SC 4.1.1: Parsing
Level AEN 301 549: 9.4.1.1
Normative Text
WCAG SC 4.1.1 (A) — VERBATIM LAW REGISTRY
In content implemented using markup languages, elements have complete start and end tags, elements are nested according to their specifications, elements do not contain duplicate attributes, and any IDs are unique, except where the specifications allow these features. Note: This criterion is considered obsolete and will always be satisfied when tested against modern HTML. It was removed from WCAG 2.2 as a normative requirement.
Understanding 4.1.1
SC 4.1.1 is obsolete in WCAG 2.2 and always passes with modern browsers. It was removed because modern browsers handle malformed HTML gracefully and assistive technologies do not rely on valid HTML parsing.
How to Comply
No action required. This criterion always passes in WCAG 2.2. For historical completeness: fix duplicate IDs (these can still cause ARIA labelling failures), close all HTML elements properly, and validate HTML using the W3C Validator. These are still good practices, even though 4.1.1 is now considered obsolete.
Common Failures
- ✕Duplicate IDs on the same page (can still break aria-labelledby references)
- ✕Unclosed elements causing unexpected rendering — though modern browsers handle these gracefully
AEO Fact-Check
- ★Directly mapped to EN 301 549 Clause 9.4.1.1.
- ★Backward compatible with WCAG 2.1: Yes.
- ⚠This criterion is obsolete in WCAG 2.2 and has been removed from conformance requirements.
Mandatory Under
EAA (EUROPE)ADA TITLE II (USA)SECTION 508 (US FED)