MCPInstall

accessibility

by tech-leads-clubFrontend & Design

Audit and improve web accessibility following WCAG 2.1 guidelines. Use when asked to "improve accessibility", "a11y audit", "WCAG compliance", "screen reader support", "keyboard navigation", or "make accessible". Do NOT use for SEO (use seo), performance (use core-web-vitals), or comprehensive site audits covering multiple areas (use web-quality-audit).

Installs
241
Last 24h
—
Trending rank
—
Security
Not audited

Install

Works with every agent the skills CLI supports.

npx skills add https://github.com/tech-leads-club/agent-skills --skill accessibility
  1. 01

    Install

    Run the command in your project. The CLI asks which agents to install for.

  2. 02

    Describe the task

    Ask your agent for something this skill covers. It loads accessibility automatically when relevant.

  3. 03

    Review the result

    The agent follows the SKILL.md steps, scripts and references bundled with the skill.

SKILL.md

The instructions your agent reads when the skill is triggered.

Accessibility (a11y)

Comprehensive accessibility guidelines based on WCAG 2.1 and Lighthouse accessibility audits. Goal: make content usable by everyone, including people with disabilities.

WCAG Principles: POUR

PrincipleDescription
PerceivableContent can be perceived through different senses
OperableInterface can be operated by all users
UnderstandableContent and interface are understandable
RobustContent works with assistive technologies

Conformance levels

LevelRequirementTarget
AMinimum accessibilityMust pass
AAStandard complianceShould pass (legal requirement in many jurisdictions)
AAAEnhanced accessibilityNice to have

Perceivable

Text alternatives (1.1)

Images require alt text:

<!-- ❌ Missing alt -->
<img src="chart.png" />

<!-- ✅ Descriptive alt -->
<img src="chart.png" alt="Bar chart showing 40% increase in Q3 sales" />

<!-- ✅ Decorative image (empty alt) -->
<img src="decorative-border.png" alt="" role="presentation" />

<!-- ✅ Complex image with longer description -->
<figure>
  <img src="infographic.png" alt="2024 market trends infographic" aria-describedby="infographic-desc" />
  <figcaption id="infographic-desc">
    <!-- Detailed description -->
  </figcaption>
</figure>

Icon buttons need accessible names:

<!-- ❌ No accessible name -->
<button>
  <svg><!-- menu icon --></svg>
</button>

<!-- ✅ Using aria-label -->
<button aria-label="Open menu">
  <svg aria-hidden="true"><!-- menu icon --></svg>
</button>

<!-- ✅ Using visually hidden text -->
<button>
  <svg aria-hidden="true"><!-- menu icon --></svg>
  <span class="visually-hidden">Open menu</span>
</button>

Visually hidden class:

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

Color contrast (1.4.3, 1.4.6)

Text SizeAA minimumAAA enhanced
Normal text (< 18px / < 14px bold)4.5:17:1
Large text (≥ 18px / ≥ 14px bold)3:14.5:1
UI components & graphics3:13:1
/* ❌ Low contrast (2.5:1) */
.low-contrast {
  color: #999;
  background: #fff;
}

/* ✅ Sufficient contrast (7:1) */
.high-contrast {
  color: #333;
  background: #fff;
}

/* ✅ Focus states need contrast too */
:focus-visible {
  outline: 2px solid #005fcc;
  outline-offset: 2px;
}

Don't rely on color alone:

<!-- ❌ Only color indicates error -->
<input class="error-border" />
<style>
  .error-border {
    border-color: red;
  }
</style>

<!-- ✅ Color + icon + text -->
<div class="field-error">
  <input aria-invalid="true" aria-describedby="email-error" />
  <span id="email-error" class="error-message">
    <svg aria-hidden="true"><!-- error icon --></svg>
    Please enter a valid email address
  </span>
</div>

Media alternatives (1.2)

<!-- Video with captions -->
<video controls>
  <source src="video.mp4" type="video/mp4" />
  <track kind="captions" src="captions.vtt" srclang="en" label="English" default />
  <track kind="descriptions" src="descriptions.vtt" srclang="en" label="Descriptions" />
</video>

<!-- Audio with transcript -->
<audio controls>
  <source src="podcast.mp3" type="audio/mp3" />
</audio>
<details>
  <summary>Transcript</summary>
  <p>Full transcript text...</p>
</details>

Operable

Keyboard accessible (2.1)

All functionality must be keyboard accessible:

// ❌ Only handles click
element.addEventListener('click', handleAction)

// ✅ Handles both click and keyboard
element.addEventListener('click', handleAction)
element.addEventListener('keydown', (e) => {
  if (e.key === 'Enter' || e.key === ' ') {
    e.preventDefault()
    handleAction()
  }
})

No keyboard traps:

// Modal focus management
function openModal(modal) {
  const focusableElements = modal.querySelectorAll(
    'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])',
  )
  const firstElement = focusableElements[0]
  const lastElement = focusableElements[focusableElements.length - 1]

  // Trap focus within modal
  modal.addEventListener('keydown', (e) => {
    if (e.key === 'Tab') {
      if (e.shiftKey && document.activeElement === firstElement) {
        e.preventDefault()
        lastElement.focus()
      } else if (!e.shiftKey && document.activeElement === lastElement) {
        e.preventDefault()
        firstElement.focus()
      }
    }
    if (e.key === 'Escape') {
      closeModal()
    }
  })

  firstElement.focus()
}

Focus visible (2.4.7)

/* ❌ Never remove focus outlines */
*:focus {
  outline: none;
}

/* ✅ Use :focus-visible for keyboard-only focus */
:focus {
  outline: none;
}

:focus-visible {
  outline: 2px solid #005fcc;
  outline-offset: 2px;
}

/* ✅ Or custom focus styles */
button:focus-visible {
  box-shadow: 0 0 0 3px rgba(0, 95, 204, 0.5);
}

Skip links (2.4.1)

<body>
  <a href="#main-content" class="skip-link">Skip to main content</a>
  <header><!-- navigation --></header>
  <main id="main-content" tabindex="-1">
    <!-- main content -->
  </main>
</body>

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: #000;
  color: #fff;
  padding: 8px 16px;
  z-index: 100;
}

.skip-link:focus {
  top: 0;
}

Timing (2.2)

// Allow users to extend time limits
function showSessionWarning() {
  const modal = createModal({
    title: 'Session Expiring',
    content: 'Your session will expire in 2 minutes.',
    actions: [
      { label: 'Extend session', action: extendSession },
      { label: 'Log out', action: logout },
    ],
    timeout: 120000, // 2 minutes to respond
  })
}

Motion (2.3)

/* Respect reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

Understandable

Page language (3.1.1)

<!-- ❌ No language specified -->
<html>
  <!-- ✅ Language specified -->
  <html lang="en">
    <!-- ✅ Language changes within page -->
    <p>The French word for hello is <span lang="fr">bonjour</span>.</p>
  </html>
</html>

Consistent navigation (3.2.3)

<!-- Navigation should be consistent across pages -->
<nav aria-label="Main">
  <ul>
    <li><a href="/" aria-current="page">Home</a></li>
    <li><a href="/products">Products</a></li>
    <li><a href="/about">About</a></li>
  </ul>
</nav>

Form labels (3.3.2)

<!-- ❌ No label association -->
<input type="email" placeholder="Email" />

<!-- ✅ Explicit label -->
<label for="email">Email address</label>
<input type="email" id="email" name="email" autocomplete="email" required />

<!-- ✅ Implicit label -->
<label>
  Email address
  <input type="email" name="email" autocomplete="email" required />
</label>

<!-- ✅ With instructions -->
<label for="password">Password</label>
<input type="password" id="password" aria-describedby="password-requirements" />
<p id="password-requirements">Must be at least 8 characters with one number.</p>

Error handling (3.3.1, 3.3.3)

<!-- Announce errors to screen readers -->
<form novalidate>
  <div class="field" aria-live="polite">
    <label for="email">Email</label>
    <input type="email" id="email" aria-invalid="true" aria-describedby="email-error" />
    <p id="email-error" class="error" role="alert">Please enter a valid email address (e.g., name@example.com)</p>
  </div>
</form>

// Focus first error on submit
form.addEventListener('submit', (e) => {
  const firstError = form.querySelector('[aria-invalid="true"]')
  if (firstError) {
    e.preventDefault()
    firstError.focus()

    // Announce error summary
    const errorSummary = document.getElementById('error-summary')
    errorSummary.textContent = `${errors.length} errors found. Please fix them and try again.`
    errorSummary.focus()
  }
})

Robust

Valid HTML (4.1.1)

<!-- ❌ Duplicate IDs -->
<div id="content">...</div>
<div id="content">...</div>

<!-- ❌ Invalid nesting -->
<a href="/"><button>Click</button></a>

<!-- ✅ Unique IDs -->
<div id="main-content">...</div>
<div id="sidebar-content">...</div>

<!-- ✅ Proper nesting -->
<a href="/" class="button-link">Click</a>

ARIA usage (4.1.2)

Prefer native elements:

<!-- ❌ ARIA role on div -->
<div role="button" tabindex="0">Click me</div>

<!-- ✅ Native button -->
<button>Click me</button>

<!-- ❌ ARIA checkbox -->
<div role="checkbox" aria-checked="false">Option</div>

<!-- ✅ Native checkbox -->
<label><input type="checkbox" /> Option</label>

When ARIA is needed:

<!-- Custom tabs component -->
<div role="tablist" aria-label="Product information">
  <button role="tab" id="tab-1" aria-selected="true" aria-controls="panel-1">Description</button>
  <button role="tab" id="tab-2" aria-selected="false" aria-controls="panel-2" tabindex="-1">Reviews</button>
</div>
<div role="tabpanel" id="panel-1" aria-labelledby="tab-1">
  <!-- Panel content -->
</div>
<div role="tabpanel" id="panel-2" aria-labelledby="tab-2" hidden>
  <!-- Panel content -->
</div>

Live regions (4.1.3)

<!-- Status updates -->
<div aria-live="polite" aria-atomic="true" class="status">
  <!-- Content updates announced to screen readers -->
</div>

<!-- Urgent alerts -->
<div role="alert" aria-live="assertive">
  <!-- Interrupts current announcement -->
</div>

// Announce dynamic content changes
function showNotification(message, type = 'polite') {
  const container = document.getElementById(`${type}-announcer`)
  container.textContent = '' // Clear first
  requestAnimationFrame(() => {
    container.textContent = message
  })
}

Testing checklist

Automated testing

# Lighthouse accessibility audit
npx lighthouse https://example.com --only-categories=accessibility

# axe-core
npm install @axe-core/cli -g
axe https://example.com

Manual testing

  • Keyboard navigation: Tab through entire page, use Enter/Space to activate
  • Screen reader: Test with VoiceOver (Mac), NVDA (Windows), or TalkBack (Android)
  • Zoom: Content usable at 200% zoom
  • High contrast: Test with Windows High Contrast Mode
  • Reduced motion: Test with prefers-reduced-motion: reduce
  • Focus order: Logical and follows visual order

Screen reader commands

ActionVoiceOver (Mac)NVDA (Windows)
Start/Stop⌘ + F5Ctrl + Alt + N
Next itemVO + →↓
Previous itemVO + ←↑
ActivateVO + SpaceEnter
Headings listVO + U, then arrowsH / Shift + H
Links listVO + UK / Shift + K

Common issues by impact

Critical (fix immediately)

  1. Missing form labels
  2. Missing image alt text
  3. Insufficient color contrast
  4. Keyboard traps
  5. No focus indicators

Serious (fix before launch)

  1. Missing page language
  2. Missing heading structure
  3. Non-descriptive link text
  4. Auto-playing media
  5. Missing skip links

Moderate (fix soon)

  1. Missing ARIA labels on icons
  2. Inconsistent navigation
  3. Missing error identification
  4. Timing without controls
  5. Missing landmark regions

References

FAQ

What does the accessibility skill do?

Audit and improve web accessibility following WCAG 2.1 guidelines. Use when asked to "improve accessibility", "a11y audit", "WCAG compliance", "screen reader support", "keyboard navigation", or "make accessible". Do NOT use for SEO (use seo), performance (use core-web-vitals), or comprehensive site audits covering multiple areas (use web-quality-audit).

How do I install accessibility?

Run npx skills add https://github.com/tech-leads-club/agent-skills --skill accessibility in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/accessibility/ (personal) or .claude/skills/accessibility/ (project).

Which AI agents can use accessibility?

Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.

Is accessibility safe to install?

No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.

Who maintains accessibility?

It is published by tech-leads-club in tech-leads-club/agent-skills. It has 241 recorded installs.

More from tech-leads-club/agent-skills

View all →

tlc-spec-driven

tech-leads-club/agent-skills

Feature planning and implementation with 4 adaptive phases (Specify, Design, Tasks, Execute). Auto-sizes depth by complexity. Asks every product decision before the spec is approved, writes testable requirements in EARS notation, atomic tasks with a gate and a commit each, and one check per criterion with the test that proves it. Captures that come with the request bind, and each screen is judged against them. Ships deterministic Python scripts so the gates are enforced by code, not memory; the proofs run once at the end, and an independent Verifier (author != verifier) spends its time on mutations and judgement. Use when (1) planning features, (2) implementing with verification and atomic commits, (3) validating an implementation against a spec. Triggers on "specify feature", "discuss feature", "design", "tasks", "implement", "validate", "verify work", "UAT", "record decision", "pause work", "resume work". Do NOT use for pure architecture decomposition analysis or standalone technical

Code Quality & Workflow1.2K installs

subagent-creator

tech-leads-club/agent-skills

Guide for creating AI subagents with isolated context for complex multi-step workflows. Use when users want to create a subagent, specialized agent, verifier, debugger, or orchestrator that requires isolated context and deep specialization. Works with any agent that supports subagent delegation. Triggers on "create subagent", "new agent", "specialized assistant", "create verifier". Do NOT use for Cursor-specific subagents (use cursor-subagent-creator instead).

AI & Agents911 installs

technical-design-doc-creator

tech-leads-club/agent-skills

Creates comprehensive Technical Design Documents (TDD) with mandatory and optional sections through interactive discovery. Use when user asks to "write a design doc", "create a TDD", "technical spec", "architecture document", "RFC", "design proposal", or needs to document a technical decision before implementation. Do NOT use for README files, API docs, or general documentation (use docs-writer instead).

Docs & Writing609 installs

security-best-practices

tech-leads-club/agent-skills

Open the skill to read its SKILL.md instructions.

Code Quality & Workflow361 installs

domain-analysis

tech-leads-club/agent-skills

Open the skill to read its SKILL.md instructions.

AI & Agents359 installs

nestjs-modular-monolith

tech-leads-club/agent-skills

Open the skill to read its SKILL.md instructions.

AI & Agents331 installs

Popular frontend & design skills

View category →

setup-matt-pocock-skills

mattpocock/skills

Configure this repo for the engineering skills: set up its issue tracker, triage label vocabulary, and domain doc layout. Run once before first use of the other engineering skills.

Frontend & Design1.1M installs

frontend-design

anthropics/skills

Guidance for distinctive, intentional visual design when building new UI or reshaping an existing one. Helps with aesthetic direction, typography, and making choices that don't read as templated defaults.

OfficialFrontend & Design1M installs

hyperframes-animation

heygen-com/hyperframes

All animation knowledge for HyperFrames — atomic motion rules, multi-phase scene blueprints, scene transitions, broader motion-design techniques, AND the seven runtime adapters (GSAP default, plus Lottie, Three.js, Anime.js, CSS keyframes, Web Animations API, TypeGPU). Use for any motion or animation task: pick 2-4 rules and compose, or load a blueprint, or look up runtime-specific API (e.g. GSAP eases / Lottie player / Three.js mixer). Also covers auditing an existing composition's choreography (animation map) and 24 named text-animation effects. HyperFrames-native: single paused timeline, seek-safe, deterministic.

Frontend & Design1M installs

prototype

mattpocock/skills

Build a throwaway prototype to answer a design question. Use when the user wants to sanity-check whether a state model or logic feels right, or explore what a UI should look like.

Frontend & Design999.2K installs

hyperframes-core

heygen-com/hyperframes

The HyperFrames composition contract — build one renderable project. Use for composition structure, the data- timing attributes, class="clip", tracks, sub-compositions, variables, framework-owned media playback, deterministic-render rules, and validation. Read before writing composition HTML.

Frontend & Design930.5K installs

vercel-react-best-practices

vercel-labs/agent-skills

React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.

OfficialFrontend & Design843.1K installs