [A, 1.1.1] |
| • | Displays a warning message for empty alternative text (alt="") for the "area" element. [A, 1.1.1] (New v9.9930) |
| • | Displays a warning message for missing title text ("title" attribute) for the "area" element. [A, 1.1.1] (New v9.9930) |
| • | Displays a message for a missing "longdesc" attribute (to specify a text alternative of the frame) for the "frame" and "iframe" elements. [A, 1.1.1] |
| • | Displays a message about providing a text alternative when the "script" element is used. [A, 1.1.1] |
| • | Displays an error message for "a" elements with no link text and that don't contain any images with non-empty alt text. [A, 1.1.1] |
| • | Displays an accessibility message for image maps. [A, 1.1.1, 2.4.4, 2.4.9] |
| • | Displays a warning message if an image appears to be a spacer image and recommends CSS instead. [A, 1.1.1] |
| • | Displays a message about layout tables and the "summary" attribute the first time a "table" element is used. [A, 1.3.1] |
| • | Displays a warning message about using header cells if "th" elements are not used in tables. [A, 1.3.1] |
| • | Displays a message if the "summary" attribute in "table" tags and generates a message if not found. [A, 1.3.1] |
| • | Displays a warning message if heading elements appear out of order. [A, 1.3.1] |
| • | Displays an error message for heading elements containing no text. [A, 1.3.1] (New v10.0125) |
| • | Displays a warning message if a table's caption is the same as the table's summary text. [A, 1.3.1] |
| • | Displays a message if more than one "option" element is used but no "optgroup" elements are used. [A, 1.3.1] |
| • | Displays an error message if the "legend" element is not used in a "fieldset" element. [A, 1.3.1, 3.3.2] |
| • | Displays an error message if groups of radio or checkbox input elements have the same name value but are not in a "fieldset" element. [A, 1.3.1, 3.3.2] |
| • | Displays an error messages for duplication of unique values (like duplicate "id" values). [A, 1.3.1, 4.1.1] (New v10.0125) |
| • | Displays an error messages for "label" references (using the "for" attribute) to non-existent IDs or to non-labelable elements. [A, 1.3.1, 4.1.1] (New v10.0143) |
| • | Displays an error message if a color attribute (like "bgcolor", "link", "text", etc.) is used in the "body" tag but not all the color attributes are used [AA, 1.4.3] (New v10.0145) |
| • | Displays a warning message if a foreground color is specified without a background color or vice versa in a CSS style rule [AA, 1.4.3] (New v10.0146) |
| • | Displays a warning message if a specified foreground and background color is specified in a CSS declaration and the colors do not meet the minimum contrast ratios [AA, 1.4.3; AAA, 1.4.6] |
| • | Displays a warning message when the "bgcolor" attribute is used with "text", "link", and/or the "vlink" attribute in the "body" tag and the colors do not meet the minimum contrast ratios [AA, 1.4.3; AAA, 1.4.6] |
| • | Displays a warning if a font size is specified using an absolute unit and it appears to be for a form control (instead of a relative unit like "em" or a percentage) (http://www.w3.org/TR/WCAG20-TECHS/F80) [AA, 1.4.4] (New v10.0143) |
| • | Displays a message about pausing and blinking if it appears that a gif image or animation is specified in the "src" attribute of elements like "img" and "input". [A, 2.2.2] (New v10.0146) |
| • | Displays an error message for a missing "title" attribute in a "frame" or "iframe" element (requires flag 70 to be enabled). [2.4.1, 4.1.2] |
| • | Displays an error message if a page has a missing or empty title (checks the "title" tag, not the "title" attribute). [A, 2.4.2] |
| • | Displays a warning message for "a" elements that contain an "img" element with alt text that matches the link text. [A, 2.4.4] |
| • | Displays a warning message when an "a" element containing an "img" element preceeds another "a" element with the same "href" value and where the image alt text is the same as the link text for the adjacent "a" element. [A, 2.4.4] |
| • | Displays an error message if the "lang" and "xml:lang" attributes are not used in the "html" tag. [3.1.1] |
| • | Displays a warning message if a "dl" element is used without the "title" attribute. [AAA, 3.1.3] |
| • | Displays a warning message if a form does not appear to contain a submit control. [A, 3.2.2] |
| • | Displays a warning message about changes of context if a "meta" non-zero second refresh tag is found (if AAA conformance checking is enabled) [AAA, 3.2.5] |
| • | Displays a warning message if the text "new window" is not found in the link text or in the "title" value of a link with the "target" attribute [3.2.5] |
| • | Displays a warning message for "input" (of certain types), "select", and "textarea" control elements if they have explicitly associated labels but no "title" attribute for context-sensitive help and level AAA checking is enabled. [AAA, 3.3.5] |
| • | Displays an error messages for various parsing problems, like problems with start and end tags and problems with attribute parsing. [A, 4.1.1] (New v10.0125) |
| • | Displays an error messages for blank (empty) label text. [A, 4.1.2] (New v10.0143) |
