Who this affects
The declared language code is not valid, so assistive technology cannot select the right voice.
How to fix it
Use a valid BCP 47 code such as nl, de, fr or en-GB.
Effort Low · ~2 min
Where this sits in the standard
| WCAG success criterion | Level | EN 301 549 clause |
|---|---|---|
| 3.1.1 Language of Page | A | 301-549, 9.3.1.1 |
EN 301 549 clause 9 applies these criteria to web content. The published version referenced by the European Accessibility Act is V3.2.1, which incorporates WCAG 2.1 level A and AA. More on the standard.
How to check it by hand
View source and check the lang attribute on <html>. Then look for passages in another language — a quotation, a product name, a testimonial — and confirm they carry their own lang attribute.
Automated testing settles roughly a third of the WCAG success criteria. This rule is one an automated tool detects reliably — but a clean automated result is not proof of conformance.
Reference
Deque's technical write-up for this rule: html-lang-valid
See whether your site trips this rule
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