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Code validation

Applies to

  • Websites


Using standards-compliant code increases the likelihood that all web browsers and assistive technologies will correctly handle your content. If your code contains syntax errors, tags that aren’t nested properly, or other issues that violate the rules of the markup language, screen readers and other assistive technologies might fail when trying to render the content for users. Even pages that seem to look fine in a web browser might have unseen problems for assistive technology users.


WCAG 2.1 success criteria

The issues described on this page, and associated Techniques pages, map to the following success criteria in the W3C’s Web Content Accessibility Guidelines (WCAG) 2.1: