What's Changing in WCAG 3.0?

WCAG is the international standard guideline for web accessibility. The current latest version is 2.2, and work is underway on the next version, 3.0.

WCAG 3.0 is still at the Working Draft stage, and is expected to be published as an official Recommendation no earlier than 2028, or possibly 2030 or later.

WCAG 3.0 will undergo major content revisions. Here's a summary of the key changes coming from WCAG 2.x.

* The following content is from the draft stage. Content may change before the official recommendation is finalized.

Changes to Structure and Terminology

• "Success Criteria" will be renamed to "Outcomes"
• Three-layer structure: Guidelines, Outcomes, and Methods
• As of the current draft, 174 outcomes are defined—a significant increase from WCAG 2.1 (78 outcomes) and 2.2 (86 outcomes). This number may decrease in the future through consolidation or removal.
• The name changes from "Web Content Accessibility Guidelines" to "W3C Accessibility Guidelines," expanding scope beyond web content to include apps and other digital products

Expanded scope

• From web pages to all digital products (web, apps, PDF, ePub, AR, VR, voice assistants, etc.)
• "Page" is replaced with "View," accommodating structures with screen transitions like mobile apps

Redesigned evaluation system

• Bronze, Silver, and Gold—three-tier rating replaces the traditional A, AA, AAA levels
• Each outcome is evaluated on a five-point scale from 0 (very poor) to 4 (excellent)
• Scoring shifts to a flexible model reflecting the diverse functional needs of people with disabilities
• Bronze level is the baseline conformance level, broadly equivalent to WCAG 2.1 Level AA
• Silver and Gold build on Bronze, requiring more comprehensive implementation and user evaluation

Flexibility in conformance assessment

• Not just the entire site, but a series of operations such as checkout and payment can claim conformance on a process-by-process basis
• Emphasis on continuous improvement and evaluation in real-world usage environments
• User-generated content (UGC: posts, comments, photos, videos, etc.) is also considered in the evaluation scope

Introduction of functional categories

• Classification based on "functional abilities for use" rather than "disability types" (for example: using non-visual, limited vision, difficulty with memory, etc.)
• Each outcome is mapped to its corresponding functional category, and assessments are also reflected by category
• Similar approach to "functional performance criteria" in Section 508 and EN 301 549

Backward compatibility

• No backward compatibility with WCAG 2.x due to significant differences in the assessment model and scoring
• Content conforming to WCAG 2.2 (A/AA) is expected to meet many of the minimum-level (Bronze) requirements of the new standard, but additional testing and compliance with new evaluation metrics will be necessary.

Change in contrast ratio calculation method (APCA adoption)

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

Characteristics of APCA

• Takes font size and weight into account (thin text scores lower)
• Results change when text and background are reversed
• Prioritizes perceptual uniformity of contrast, reflecting more realistic readability
• Significantly reduces false judgments that occurred with WCAG 2.x (cases that are actually hard or easy to read)

For example, combinations like white text on an orange background were often marked as "failed" due to insufficient contrast under the traditional standard (WCAG 2.x).
However, with APCA, evaluation is aligned with actual human vision, so "sufficiently large or bold text" is approved—resulting in an evaluation that better balances design freedom with accessibility.

Summary

WCAG 3.0 represents significant evolution from WCAG 2.x and is expected to become a more comprehensive guideline suited to modern digital environments. However, since the evaluation method changes fundamentally, there is no backward compatibility with WCAG 2.x.

WCAG 2 is not being discontinued and will remain in place. Given that WCAG 2.x is currently adopted as a legal standard in many countries and regions, I believe WCAG 2.x will persist as a legal foundation while WCAG 3.0 will be operated in parallel as an ideal or best practice.

Understanding the direction of changes being considered in WCAG 3.0 is highly beneficial and serves as an important guideline for planning future web accessibility services. At Liberogic, we are preparing to incorporate new approaches while closely following the development process.

Reference: W3C Group Draft Note 04 September 2025