accessibility-audit（可访问性审核）

Resources

scripts/
  validate-accessibility-audit.sh
references/
  accessibility-patterns.md

Accessibility Audit

This skill guides you through performing comprehensive accessibility audits to ensure WCAG 2.1 AA compliance. Use this when validating applications for inclusive design, preparing for accessibility reviews, or remediating accessibility issues.

When to Use This Skill

• Conducting pre-launch accessibility compliance reviews
• Responding to accessibility complaints or legal requirements
• Performing periodic accessibility audits on existing applications
• Validating accessibility after major UI refactors
• Preparing for WCAG 2.1 AA certification
• Onboarding teams to accessibility best practices

Audit Methodology

A systematic accessibility audit follows these phases:

Phase 1: Reconnaissance

Objective: Map components and identify accessibility-critical areas.

Use discover to map the UI surface:

discover:
  queries:
    - id: interactive_components
      type: grep
      pattern: "(button|input|select|textarea|a href)"
      glob: "**/*.{tsx,jsx}"
    - id: form_components
      type: grep
      pattern: "<form|onSubmit|FormProvider"
      glob: "**/*.{tsx,jsx}"
    - id: aria_usage
      type: grep
      pattern: "aria-(label|labelledby|describedby|live|role)"
      glob: "**/*.{tsx,jsx}"
    - id: image_components
      type: grep
      pattern: "(<img|<Image|next/image)"
      glob: "**/*.{tsx,jsx}"
  verbosity: files_only

Identify critical areas:

• Forms and input fields
• Navigation menus and routing
• Modal dialogs and overlays
• Data tables and lists
• Media players (audio/video)
• Custom interactive widgets

Phase 2: Semantic HTML Audit

Objective: Verify proper use of HTML5 semantic elements.

Check Heading Hierarchy

Search for heading usage:

precision_grep:
  queries:
    - id: heading_elements
      pattern: "<h[1-6]|heading.*level"
      glob: "**/*.{tsx,jsx}"
  output:
    format: standard

Common violations:

• Skipping heading levels (h1 -> h3 without h2)
• Multiple h1 elements on a page
• Using headings for visual styling instead of structure
• Missing heading hierarchy in complex components

Correct heading structure:

import { ReactNode } from 'react';

interface PageLayoutProps {
  title: string;
  children: ReactNode;
}

export function PageLayout({ title, children }: PageLayoutProps) {
  return (
    <div className="page-layout">
      {/* Single h1 per page */}
      <h1 className="text-3xl font-bold">{title}</h1>

      <main>
        {children}
      </main>
    </div>
  );
}

interface SectionProps {
  title: string;
  children: ReactNode;
}

export function Section({ title, children }: SectionProps) {
  return (
    <section>
      {/* h2 for main sections */}
      <h2 className="text-2xl font-semibold">{title}</h2>
      {children}
    </section>
  );
}

interface SubsectionProps {
  title: string;
  children: ReactNode;
}

export function Subsection({ title, children }: SubsectionProps) {
  return (
    <div>
      {/* h3 for subsections */}
      <h3 className="text-xl font-medium">{title}</h3>
      {children}
    </div>
  );
}

Check Landmark Regions

Search for landmark usage:

precision_grep:
  queries:
    - id: landmarks
      pattern: "(<header|<main|<nav|<aside|<footer|role=\"(banner|navigation|main|complementary|contentinfo)\")"
      glob: "**/*.{tsx,jsx}"
  output:
    format: files_only

Required landmarks:

• <header> or role="banner" for site header
• <nav> or role="navigation" for navigation
• <main> or role="main" for primary content (exactly one per page)
• <aside> or role="complementary" for sidebars
• <footer> or role="contentinfo" for site footer

Proper landmark structure:

import { ReactNode } from 'react';

interface AppLayoutProps {
  navigation: ReactNode;
  sidebar?: ReactNode;
  children: ReactNode;
}

export function AppLayout({ navigation, sidebar, children }: AppLayoutProps) {
  return (
    <div className="app-layout">
      <header className="site-header">
        <div className="logo">MyApp</div>
        {navigation}
      </header>

      <div className="content-container">
        {sidebar && (
          <aside className="sidebar" aria-label="Filters">
            {sidebar}
          </aside>
        )}

        {/* Exactly one main per page */}
        <main className="main-content">
          {children}
        </main>
      </div>

      <footer className="site-footer">
        <p>&copy; 2026 MyApp. All rights reserved.</p>
      </footer>
    </div>
  );
}

Check List Semantics

Search for list patterns:

precision_grep:
  queries:
    - id: list_elements
      pattern: "<(ul|ol|li|dl|dt|dd)"
      glob: "**/*.{tsx,jsx}"
  output:
    format: files_only

Common violations:

• Using <div> for lists instead of <ul> or <ol>
• Nesting <li> outside of <ul> or <ol>
• Using lists for layout instead of semantic grouping

Semantic list usage:

interface User {
  id: string;
  name: string;
  email: string;
}

interface UserListProps {
  users: User[];
}

export function UserList({ users }: UserListProps) {
  return (
    <ul className="user-list" aria-label="Team members">
      {users.map((user) => (
        <li key={user.id}>
          <span className="user-name">{user.name}</span>
          <span className="user-email">{user.email}</span>
        </li>
      ))}
    </ul>
  );
}

Phase 3: ARIA Patterns Audit

Objective: Validate correct ARIA usage and patterns.

Check ARIA Roles

Search for ARIA role usage:

precision_grep:
  queries:
    - id: aria_roles
      pattern: 'role="(button|link|dialog|alertdialog|menu|menuitem|tab|tabpanel|listbox|option)"'
      glob: "**/*.{tsx,jsx}"
  output:
    format: standard

Common violations:

• Redundant roles on semantic elements (e.g., <button role="button">)
• Using role="button" without keyboard handlers
• Missing required ARIA attributes for complex roles
• Using abstract roles (e.g., role="widget")

Correct ARIA button pattern:

import { MouseEvent, KeyboardEvent } from 'react';

interface CustomButtonProps {
  onClick: () => void;
  disabled?: boolean;
  children: React.ReactNode;
}

export function CustomButton({ onClick, disabled, children }: CustomButtonProps) {
  const handleClick = (e: MouseEvent<HTMLDivElement>) => {
    if (!disabled) {
      onClick();
    }
  };

  const handleKeyDown = (e: KeyboardEvent<HTMLDivElement>) => {
    if (!disabled && (e.key === 'Enter' || e.key === ' ')) {
      e.preventDefault();
      onClick();
    }
  };

  return (
    <div
      role="button"
      tabIndex={disabled ? -1 : 0}
      aria-disabled={disabled}
      onClick={handleClick}
      onKeyDown={handleKeyDown}
      className="custom-button"
    >
      {children}
    </div>
  );
}

Note: Prefer native <button> element when possible. Only use role="button" on non-button elements when absolutely necessary.

Check ARIA Labels and Descriptions

Search for labeling patterns:

precision_grep:
  queries:
    - id: aria_labels
      pattern: "aria-(label|labelledby|describedby)"
      glob: "**/*.{tsx,jsx}"
  output:
    format: context

Common violations:

• Interactive elements without accessible names
• aria-labelledby referencing non-existent IDs
• Redundant labels (both aria-label and aria-labelledby)
• Using aria-label on non-interactive elements

Correct labeling patterns:

import { useId } from 'react';

interface SearchFormProps {
  onSearch: (query: string) => void;
}

export function SearchForm({ onSearch }: SearchFormProps) {
  const searchId = useId();
  const hintId = useId();

  return (
    <form role="search" onSubmit={(e) => {
      e.preventDefault();
      const formData = new FormData(e.currentTarget);
      onSearch(formData.get('query') as string);
    }}>
      <label htmlFor={searchId} className="sr-only">
        Search articles
      </label>
      <input
        id={searchId}
        type="search"
        name="query"
        placeholder="Search..."
        aria-describedby={hintId}
      />
      <p id={hintId} className="text-sm text-gray-600">
        Search by title, author, or keyword
      </p>
      <button type="submit" aria-label="Submit search">
        <SearchIcon aria-hidden="true" />
      </button>
    </form>
  );
}

Check Live Regions

Search for live region usage:

precision_grep:
  queries:
    - id: live_regions
      pattern: 'aria-live="(polite|assertive|off)"|role="(status|alert)"'
      glob: "**/*.{tsx,jsx}"
  output:
    format: standard

Live region best practices:

• Use aria-live="polite" for non-critical updates
• Use aria-live="assertive" or role="alert" for urgent messages
• Use role="status" for status updates (implicitly aria-live="polite")
• Ensure live region exists in DOM before content updates

Accessible notification pattern:

import { ReactNode, useEffect, useState } from 'react';

interface NotificationProps {
  message: string;
  type: 'success' | 'error' | 'info';
  onDismiss: () => void;
}

export function Notification({ message, type, onDismiss }: NotificationProps) {
  useEffect(() => {
    const timer = setTimeout(onDismiss, 5000);
    return () => clearTimeout(timer);
  }, [onDismiss]);

  return (
    <div
      role={type === 'error' ? 'alert' : 'status'}
      aria-live={type === 'error' ? 'assertive' : 'polite'}
      className={`notification notification-${type}`}
    >
      <p>{message}</p>
      <button onClick={onDismiss} aria-label="Dismiss notification">
        <CloseIcon aria-hidden="true" />
      </button>
    </div>
  );
}

Phase 4: Keyboard Navigation Audit

Objective: Ensure full keyboard accessibility.

Check Focus Management

Search for focus-related code:

precision_grep:
  queries:
    - id: focus_management
      pattern: "(focus\\(\\)|autoFocus|tabIndex|useRef.*focus)"
      glob: "**/*.{tsx,jsx,ts}"
  output:
    format: standard

Common violations:

• Missing focus indicators (:focus styles)
• Focus traps in modals without escape mechanism
• Interactive elements with tabIndex="-1" that should be reachable
• Auto-focusing elements on page load unnecessarily

Accessible modal with focus trap:

import { useEffect, useRef, ReactNode } from 'react';
import { createPortal } from 'react-dom';

interface ModalProps {
  isOpen: boolean;
  onClose: () => void;
  title: string;
  children: ReactNode;
}

export function Modal({ isOpen, onClose, title, children }: ModalProps) {
  const modalRef = useRef<HTMLDivElement>(null);
  const previousFocusRef = useRef<HTMLElement | null>(null);

  useEffect(() => {
    if (!isOpen) return;

    // Save previously focused element
    previousFocusRef.current = document.activeElement as HTMLElement;

    // Focus first focusable element in modal
    const focusableElements = modalRef.current?.querySelectorAll(
      'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])'
    );

    if (focusableElements && focusableElements.length > 0) {
      (focusableElements[0] as HTMLElement).focus();
    }

    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key === 'Escape') {
        onClose();
      }

      // Trap focus within modal
      if (e.key === 'Tab' && focusableElements) {
        const firstElement = focusableElements[0] as HTMLElement;
        const lastElement = focusableElements[focusableElements.length - 1] as HTMLElement;

        if (e.shiftKey && document.activeElement === firstElement) {
          e.preventDefault();
          lastElement.focus();
        } else if (!e.shiftKey && document.activeElement === lastElement) {
          e.preventDefault();
          firstElement.focus();
        }
      }
    };

    document.addEventListener('keydown', handleKeyDown);

    return () => {
      document.removeEventListener('keydown', handleKeyDown);
      // Restore focus when modal closes
      previousFocusRef.current?.focus();
    };
  }, [isOpen, onClose]);

  if (!isOpen) return null;

  return createPortal(
    <div className="modal-overlay" onClick={onClose}>
      <div
        ref={modalRef}
        role="dialog"
        aria-modal="true"
        aria-labelledby="modal-title"
        className="modal-content"
        onClick={(e) => e.stopPropagation()}
      >
        <h2 id="modal-title">{title}</h2>
        <div className="modal-body">{children}</div>
        <button onClick={onClose} className="modal-close">
          Close
        </button>
      </div>
    </div>,
    document.body
  );
}

Check Skip Links

Search for skip link implementation:

precision_grep:
  queries:
    - id: skip_links
      pattern: "(skip.*main|skip.*content|skip.*navigation)"
      glob: "**/*.{tsx,jsx}"
  output:
    format: files_only

Skip link implementation:

export function SkipLink() {
  return (
    <a
      href="#main-content"
      className="skip-link"
    >
      Skip to main content
    </a>
  );
}

// CSS (in global styles)
// .skip-link {
//   position: absolute;
//   top: -40px;
//   left: 0;
//   background: #000;
//   color: #fff;
//   padding: 8px;
//   text-decoration: none;
//   z-index: 100;
// }
//
// .skip-link:focus {
//   top: 0;
// }

Check Keyboard Event Handlers

Search for onClick without keyboard support:

precision_grep:
  queries:
    - id: onclick_handlers
      pattern: "onClick=\\{"
      glob: "**/*.{tsx,jsx}"
  output:
    format: locations

Manual review: For each onClick handler on a non-button/non-link element, verify:

• Element has role="button" or appropriate role
• Element has tabIndex={0} for keyboard focus
• onKeyDown handler responds to Enter and Space keys

Accessible click handler pattern:

import { MouseEvent, KeyboardEvent } from 'react';

interface ClickableCardProps {
  title: string;
  onClick: () => void;
}

export function ClickableCard({ title, onClick }: ClickableCardProps) {
  const handleKeyDown = (e: KeyboardEvent<HTMLDivElement>) => {
    if (e.key === 'Enter' || e.key === ' ') {
      e.preventDefault();
      onClick();
    }
  };

  return (
    <div
      role="button"
      tabIndex={0}
      onClick={onClick}
      onKeyDown={handleKeyDown}
      className="clickable-card"
    >
      <h3>{title}</h3>
    </div>
  );
}

Phase 5: Screen Reader Support Audit

Objective: Verify screen reader compatibility.

Check Visually Hidden Text

Search for sr-only patterns:

precision_grep:
  queries:
    - id: sr_only
      pattern: "(sr-only|visually-hidden|screen-reader)"
      glob: "**/*.{tsx,jsx,css,scss}"
  output:
    format: files_only

Visually hidden text for icons:

interface IconButtonProps {
  onClick: () => void;
  ariaLabel: string;
  icon: React.ReactNode;
}

export function IconButton({ onClick, ariaLabel, icon }: IconButtonProps) {
  return (
    <button onClick={onClick} aria-label={ariaLabel}>
      {icon}
      <span className="sr-only">{ariaLabel}</span>
    </button>
  );
}

// CSS for sr-only class:
// .sr-only {
//   position: absolute;
//   width: 1px;
//   height: 1px;
//   padding: 0;
//   margin: -1px;
//   overflow: hidden;
//   clip: rect(0, 0, 0, 0);
//   white-space: nowrap;
//   border-width: 0;
// }

Check aria-hidden Usage

Search for aria-hidden:

precision_grep:
  queries:
    - id: aria_hidden
      pattern: 'aria-hidden="true"'
      glob: "**/*.{tsx,jsx}"
  output:
    format: standard

Common violations:

• aria-hidden="true" on interactive elements (buttons, links)
• aria-hidden="true" on content that should be accessible
• Decorative icons without aria-hidden="true"

Correct aria-hidden usage:

interface ButtonWithIconProps {
  onClick: () => void;
  label: string;
}

export function ButtonWithIcon({ onClick, label }: ButtonWithIconProps) {
  return (
    <button onClick={onClick}>
      {/* Icon is decorative, hide from screen readers */}
      <CheckIcon aria-hidden="true" />
      {/* Label provides accessible text */}
      <span>{label}</span>
    </button>
  );
}

Phase 6: Color and Contrast Audit

Objective: Ensure sufficient color contrast and no color-only information.

Check Contrast Ratios

Use browser DevTools or external tools:

• Chrome DevTools: Inspect element -> Accessibility pane -> Contrast ratio
• Firefox DevTools: Inspector -> Accessibility panel
• axe DevTools browser extension
• Lighthouse accessibility audit

WCAG 2.1 AA requirements:

• Normal text (< 18pt): 4.5:1 minimum contrast ratio
• Large text (>= 18pt or >= 14pt bold): 3:1 minimum contrast ratio
• UI components and graphics: 3:1 minimum contrast ratio

Search for color definitions:

precision_grep:
  queries:
    - id: color_definitions
      pattern: "(bg-|text-|color:|background:)"
      glob: "**/*.{tsx,jsx,css,scss}"
  output:
    format: count_only

Accessible color palette (Tailwind example):

// tailwind.config.ts
import type { Config } from 'tailwindcss';

const config: Config = {
  theme: {
    extend: {
      colors: {
        // Accessible color palette with documented contrast ratios
        primary: {
          50: '#f0f9ff',
          100: '#e0f2fe',
          600: '#0284c7', // 4.54:1 on white (WCAG AA)
          700: '#0369a1', // 7.09:1 on white (WCAG AAA)
          900: '#0c4a6e', // 13.14:1 on white
        },
        // Error color with good contrast
        error: {
          600: '#dc2626', // 4.51:1 on white
          700: '#b91c1c', // 6.70:1 on white
        },
        // Success color
        success: {
          600: '#16a34a', // 4.51:1 on white
          700: '#15803d', // 6.68:1 on white
        },
      },
    },
  },
};

export default config;

Check Color-Only Information

Search for status indicators:

precision_grep:
  queries:
    - id: status_colors
      pattern: "(bg-red|bg-green|bg-yellow|text-red|text-green|text-yellow)"
      glob: "**/*.{tsx,jsx}"
  output:
    format: standard

Manual review: Ensure status is conveyed through multiple means (color + icon + text).

Accessible status indicator:

type Status = 'success' | 'warning' | 'error' | 'info';

interface StatusBadgeProps {
  status: Status;
  message: string;
}

const statusConfig: Record<Status, { icon: React.ReactNode; className: string }> = {
  success: { icon: <CheckCircleIcon />, className: 'bg-green-100 text-green-800' },
  warning: { icon: <AlertTriangleIcon />, className: 'bg-yellow-100 text-yellow-800' },
  error: { icon: <XCircleIcon />, className: 'bg-red-100 text-red-800' },
  info: { icon: <InfoIcon />, className: 'bg-blue-100 text-blue-800' },
};

export function StatusBadge({ status, message }: StatusBadgeProps) {
  const { icon, className } = statusConfig[status];

  return (
    <div className={`flex items-center gap-2 px-3 py-2 rounded ${className}`}>
      {/* Icon provides visual indicator beyond color */}
      <span aria-hidden="true">{icon}</span>
      {/* Text provides clear status information */}
      <span>{message}</span>
    </div>
  );
}

Check Forced Colors Mode

Search for forced-colors media query:

precision_grep:
  queries:
    - id: forced_colors
      pattern: "@media.*forced-colors|prefers-contrast"
      glob: "**/*.{css,scss,tsx,jsx}"
  output:
    format: files_only

Support Windows High Contrast Mode:

/* Ensure borders are visible in forced-colors mode */
.card {
  border: 1px solid #e5e7eb;
}

@media (forced-colors: active) {
  .card {
    border: 1px solid CanvasText;
  }
}

/* Ensure custom controls are visible */
.custom-checkbox {
  border: 2px solid #3b82f6;
}

@media (forced-colors: active) {
  .custom-checkbox {
    border: 2px solid ButtonText;
  }

  .custom-checkbox:checked {
    background-color: Highlight;
  }
}

Phase 7: Forms and Validation Audit

Objective: Ensure forms are accessible and error handling is clear.

Check Form Labels

Search for input elements:

precision_grep:
  queries:
    - id: input_elements
      pattern: "<input|<textarea|<select"
      glob: "**/*.{tsx,jsx}"
  output:
    format: locations

Manual review: Verify each input has an associated label via:

• <label> with matching htmlFor attribute
• aria-label attribute
• aria-labelledby pointing to label element

Common violations:

• Placeholder-only inputs without labels
• Labels without htmlFor attribute
• Multiple inputs sharing one label

Accessible form pattern:

import { useId, FormEvent } from 'react';

interface FormData {
  email: string;
  password: string;
}

interface LoginFormProps {
  onSubmit: (data: FormData) => Promise<void>;
}

export function LoginForm({ onSubmit }: LoginFormProps) {
  const emailId = useId();
  const passwordId = useId();
  const emailErrorId = useId();
  const passwordErrorId = useId();

  const handleSubmit = async (e: FormEvent<HTMLFormElement>) => {
    e.preventDefault();
    const formData = new FormData(e.currentTarget);
    await onSubmit({
      email: formData.get('email') as string,
      password: formData.get('password') as string,
    });
  };

  return (
    <form onSubmit={handleSubmit} noValidate>
      <div className="form-field">
        {/* Explicit label with htmlFor */}
        <label htmlFor={emailId}>
          Email address
        </label>
        <input
          id={emailId}
          type="email"
          name="email"
          required
          aria-required="true"
          aria-describedby={emailErrorId}
          autoComplete="email"
        />
        {/* Error message linked via aria-describedby */}
        <p id={emailErrorId} className="error-message" role="alert">
          {/* Error text populated on validation */}
        </p>
      </div>

      <div className="form-field">
        <label htmlFor={passwordId}>
          Password
        </label>
        <input
          id={passwordId}
          type="password"
          name="password"
          required
          aria-required="true"
          aria-describedby={passwordErrorId}
          autoComplete="current-password"
        />
        <p id={passwordErrorId} className="error-message" role="alert">
          {/* Error text populated on validation */}
        </p>
      </div>

      <button type="submit">
        Sign in
      </button>
    </form>
  );
}

Check Error Handling

Search for error patterns:

precision_grep:
  queries:
    - id: error_messages
      pattern: "(error|invalid|required).*message"
      glob: "**/*.{tsx,jsx,ts}"
  output:
    format: standard

Accessible error handling:

import { useState, useId } from 'react';

interface FieldError {
  field: string;
  message: string;
}

interface FormWithValidationProps {
  onSubmit: (data: Record<string, string>) => void;
}

export function FormWithValidation({ onSubmit }: FormWithValidationProps) {
  const [errors, setErrors] = useState<FieldError[]>([]);
  const nameId = useId();
  const nameErrorId = useId();
  const errorSummaryId = useId();

  const handleSubmit = (e: React.FormEvent<HTMLFormElement>) => {
    e.preventDefault();
    const formData = new FormData(e.currentTarget);
    const name = formData.get('name') as string;

    // Validation
    const newErrors: FieldError[] = [];
    if (!name || name.length < 2) {
      newErrors.push({ field: 'name', message: 'Name must be at least 2 characters' });
    }

    if (newErrors.length > 0) {
      setErrors(newErrors);
      // Focus error summary for screen readers
      document.getElementById(errorSummaryId)?.focus();
      return;
    }

    setErrors([]);
    onSubmit({ name });
  };

  const nameError = errors.find((e) => e.field === 'name');

  return (
    <form onSubmit={handleSubmit} noValidate>
      {/* Error summary at top of form */}
      {errors.length > 0 && (
        <div
          id={errorSummaryId}
          role="alert"
          aria-labelledby="error-summary-title"
          className="error-summary"
          tabIndex={-1}
        >
          <h2 id="error-summary-title">There are {errors.length} errors</h2>
          <ul>
            {errors.map((error) => (
              <li key={error.field}>
                <a href={`#${error.field}`}>{error.message}</a>
              </li>
            ))}
          </ul>
        </div>
      )}

      <div className="form-field">
        <label htmlFor={nameId}>Name</label>
        <input
          id={nameId}
          name="name"
          aria-required="true"
          aria-invalid={nameError ? 'true' : 'false'}
          aria-describedby={nameError ? nameErrorId : undefined}
        />
        {nameError && (
          <p id={nameErrorId} className="error-message" role="alert">
            {nameError.message}
          </p>
        )}
      </div>

      <button type="submit">Submit</button>
    </form>
  );
}

Check Required Fields

Search for required field indicators:

precision_grep:
  queries:
    - id: required_fields
      pattern: "(required|aria-required)"
      glob: "**/*.{tsx,jsx}"
  output:
    format: files_only

Accessible required field indicator:

interface RequiredFieldLabelProps {
  htmlFor: string;
  children: React.ReactNode;
}

export function RequiredFieldLabel({ htmlFor, children }: RequiredFieldLabelProps) {
  return (
    <label htmlFor={htmlFor}>
      {children}
      {/* Visual indicator */}
      <span className="text-red-600" aria-hidden="true"> *</span>
      {/* Screen reader text */}
      <span className="sr-only"> (required)</span>
    </label>
  );
}

Phase 8: Media Accessibility Audit

Objective: Ensure images, videos, and audio content are accessible.

Check Image Alt Text

Search for images:

precision_grep:
  queries:
    - id: img_elements
      pattern: "(<img|<Image|next/image)"
      glob: "**/*.{tsx,jsx}"
  output:
    format: standard

Manual review: Verify each image has:

• Meaningful alt text for content images
• Empty alt="" for decorative images
• Alt text that describes function for linked images

Common violations:

• Missing alt attribute
• Generic alt text ("image", "photo", "icon")
• Redundant alt text ("image of...", "picture of...")
• Alt text describing file name ("IMG_1234.jpg")

Accessible image patterns:

import Image from 'next/image';

interface ProductImageProps {
  src: string;
  productName: string;
}

// Content image with descriptive alt
export function ProductImage({ src, productName }: ProductImageProps) {
  return (
    <Image
      src={src}
      alt={`${productName} product photo`}
      width={400}
      height={400}
    />
  );
}

// Decorative image with empty alt
export function DecorativePattern() {
  return (
    <div className="background-pattern">
      <Image
        src="/patterns/dots.svg"
        alt=""
        fill
        aria-hidden="true"
      />
    </div>
  );
}

// Functional image (icon button)
interface DeleteButtonProps {
  onDelete: () => void;
}

export function DeleteButton({ onDelete }: DeleteButtonProps) {
  return (
    <button onClick={onDelete} aria-label="Delete item">
      <Image
        src="/icons/trash.svg"
        alt=""
        width={20}
        height={20}
        aria-hidden="true"
      />
    </button>
  );
}

Check Video Captions

Search for video elements:

precision_grep:
  queries:
    - id: video_elements
      pattern: "(<video|<track)"
      glob: "**/*.{tsx,jsx}"
  output:
    format: standard

Accessible video with captions:

interface AccessibleVideoProps {
  src: string;
  captionsSrc: string;
  title: string;
}

export function AccessibleVideo({ src, captionsSrc, title }: AccessibleVideoProps) {
  return (
    <video controls aria-label={title}>
      <source src={src} type="video/mp4" />
      {/* Captions for deaf/hard of hearing users */}
      <track
        kind="captions"
        src={captionsSrc}
        srcLang="en"
        label="English captions"
        default
      />
      {/* Fallback text */}
      <p>
        Your browser does not support the video element.
        <a href={src}>Download the video</a>
      </p>
    </video>
  );
}

Check Reduced Motion

Search for animations:

precision_grep:
  queries:
    - id: animations
      pattern: "(animate|transition|prefers-reduced-motion)"
      glob: "**/*.{tsx,jsx,css,scss}"
  output:
    format: files_only

Respect prefers-reduced-motion:

import { motion, useReducedMotion } from 'framer-motion';

interface AnimatedCardProps {
  children: React.ReactNode;
}

export function AnimatedCard({ children }: AnimatedCardProps) {
  const shouldReduceMotion = useReducedMotion();

  return (
    <motion.div
      initial={{ opacity: 0, y: shouldReduceMotion ? 0 : 20 }}
      animate={{ opacity: 1, y: 0 }}
      transition={{
        duration: shouldReduceMotion ? 0 : 0.3,
      }}
    >
      {children}
    </motion.div>
  );
}

CSS approach:

/* Default: animated */
.card {
  transition: transform 0.3s ease;
}

.card:hover {
  transform: scale(1.05);
}

/* Reduced motion: disable animations */
@media (prefers-reduced-motion: reduce) {
  .card {
    transition: none;
  }

  .card:hover {
    transform: none;
  }
}

Automated Testing

Precision Tool Workflow

Run comprehensive accessibility checks:

discover:
  queries:
    # Missing alt attributes
    - id: missing_alt
      type: grep
      pattern: "<img(?![^>]*alt=)"
      glob: "**/*.{tsx,jsx}"

    # onClick without keyboard handler
    - id: onclick_no_keyboard
      type: grep
      pattern: 'onClick=\\{(?!.*onKeyDown)'
      glob: "**/*.{tsx,jsx}"

    # Non-button with role=button without keyboard
    - id: role_button_no_keyboard
      type: grep
      pattern: 'role="button"(?!.*onKeyDown)'
      glob: "**/*.{tsx,jsx}"

    # Missing form labels
    - id: unlabeled_inputs
      type: grep
      pattern: "<input(?![^>]*aria-label)(?![^>]*id=)"
      glob: "**/*.{tsx,jsx}"

    # Heading level skips
    - id: heading_usage
      type: grep
      pattern: "<h[1-6]"
      glob: "**/*.{tsx,jsx}"
  verbosity: locations

Browser-Based Testing

Run these tools for comprehensive automated testing:

1. Lighthouse Accessibility Audit npx lighthouse https://localhost:3000 --only-categories=accessibility --view
2. axe DevTools

- Install: axe DevTools Chrome Extension - Run: F12 -> axe DevTools -> Scan

1. Pa11y CI npm install --save-dev pa11y-ci npx pa11y-ci --sitemap https://yoursite.com/sitemap.xml

Audit Reporting

Structure Findings by WCAG Criteria

Report template:

# Accessibility Audit Report

**Date:** 2026-02-16
**Auditor:** [Name]
**WCAG Version:** 2.1 Level AA
**Pages Audited:** 12

## Executive Summary

- **Critical Issues:** 3
- **Serious Issues:** 8
- **Moderate Issues:** 15
- **Minor Issues:** 22

## Findings by WCAG Principle

### 1. Perceivable

#### 1.1.1 Non-text Content (Level A) - FAIL

**Issue:** 12 images missing alt text

**Location:**
- `src/components/ProductCard.tsx:45`
- `src/components/Gallery.tsx:78`

**Impact:** Screen reader users cannot understand image content

**Recommendation:**

// Before <img src="/product.jpg" />

// After <img src="/product.jpg" alt="Blue cotton t-shirt" />

#### 1.4.3 Contrast (Minimum) (Level AA) - FAIL

**Issue:** Primary button text has 3.2:1 contrast ratio (requires 4.5:1)

**Location:** `src/styles/globals.css:45`

**Impact:** Low vision users may not be able to read button text

**Recommendation:**

/* Before: #60a5fa on #3b82f6 = 3.2:1 */ .btn-primary { background: #3b82f6; color: #60a5fa; }

/* After: white on #2563eb = 4.5:1 */ .btn-primary { background: #2563eb; color: #ffffff; }

### 2. Operable

#### 2.1.1 Keyboard (Level A) - FAIL

**Issue:** Custom dropdown not keyboard accessible

**Location:** `src/components/Dropdown.tsx`

**Impact:** Keyboard users cannot operate dropdown

**Recommendation:** Implement arrow key navigation and Enter/Space activation

### 3. Understandable

#### 3.3.2 Labels or Instructions (Level A) - FAIL

**Issue:** Form inputs missing visible labels

**Location:** `src/components/ContactForm.tsx:23-45`

**Recommendation:** Add explicit `<label>` elements with `htmlFor` attributes

### 4. Robust

#### 4.1.2 Name, Role, Value (Level A) - FAIL

**Issue:** Custom checkbox missing ARIA states

**Location:** `src/components/CustomCheckbox.tsx`

**Recommendation:** Add `aria-checked` state and `role="checkbox"`

## Priority Actions

1. **Critical:** Add alt text to all images (affects 100% of screen reader users)
2. **Critical:** Fix keyboard navigation in dropdown (blocks keyboard users)
3. **High:** Fix color contrast on primary buttons (affects ~4.5% of users)
4. **High:** Add form labels (affects screen reader and cognitive users)

Related Skills

• code-review - Apply accessibility checks during code review
• component-architecture - Design accessible component APIs
• testing-strategy - Include accessibility in test suites

References

• WCAG 2.1 Guidelines
• ARIA Authoring Practices Guide (APG)
• WebAIM Contrast Checker
• A11y Project Checklist