Web Accessibility Cheat Sheet

Updated 2026-03-10

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Web accessibility ensures digital content and applications are usable by everyone—including people with visual, auditory, motor, or cognitive disabilities—through standards like WCAG (Web Content Accessibility Guidelines) and ARIA (Accessible Rich Internet Applications). It's not just a legal requirement under laws like the ADA and Section 508, but a fundamental principle of inclusive design: when you build for accessibility, you create better experiences for all users—whether someone is navigating by keyboard, using a screen reader, experiencing low vision, or simply using a mobile device in bright sunlight. What makes accessibility critical in 2026 is the April 24 deadline for WCAG 2.1 Level AA compliance for public entities, the nine new success criteria in WCAG 2.2, and the growing use of AI-powered testing tools that catch issues earlier in development—shifting accessibility from retrofit to foundation, where proper semantic HTML and ARIA attributes are not afterthoughts but core architectural decisions that determine whether your site works for 15% of the world's population.

What This Cheat Sheet Covers

This topic spans 20 focused tables and 141 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.

Table 1: WCAG Principles and Conformance LevelsTable 2: Semantic HTML Elements for AccessibilityTable 3: ARIA Landmark Roles and Page StructureTable 4: ARIA Attributes for Labels and DescriptionsTable 5: ARIA Roles for Interactive WidgetsTable 6: Keyboard Navigation and Focus ManagementTable 7: Color Contrast and Visual DesignTable 8: Form AccessibilityTable 9: Images and Media AccessibilityTable 10: Heading Structure and Document OutlineTable 11: Tables AccessibilityTable 12: WCAG 2.2 New Success Criteria (2026 Focus)Table 13: Screen Reader Testing and CompatibilityTable 14: Automated Accessibility Testing ToolsTable 15: Common ARIA Patterns and WidgetsTable 16: Hidden Content TechniquesTable 17: Mobile and Touch AccessibilityTable 18: Animation and Motion AccessibilityTable 19: Language and InternationalizationTable 20: Text Resizing and Reflow

Table 1: WCAG Principles and Conformance Levels

Principle	Example	Description
Perceivable	Alt text for images, captions for video	• Information must be presentable in ways users can perceive—not just visual • includes text alternatives, captions, and color contrast.
Operable	Full keyboard navigation support	• Interface components must be operable through keyboard, mouse, touch, or assistive tech • includes keyboard access and sufficient time to interact.
Understandable	Clear error messages, consistent navigation	Content and operation must be understandable—predictable behavior, readable text, clear instructions, and helpful error identification.
Robust	Valid HTML, compatible with assistive tech	Content must be robust enough to be reliably interpreted by current and future user agents, including assistive technologies.

Table 1: WCAG Principles and Conformance Levels

Principle	Example	Description
Perceivable	Alt text for images, captions for video	• Information must be presentable in ways users can perceive—not just visual • includes text alternatives, captions, and color contrast.
Operable	Full keyboard navigation support	• Interface components must be operable through keyboard, mouse, touch, or assistive tech • includes keyboard access and sufficient time to interact.
Understandable	Clear error messages, consistent navigation	Content and operation must be understandable—predictable behavior, readable text, clear instructions, and helpful error identification.
Robust	Valid HTML, compatible with assistive tech	Content must be robust enough to be reliably interpreted by current and future user agents, including assistive technologies.