To ensure correct pronunciation, screen readers use a different sound library for each language they support. Screen readers can switch between these language libraries easily, but only if a web page specifies which language to read for a given piece of content.
To ensure correct pronunciation of the page as a whole, you must specify a valid BCP 47 language for the
How the Lighthouse invalid
lang value audit fails #
Lighthouse flags pages whose
<html> element doesn't have a valid value for its
Note that the
<html> element does not have a
[lang] attribute audit checks whether a
lang attribute is present. This audit checks whether the value for that attribute is valid.
The Lighthouse Accessibility score is a weighted average of all the accessibility audits. See the Lighthouse accessibility scoring post for more information.
How to fix an invalid HTML
lang attribute #
To ensure your page's content is pronounced correctly for screen reader users, use a valid language code in the
lang attribute of the
For example, this sample code sets the language of the document to English: