Web Accessibility Hub: Central Guide to WCAG 2.2

Introduction

Web accessibility is the practice of designing and building sites that people with disabilities can perceive, understand, navigate, and interact with without barriers. The reference standard is WCAG (Web Content Accessibility Guidelines) 2.2, published by the W3C, which organizes its requirements around four principles known as POUR: Perceivable, Operable, Understandable, and Robust.

The UXR SEO Analyzer automatically checks several of these accessibility signals—alt text, form labels, focus indicators, color contrast, and keyboard navigation—because an accessible page is almost always also a better-structured page for SEO and for AI-driven search systems.

This hub brings the site's accessibility articles together into a single curated index, organized by the four WCAG principles, and links to the deeper guides on the topic.

The Four WCAG Principles (POUR)

Principle	What it requires	Example criterion
Perceivable	Information and interface components must be presentable to users in ways they can perceive	1.1.1 Non-text Content (alt text)
Operable	Interface components and navigation must be operable without relying on a single input method	2.1.1 Keyboard
Understandable	Information and the operation of the interface must be understandable	3.3.2 Labels or Instructions
Robust	Content must be robust enough to be reliably interpreted by a wide range of user agents, including assistive technology	4.1.2 Name, Role, Value

Conformance Levels: A, AA, AAA

WCAG defines three conformance levels, each building on the previous one:

• Level A: the minimum level. It covers the most basic barriers that prevent some people with disabilities from accessing content.
• Level AA: meets all Level A and AA success criteria. It's the standard most accessibility laws and policies require, and the recommended target for most sites.
• Level AAA: meets all criteria across all three levels. It offers further improvements, but the W3C itself notes it is not recommended as a general requirement for entire sites, since some AAA criteria cannot be satisfied for all types of content.

For most projects, targeting Level AA is the practical recommendation: it balances real accessibility with implementation feasibility.

What's New in WCAG 2.2

WCAG 2.2 is the latest version of the guidelines and adds new success criteria focused on users with motor, cognitive, and low-vision needs. Among the most relevant:

• 2.4.11 Focus Not Obscured (Minimum, AA): the component with keyboard focus must not be entirely hidden by overlapping content (sticky headers, chat widgets, banners).
• 2.5.8 Target Size (Minimum, AA): clickable/touch targets must be at least 24×24px, with defined exceptions.
• 2.4.13 Focus Appearance (AAA): requires a focus indicator with a defined minimum area and contrast.
• 3.3.7 Redundant Entry (A): users should not be asked to re-enter information they already provided earlier in the same process.

These criteria add to the already-established ones from WCAG 2.1/2.0 (alt text, contrast, keyboard navigation, form labels, etc.), which remain the foundation of any accessibility audit.

Accessibility Article Index

The following articles cover, in detail, the WCAG criteria most frequently audited by the UXR SEO Analyzer:

Perceivable

• Alt Text Explained — Requirements of criterion 1.1.1 Non-text Content and how to write effective alt text.
• Color Contrast Explained — Minimum ratios from criterion 1.4.3 (4.5:1 normal text, 3:1 large text) and how to measure them.

Operable

• Keyboard Navigation Explained — What criterion 2.1.1 Keyboard requires and how to verify all functionality is operable without a mouse.
• Focus Indicators Explained — Criterion 2.4.7 Focus Visible: why outline: none without an alternative breaks accessibility.

Understandable

• Form Labels Explained — Criteria 1.3.1 and 3.3.2: why a placeholder never replaces a <label>.

Related Hubs

To go deeper than this general index, two hubs cover specific accessibility sub-areas in detail:

• WCAG 2.2 Compliance Hub — Full implementation roadmap, testing tools, an accessibility statement template, and a reference of all success criteria by principle.
• Accessible Components Hub — ARIA and keyboard patterns for building interface components (menus, modals, tabs) that are accessible by design.

Most Common Issues by Principle

Before diving into each article, this table summarizes the most frequent accessibility issues the UXR SEO Analyzer detects in real audits, grouped by the POUR principles:

Principle	Typical issue	WCAG criterion
Perceivable	Images missing an alt attribute, or with empty alt on informative content	1.1.1 (A)
Perceivable	Light gray text on a white background, below 4.5:1	1.4.3 (AA)
Operable	Custom components (dropdowns, carousels) unreachable with Tab	2.1.1 (A)
Operable	outline: none applied without an alternative visible focus state	2.4.7 (AA)
Understandable	Form fields relying only on a placeholder as a label	1.3.1 / 3.3.2 (A)
Robust	ARIA widgets with a role but no computable accessible name	4.1.2 (A)

Each row in this table maps to a dedicated article in the index above, explaining the criterion in detail and how to fix it.

How to Start an Accessibility Audit

For teams just getting started, the recommended order is:

1. Automated scan: run a tool like the UXR SEO Analyzer or axe-core to catch objective issues (missing alt text, contrast, missing labels).
2. Keyboard review: navigate the entire page using only Tab, Shift+Tab, Enter, and Escape, checking that focus is always visible and in a logical order.
3. Screen reader review: test at least one key page with NVDA, VoiceOver, or TalkBack.
4. Prioritized fixes: tackle Level A criteria first, then AA, following the articles linked in this hub.

Why This Is Also SEO

Accessibility and SEO share technical signals: semantic HTML, correct heading hierarchy, descriptive alt text, and links with clear purpose benefit screen readers, search engine crawlers, and the content-extraction systems used by language models alike. Auditing accessibility with a tool like the UXR SEO Analyzer isn't an isolated compliance exercise—it's part of the same technical-quality work that improves rankings.

References

1. W3C - WCAG 2.2 Specification
2. W3C WAI - What's New in WCAG 2.2
3. W3C WAI - WCAG 2 Level AA Conformance
4. WebAIM - WCAG 2 Checklist
5. W3C WAI - Understanding Success Criterion 2.5.8 Target Size
6. W3C WAI - Understanding Success Criterion 2.4.11 Focus Not Obscured (Minimum)