The declared page language is not valid

Automated check html-lang-valid, run with axe-core

WCAG

3.1.1 Language of Page (Level A)

Severity

Serious: completable, but painful

Typical effort

Quick win, under 1 hour

Category

Page structure

Who this affects

Screen reader users.

Why it matters

An invalid code is treated as no declaration at all, producing the wrong pronunciation.

How to fix it

Use a valid BCP 47 code such as en, nl, de, fr, en-GB.

Related checks: Page structure

• The page has no title
• Headings contain no text
• Iframes have no title
• Several frames share the same title
• Heading levels are skipped or out of order
• The page does not declare its language
• The lang and xml:lang attributes disagree
• The page header is nested inside another region

All checks