Audit html-has-lang
Ensure every HTML document has a lang attribute
Impact:
WCAG-Konformität:
- AWCAG 3.1.1
Issue type:
failureHTML page has lang attribute
This rule checks that an HTML page has a non-empty `lang` attribute.
Applicability
This rule applies to any document element if it is an html
element for which all the following are true:
- is in a top-level browsing context; and
- has a node document with a content type of
text/html
.
Note: html
elements within iframe
and object
elements are not applicable as iframe
and object
elements create nested browsing contexts. However, as these elements are meant to provide a layer of isolation, the declared language of their parent browsing context will likely not be inherited, making it possible for empty lang
attributes in nested browsing contexts to also cause accessibility issues.
Expectation
Each test target has a lang
attribute value that is neither empty (""
) nor only ASCII whitespace.
Background
Assumptions
The language of the page can be set by other methods than the lang
attribute, for example using HTTP headers or the meta
element. These methods are not supported by all assistive technologies. This rule assumes that these other methods are insufficient to satisfying Success Criterion 3.1.1: Language of Page.
Accessibility Support
There are no accessibility support issues known.
Related rules
Bibliography
- Understanding Success Criterion 3.1.1: Language of Page
- H57: Using language attributes on the html element
- RFC 5646: Tags for Identifying Languages
- The
lang
andxml:lang
attributes
Test Cases
Passed
Passed Example 1
This html
element has a lang
attribute with a non-empty (""
) value.
<html lang="en">
<body>
The quick brown fox jumps over the lazy dog.
</body>
</html>
Failed
Failed Example 1
This html
element does not have a lang
attribute.
<html>
<body>
The quick brown fox jumps over the lazy dog.
</body>
</html>
Failed Example 2
This html
element has a lang
attribute with an empty (""
) value.
<html lang="">
<body>
The quick brown fox jumps over the lazy dog.
</body>
</html>
Failed Example 3
This html
element has a lang
attribute whose value is only ASCII whitespace.
<html lang=" ">
<body>
The quick brown fox jumps over the lazy dog.
</body>
</html>
Failed Example 4
This html
element has no lang
attribute, only a xml:lang
attribute.
<html xml:lang="en">
<body>
The quick brown fox jumps over the lazy dog.
</body>
</html>
Inapplicable
Inapplicable Example 1
This rule does not apply to an svg
element.
<svg xmlns="http://www.w3.org/2000/svg" lang="en">
<text>
The quick brown fox jumps over the lazy dog.
</text>
</svg>
Inapplicable Example 2
This rule does not apply to a math
element.
<math lang="en">
The quick brown fox jumps over the lazy dog.
</math>
Autoren: Jey Nandakumar
Vorherige Autoren: Annika Nietzio
Finanzierung: WAI-Tools