What Changes in WCAG 3.0?

WCAG is the international standard guideline for web accessibility. The current latest version is 2.2, and the next version, 3.0, is under development.

WCAG 3.0 is still at the Working Draft stage. It is expected to be published as a formal Recommendation no earlier than 2028, and possibly not until 2030 or later.

WCAG 3.0 is planned to undergo a major overhaul. Here is an overview of the key changes from WCAG 2.x.

Note: The following content reflects the draft stage and may change before the formal Recommendation is published.

Changes in Structure and Terminology

• "Success Criteria" Changed to "Outcomes"
• The structure is now three layers: Guidelines, Outcomes, and Methods.
• The current draft defines 174 Outcomes, a significant increase from the 78 in WCAG 2.1 (86 in 2.2). This number may decrease as Outcomes are consolidated or removed.
• Renamed from "Web Content Accessibility Guidelines" to "W3C Accessibility Guidelines," expanding beyond "web content" to cover apps and other digital products

Expanded scope

• Shifting from a focus on web pages to covering all digital products (web, apps, PDF, ePub, AR, VR, voice assistants, and more)
• "Pages" are replaced with "views," supporting structures with screen transitions such as mobile apps

Overhauled rating system

• Replaces the previous A / AA / AAA levels with a three-tier rating of Bronze, Silver, and Gold
• Each outcome is rated on a five-point scale from 0 (very poor) to 4 (excellent)
• Scoring moves to a flexible model that better reflects the diverse functional needs of people with disabilities
• Bronze is the baseline conformance level, roughly equivalent to WCAG 2.1 Level AA
• Silver and Gold build on Bronze, requiring more comprehensive implementation and user evaluation

Flexibility in Conformance Assessment

• Conformance can be claimed not only for entire sites, but also for process-based flows such as checkout or money transfers.
• Emphasis on continuous improvement and evaluation in real-world usage environments
• User-generated content (UGC, such as posts, comments, photos, and videos) is also in scope.

Introduction of Functional Categories

• Classification is based on functional ability rather than disability type (e.g., not using vision, limited vision, memory difficulties).
• Each outcome is linked to a relevant functional category, and results are also reflected by category.
• The approach is similar to the "functional performance criteria" in Section 508 and EN 301 549.

Backward Compatibility

• Because the evaluation model and scoring differ significantly, there is no backward compatibility with WCAG 2.x.
• WCAG 2.2 (A and AA) conformant content is expected to meet most of the minimum-level (Bronze) requirements of the new standard, but additional support for new tests and evaluation metrics is needed

Change to the contrast ratio calculation method (introduction of APCA)

• Uses the new APCA (Advanced Perceptual Contrast Algorithm) method instead of traditional ratios such as 4.5:1
• Evaluated using "Lc values" (0 to approximately 106) that account for human perceptual characteristics
• Results differ between light and dark backgrounds, reflecting how human vision actually works
• Guideline Lc values are as follows
  • Lc 90: Text requiring high readability (recommended)
  • Lc 75: Standard body text (recommended)
  • Lc 60: Minimum value for regular text
  • Lc 45: Minimum value for large text (18pt or larger, or bold)
  • Lc 30: Absolute minimum value for all text
  • Lc 15: Invisible threshold (difficult to perceive)

Features of APCA

• Accounts for font size and weight (thin characters receive lower scores)
• Swapping text and background colors changes the result
• Emphasizes perceptual uniformity of contrast, reflecting more realistic readability
• Significantly reduces misjudgments under WCAG 2.x (text that is actually hard or easy to read)

For example, combinations such as white text on an orange background were often marked as "fail" under traditional standards (WCAG 2.x) due to insufficient contrast.
However, because APCA evaluates contrast based on how humans actually see, text that is large and thick enough is judged acceptable, offering an evaluation that balances design freedom with accessibility.

Summary

WCAG 3.0 is expected to evolve significantly from WCAG 2.x into a comprehensive guideline better suited to today's digital environment. However, because the evaluation methodology fundamentally changes, it is not backward compatible with WCAG 2.x.

WCAG 2 will not be abolished and will continue to exist. Given that many countries and regions currently adopt WCAG 2.x as a legal basis, I expect WCAG 2.x to remain as the legal foundation, while WCAG 3.0 operates in parallel as an ideal or best-practice reference.

Understanding the direction of the changes being considered for WCAG 3.0 is highly valuable and provides an important guideline for planning future accessibility work. At Liberogic, we are following the development process closely and preparing to incorporate the new concepts as they take shape.

Reference: W3C Group Draft Note 04 September 2025