All WCAG criteria
WCAG 2.1·Robust·4.1 Compatible

4.1.1 Parsing

Level A

Markup must be valid: complete tags, no duplicate IDs, properly nested elements. (Removed in WCAG 2.2.)

Why it matters

Modern parsers tolerate broken markup, but assistive tech still struggles with malformed HTML.

Common failure
<div id="main"><span>...</div></span>
Accessible version
<div id="main"><span>...</span></div>

How OnlyEnable handles this

Source-code fix required. No widget can solve this — it requires changes to your content or markup. Our remediation team can help.

Related criteria in 4.1 Compatible