HTML page has lang attribute

Rule Type:
Rule ID:
Last Modified:
March 5, 2020
Accessibility Requirements Mapping:
3.1.1 Language of Page (Level A)
  • Required for conformance to WCAG 2.0 and later on level A and higher
  • Outcome mapping:
    • Any failed outcomes: success criterion is not satisfied
    • All passed outcomes: success criterion needs further testing
    • An inapplicable outcome: success criterion needs further testing
H57: Using language attributes on the html element
  • Not required to conformance to any W3C accessibility recommendation.
  • Outcome mapping:
    • Any failed outcomes: technique is not satisfied
    • All passed outcomes: technique needs further testing
    • An inapplicable outcome: technique needs further testing
Input Aspects:
DOM Tree


This rule checks that an HTML page has a non-empty lang attribute.


This rule applies to any document element if it is an html element that:

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.


Each test target has a lang attribute that is neither empty ("") nor only ASCII whitespace.


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 major accessibility support issues known for this rule.


Test Cases


Passed Example 1

This html element has a lang attribute with a non-empty ("") value.

<html lang="en"></html>


Failed Example 1

This html element does not have a lang attribute.


Failed Example 2

This html element has a lang attribute with an empty ("") value.

<html lang=""></html>

Failed Example 3

This html element has a lang attribute whose value is only ASCII whitespace.

<html lang=" "></html>

Failed Example 4

This html element has no lang attribute, only a xml:lang attribute.

<html xml:lang="en"></html>


Inapplicable Example 1

This rule does not apply to svg element.

<svg xmlns=""></svg>

Inapplicable Example 2

This rule does not apply to math element.




An outcome is a conclusion that comes from evaluating an ACT Rule on a test subject or one of its constituent test target. An outcome can be one of the three following types:

Note: A rule has one passed or failed outcome for every test target. When there are no test targets the rule has one inapplicable outcome. This means that each test subject will have one or more outcomes.

Note: Implementations using the EARL10-Schema can express the outcome with the outcome property. In addition to passed, failed and inapplicable, EARL 1.0 also defined an incomplete outcome. While this cannot be the outcome of an ACT Rule when applied in its entirety, it often happens that rules are only partially evaluated. For example, when applicability was automated, but the expectations have to be evaluated manually. Such “interim” results can be expressed with the incomplete outcome.


This rule was written in the ACT Rules community group, with the support of the EU-funded WAI-Tools Project.


Previous Authors


This is the first version of this ACT rule.

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