WCAG 2.1 AA Checklist: The Complete Guide for 2026

The Web Content Accessibility Guidelines (WCAG) 2.1 Level AA is the standard that courts, regulators, and accessibility professionals point to when evaluating whether a website is accessible. If your organization needs to achieve compliance, you need a clear checklist to work from.

This guide covers the key WCAG 2.1 AA success criteria organized by the four core principles: Perceivable, Operable, Understandable, and Robust (POUR). For a prioritized, action-oriented version, see our ADA compliance checklist.

Principle 1: Perceivable

Content must be presentable in ways that all users can perceive.

• 1.1.1 Non-text Content — All images, icons, and non-text elements must have text alternatives (alt text) that serve an equivalent purpose. Decorative images should use empty alt attributes.
• 1.2.1-1.2.5 Time-based Media — Pre-recorded audio needs transcripts. Pre-recorded video needs captions and audio descriptions. Live video needs real-time captions.
• 1.3.1 Info and Relationships — Use semantic HTML: proper headings (h1-h6), lists, table headers, form labels. Structure conveyed visually must also be conveyed programmatically.
• 1.3.2 Meaningful Sequence — The DOM order must match the visual reading order.
• 1.3.3 Sensory Characteristics — Instructions must not rely solely on shape, size, visual location, or sound.
• 1.3.4 Orientation — Content must not be locked to a single display orientation (portrait or landscape).
• 1.3.5 Identify Input Purpose — Input fields for personal data (name, email, phone) must use appropriate autocomplete attributes.
• 1.4.1 Use of Color — Color must not be the only means of conveying information.
• 1.4.2 Audio Control — Any audio that auto-plays for more than 3 seconds must have a pause or stop mechanism.
• 1.4.3 Contrast (Minimum) — Normal text requires a 4.5:1 contrast ratio. Large text (18pt or 14pt bold) requires 3:1.
• 1.4.4 Resize Text — Text must be resizable up to 200% without loss of content or functionality.
• 1.4.5 Images of Text — Avoid using images for text content when real text can achieve the same visual result.
• 1.4.10 Reflow — Content must reflow at 320px width without horizontal scrolling.
• 1.4.11 Non-text Contrast — UI components and graphical objects require a 3:1 contrast ratio against adjacent colors.
• 1.4.12 Text Spacing — Content must remain functional when users override line height, paragraph spacing, letter spacing, and word spacing.
• 1.4.13 Content on Hover or Focus — Tooltips and popovers must be dismissible, hoverable, and persistent.

Principle 2: Operable

UI components and navigation must be operable by all users.

• 2.1.1 Keyboard — All functionality must be available via keyboard alone.
• 2.1.2 No Keyboard Trap — Users must be able to navigate away from any component using the keyboard.
• 2.1.4 Character Key Shortcuts — Single-character keyboard shortcuts must be remappable or deactivatable.
• 2.2.1 Timing Adjustable — If content has time limits, users must be able to extend or disable them.
• 2.2.2 Pause, Stop, Hide — Moving, blinking, or auto-updating content must have controls to pause or stop it.
• 2.3.1 Three Flashes — No content may flash more than three times per second.
• 2.4.1-2.4.7 Navigation — Provide skip links, descriptive page titles, logical focus order, visible focus indicators, descriptive link text, and multiple ways to find pages.
• 2.5.1-2.5.4 Input Modalities — Pointer gestures must have single-pointer alternatives. Pointer actions must be cancellable. Labels must match accessible names. Motion-activated functions need alternatives.

Principle 3: Understandable

• 3.1.1-3.1.2 Readable — Set the page language attribute. Identify language changes within content.
• 3.2.1-3.2.4 Predictable — Focus and input must not trigger unexpected context changes. Navigation must be consistent. Components must be identified consistently.
• 3.3.1-3.3.4 Input Assistance — Identify errors clearly. Provide labels and instructions. Suggest corrections. Allow review before submission for legal or financial data.

Principle 4: Robust

• 4.1.1 Parsing — HTML must be well-formed with no duplicate IDs or broken nesting.
• 4.1.2 Name, Role, Value — All UI components must have accessible names, correct roles, and programmatically determinable states.
• 4.1.3 Status Messages — Status messages (success, error, progress) must be communicated to assistive technology via ARIA live regions.

Using this checklist effectively

Manually checking every criterion across every page is not practical for most websites. The most efficient approach is to start with an automated scan that covers the machine-testable criteria — roughly 30-40% of WCAG 2.1 AA. Litmus scans against axe-core rules mapped to these criteria and generates reports showing exactly where your site fails.

Automated scanning gives you a prioritized starting point. From there, you can layer in manual checks for criteria that require human judgment — like whether alt text is actually meaningful, or whether the tab order makes logical sense.

Bookmark this checklist, run your first scan, and start working through violations by severity. Accessibility is not a one-time project — it is an ongoing practice that should be baked into your development workflow.