WCAG 2.1 Accessibility Standards

WCAG (Web Content Accessibility Guidelines) is a set of criteria that aims to make web content accessible to everyone. Below are the levels, principles, and a practical checklist.

PerceivableOperableUnderstandableRobust

WCAG 2.1 Levels

In practice, AA level is commonly targeted. Level A removes critical barriers; AAA includes advanced improvements and may not be applicable to all content.

A

Basic Requirements

  • Alternative text for non-text content
  • All functionality operable via keyboard
  • Visible focus and logical focus order
  • Meaningful headings and landmark usage
Level A removes critical accessibility barriers.
AA

Recommended Standard

  • Contrast: at least 4.5:1 for text (3:1 for large text)
  • Content remains usable when text is resized up to 200%
  • Consistent navigation and meaningful link text
  • Form errors explained and guidance provided
AA is the target level for most organizations.
AAA

Advanced Level

  • Contrast: 7:1 for text and enhanced readability
  • Extended alternative media and supportive content
  • Advanced error prevention, guidance and tips
  • Additional adjustments to improve readability and clarity
AAA may not be practical for all content.