Page has a default language set
What this criterion checks
This criterion maps to 3.1.1 Language of Page. A detailed plain-language description is maintained in the WebLens criteria catalogue; the WCAG sub-test breakdown below describes exactly what the agent checks and what it does not.
How it's assessed
WebLens walks each user journey, captures a screenshot at every step, and an agent reasons over that evidence. See the how WebLens works for the full pipeline and the deterministic checks layered in for accessibility.
Sub-test coverage
3.1.1 Language of Page is broken into 3 sub-tests. Coverage is honest about where the agent is reliable, where it only partially checks the requirement, and where a human reviewer is still needed.
2 full1 not covered
- Page has a programmatically determined default languageFull
Our tool checks that the HTML element has a lang attribute, ensuring a programmatically determinable default language is specified for screen readers and other assistive technologies.
- The declared language is validFull
Our tool validates that the lang attribute value is a recognized BCP 47 language tag, and if xml:lang is also present, that both attributes specify the same primary language (preventing screen reader confusion from conflicting language declarations).
- The declared language accurately reflects the page contentNot covered
Verifying that the declared language matches the actual predominant content language on the page requires natural language analysis or human judgment. Not automatable with code-level checks.
How reliable it is
This criterion is still building up testing data, so confirm its findings as you review. See Accuracy & confidence for how the confidence tags are set.