WCAG 3.1.1 — Language of Page
The page's language must be declared in the markup: <html lang="de">.
What this means for a store
A one-line fix, but when it is missing a screen reader pronounces the page with the wrong language's phonetic rules — German product copy read with English pronunciation is close to unintelligible. It bites hardest on multilingual EU storefronts: if the language switcher translates the content but leaves the lang attribute untouched, every translated version is announced wrongly.
The failures we see most often
No lang attribute on the html element at all.
Why it happens: It was omitted when the theme scaffold was built. It has no visual effect, so nobody notices.
lang="en" left hard-coded while the page is served in German or French.
Why it happens: The theme ships with an English default; the translation plugin changes the content and never touches the root attribute.
An invalid or wrong-variant code, such as lang="english" or a page that is really en-GB declared as something else.
Why it happens: The value is typed by hand without checking the BCP 47 list.
How to check it yourself
- View source and look at the opening html tag — is lang present?
- Switch to another language with the site's own switcher and check the source again. Did lang change?
- On a multilingual store, check every locale. Usually only the default one is correct.
Fixing it, by platform
- Shopify — Language of Page Theme code: the html tag in layout/theme.liquid.
- WooCommerce — Language of Page Theme header template (header.php), the html tag.
- Webflow — Language of Page Project Settings, General, Site language; per-locale under Localization.
- Wix — Language of Page Settings, Language & Region; per-language if the Multilingual app is installed.
- Squarespace — Language of Page Settings, Language & Region.
What this page covers
What follows is the practical meaning of a WCAG 2.2 success criterion. Automated tests catch only a portion of accessibility issues, so a clean scan result does not mean compliance. Platform paths vary by version and theme.
Source
The formal definition of this criterion: W3C — Understanding Language of Page