Why it matters
Invalid HTML can break screen reader navigation and cause unpredictable behavior.
Common violations
- Duplicate IDs on the page
- Unclosed elements
- Improper nesting of interactive elements
Code examples
Bad
<button><a href="/">Home</a></button>Good
<a class="btn" href="/">Home</a>How to fix
Validate HTML, avoid duplicate IDs, and ensure elements are properly nested.
Related criteria
Related resources
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