Declare the page language
The lang attribute tells Google which language/region to rank the page for and lets screen readers use the right pronunciation — an accessibility (WCAG) requirement. Missing it muddies international ranking.
How to fix
Set the lang attribute on the root <html> element to the page’s language (and region where relevant). Add hreflang if you serve multiple languages.
<html lang="en">
Detected automatically by the SEOlvl SEO Health audit (check lang). Run a free audit or see the full issue library.