WCAG 2.0

ISO Standard

Published in December 2008, WCAG 2.0 was a major overhaul that introduced the POUR principles and testable success criteria. It became ISO/IEC 40500:2012 in 2012.

Key Information

Published

December 11, 2008

ISO Standard

ISO/IEC 40500:2012 (2012)

Success Criteria

61 criteria (12 Level A, 20 Level AA, 29 Level AAA)

Status

Superseded by WCAG 2.1 (2018)

Still Valid

WCAG 2.0 remains valid for compliance

Backward Compatible

WCAG 2.1 and 2.2 build on 2.0

Major Improvements Over WCAG 1.0

POUR Principles

Introduced the four foundational principles: Perceivable, Operable, Understandable, and Robust

Testable Success Criteria

Each criterion is objectively testable, making compliance verification clearer

Technology Agnostic

Guidelines apply to any web technology, not just HTML

Three Conformance Levels

Level A (minimum), Level AA (recommended), and Level AAA (enhanced)

ISO/IEC 40500:2012

In 2012, WCAG 2.0 was adopted as an ISO/IEC international standard (ISO/IEC 40500:2012). This gave it official recognition beyond the web development community and made it easier for governments and organizations worldwide to reference in their policies and laws.

Note: While WCAG 2.0 is still valid, WCAG 2.2 (or 2.1) is the current recommended version as it includes additional success criteria for mobile accessibility and modern web technologies.