Can I test both URLs and raw HTML content?

Yes, it provides tools to test public URLs and raw HTML strings.

How can I customize the viewport size for testing?

You can specify viewport width and height parameters when testing URLs or HTML.

Does this server require any API keys or authentication?

No authentication or API keys are required to use this server.

Is this an official Deque Labs product?

No, this server uses Deque's axe-core but is not an official Deque Labs MCP server.

A11ymcp

MCP server for testing web content and HTML snippets for WCAG 2.0/2.1/2.2 accessibility compliance using axe-core.

Quick Install

Automated & IDE Setup

Copy the AI prompt to install this server into Claude Code, Cursor, or another agent — or use 1-click editor setup below.

Add to Cursor Add to VS Code

Not yet automatically verified

We haven't yet run this listing's install command through our automated sandbox check. This isn't a red flag — we're steadily working through the catalog.

Manual Client & Custom JSON ConfigExpand JSON ▾

Client Config & Setup

Choose your client or environment

Target File:~/Library/Application Support/Claude/claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "ronantakizawa-a11ymcp": {
      "command": "npx",
      "args": [
        "-y",
        "a11y-mcp-server"
      ]
    }
  }
}

💡 Paste the JSON block into your client's configuration file under mcpServers, then restart the application.

Overview

This MCP server enables LLMs to analyze web pages and raw HTML strings for accessibility issues based on WCAG standards. It uses Puppeteer and the Deque axe-core API to perform tests including color contrast, ARIA validation, and orientation lock detection. Developers can customize viewport dimensions and specify which WCAG tags to evaluate. Use it to automate accessibility audits within MCP-compatible clients.

Use cases

Test public URLs for WCAG accessibility compliance

Analyze raw HTML snippets for accessibility issues

Validate color contrast ratios against WCAG standards

Check proper usage of ARIA attributes

Detect content enforcing specific screen orientations

Key features

Accessibility testing of URLs and HTML strings

Supports WCAG 2.0, 2.1, and 2.2 compliance levels

Customizable viewport dimensions for testing

Rule exploration with detailed accessibility rule info

Color contrast analysis per WCAG guidelines

ARIA attribute validation and orientation lock detection

Capabilities & Tool Schemas

Inspect callable tools, capabilities, and parameters exposed to AI agents by A11ymcp.

Extracted Tool Capabilities

Accessibility testing of URLs and HTML strings

Supports WCAG 2.0, 2.1, and 2.2 compliance levels

Customizable viewport dimensions for testing

Rule exploration with detailed accessibility rule info

Color contrast analysis per WCAG guidelines

ARIA attribute validation and orientation lock detection

Documentation Overview

Web Accessibility-Testing MCP Server (A11y MCP)

https://github.com/user-attachments/assets/316c6d44-e677-433e-b4d5-63630b4bab2b

A11y MCP is an MCP (Model Context Protocol) server that gives LLMs access to web accessibility testing APIs.

This server uses the Deque Axe-core API and Puppeteer to allow LLMs to analyze web content for WCAG compliance and identify accessibility issues.

Note: This is not an official MCP server from Deque Labs.

Features

Test web pages: Test any public URL for accessibility issues with customizable viewport dimensions
Test HTML snippets: Test raw HTML strings for accessibility issues
WCAG compliance testing: Check content against various WCAG standards (2.0, 2.1, 2.2)
Customizable tests: Specify which accessibility tags/standards to test against
Rule exploration: Get information about available accessibility rules
Color contrast analysis: Check color combinations for WCAG compliance
ARIA validation: Test proper usage of ARIA attributes
Orientation lock detection: Identify content that forces specific screen orientations

Installation

Prerequisites

Node.js 18 or later
An MCP-compatible client (Claude Desktop, Claude Code, VS Code, Cursor, etc.)

Claude Desktop

Edit your MCP configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json
Linux: ~/.config/Claude/claude_desktop_config.json

Add the server to the mcpServers object:

config.json

{
  "mcpServers": {
    "a11y-accessibility": {
      "command": "npx",
      "args": ["-y", "a11y-mcp-server"]
    }
  }
}

Claude Code (CLI)

Terminal

claude mcp add a11y-accessibility -- npx -y a11y-mcp-server

This registers the server for the current project. To make it available across all projects:

Terminal

claude mcp add --scope user a11y-accessibility -- npx -y a11y-mcp-server

Verify the server is registered:

Terminal

claude mcp list

Note: MCP tools become available after restarting your Claude Code session.

VS Code (Copilot)

Add to your VS Code settings.json or .vscode/settings.json:

config.json

{
  "mcp": {
    "servers": {
      "a11y-accessibility": {
        "command": "npx",
        "args": ["-y", "a11y-mcp-server"]
      }
    }
  }
}

Cursor

Add to your Cursor MCP configuration (.cursor/mcp.json):

config.json

{
  "mcpServers": {
    "a11y-accessibility": {
      "command": "npx",
      "args": ["-y", "a11y-mcp-server"]
    }
  }
}

Windsurf

Add to your Windsurf MCP configuration (~/.codeium/windsurf/mcp_config.json):

config.json

{
  "mcpServers": {
    "a11y-accessibility": {
      "command": "npx",
      "args": ["-y", "a11y-mcp-server"]
    }
  }
}

Available Tools

test_accessibility

Tests a URL for accessibility issues.

Parameters:

Parameter	Required	Description
`url`	Yes	The URL of the web page to test
`tags`	No	Array of WCAG tags to test against (e.g., `["wcag2aa"]`)
`width`	No	Viewport width in pixels (default: 1280)
`height`	No	Viewport height in pixels (default: 800)

Example — desktop viewport (default):

config.json

{
  "url": "https://example.com",
  "tags": ["wcag2aa"]
}

Example — mobile viewport (iPhone 12/13):

config.json

{
  "url": "https://example.com",
  "tags": ["wcag2aa"],
  "width": 390,
  "height": 844
}

test_html_string

Tests an HTML string for accessibility issues.

Parameters:

Parameter	Required	Description
`html`	Yes	The HTML content to test
`tags`	No	Array of WCAG tags to test against (e.g., `["wcag2aa"]`)
`width`	No	Viewport width in pixels (default: 1280)
`height`	No	Viewport height in pixels (default: 800)

Example — default viewport:

config.json

{
  "html": "<div><img src='image.jpg'></div>",
  "tags": ["wcag2aa"]
}

Example — mobile viewport:

config.json

{
  "html": "<div><img src='image.jpg'></div>",
  "tags": ["wcag2aa"],
  "width": 375,
  "height": 812
}

get_rules

Get information about available accessibility rules with optional filtering. Returns an array of rule objects, each containing ruleId, description, help, helpUrl, and tags.

Parameters:

Parameter	Required	Description
`tags`	No	Filter rules by tags (e.g., `["wcag2a", "wcag2aa", "best-practice"]`)

Example — filter rules by WCAG 2.1 AA:

config.json

{
  "tags": ["wcag21aa"]
}

Example — get all rules (no filter):

config.json

{}

check_color_contrast

Check if a foreground and background color combination meets WCAG contrast requirements.

Parameters:

Parameter	Required	Description
`foreground`	Yes	Foreground color (e.g., `"#000000"`, `"rgb(0,0,0)"`)
`background`	Yes	Background color (e.g., `"#FFFFFF"`, `"rgb(255,255,255)"`)
`fontSize`	No	Font size in pixels (default: 16)
`isBold`	No	Whether the text is bold (default: false)

Example:

config.json

{
  "foreground": "#777777",
  "background": "#EEEEEE",
  "fontSize": 16,
  "isBold": false
}

check_aria_attributes

Check if ARIA attributes are used correctly in HTML.

Parameters:

Parameter	Required	Description
`html`	Yes	HTML content to test for ARIA attribute usage

Example:

config.json

{
  "html": "<div role='button' aria-pressed='false'>Click me</div>"
}

check_orientation_lock

Check if content forces a specific orientation.

Parameters:

Parameter	Required	Description
`html`	Yes	HTML content to test for orientation lock issues

Example:

config.json

{
  "html": "<html><head><meta name='viewport' content='width=device-width, orientation=portrait'></head><body>Content</body></html>"
}

Response Format

The server returns accessibility test results in structured JSON:

config.json

{
  "violations": [
    {
      "id": "color-contrast",
      "impact": "serious",
      "description": "Ensure the contrast between foreground and background colors meets WCAG 2 AA minimum contrast ratio thresholds",
      "help": "Elements must meet minimum color contrast ratio thresholds",
      "helpUrl": "https://dequeuniversity.com/rules/axe/4.10/color-contrast",
      "affectedNodes": [
        {
          "html": "<div style=\"color: #aaa; background-color: #eee;\">Low contrast text</div>",
          "target": ["div"],
          "failureSummary": "Fix any of the following: Element has insufficient color contrast of 1.98 (foreground color: #aaa, background color: #eee, font size: 12.0pt, font weight: normal)"
        }
      ]
    }
  ],
  "passes": 1,
  "incomplete": 0,
  "inapplicable": 2,
  "timestamp": "2025-04-25T16:45:33.655Z",
  "url": "about:blank",
  "testEngine": {
    "name": "axe-core",
    "version": "4.10.3"
  }
}

WCAG Tags Reference

Common tags you can use with the tags parameter:

Tag	Description
`wcag2a`	WCAG 2.0 Level A
`wcag2aa`	WCAG 2.0 Level AA
`wcag2aaa`	WCAG 2.0 Level AAA
`wcag21a`	WCAG 2.1 Level A
`wcag21aa`	WCAG 2.1 Level AA
`wcag22aa`	WCAG 2.2 Level AA
`best-practice`	Best practices (not strictly WCAG)

Dependencies

License

MIT

Read the full README →View source on GitHub →

Related MCP Servers

View all in Browser Automation View all alternatives

Adoption & maintenance

Factual signals from GitHub, npm, and our automated checks — not a rating.

GitHub stars

Stargazers on the source repository.

npm downloads

892

Package downloads in the last 30 days.

Last commit

6mo ago

Most recent push to the default branch.

Directory activity

1 views

Config copies, upvotes, and views on AllMCPs.

Reviews

No reviews yet — be the first to share how this listing worked for you.

Frequently Asked Questions about A11ymcp

It supports WCAG 2.0, 2.1, and 2.2 compliance testing.

AllMCPs Directory Badge

Full Badge Customizer

Showcase your server listing on GitHub or your project documentation. Embed this dynamic SVG badge to highlight official listing status and live engagement.

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Markdown (GitHub README)

[![AllMCPs](https://allmcps.com/api/badge/ronantakizawa-a11ymcp?style=directory)](https://allmcps.com/mcp/ronantakizawa-a11ymcp)

HTML Embed

<a href="https://allmcps.com/mcp/ronantakizawa-a11ymcp"><img src="https://allmcps.com/api/badge/ronantakizawa-a11ymcp?style=directory" alt="A11ymcp on AllMCPs" /></a>

Technical Specs & Signals

CategoryBrowser Automation

10/11 checks healthy over the last 32d

52Quality signal: Good · 52/100How this signal is calculated ▾

Server availabilityNot measured

Not scored for repo-hosted servers — we can't reach the running server, only its GitHub page. Hosted MCP endpoints are health-checked live.

Verified ownership10/20

Documentation & tools22/30

Adoption & activity7/15

Community engagement0/10

A guidance signal from public completeness & health data — not a user rating. New listings start lower and rise as they add docs, get verified, and grow adoption. Signals we can't observe for a listing are skipped, not counted against it.

Supply-chain signal

No high-severity advisories surfaced by our automated scan.

Critical 0High 0Medium 0Low 0

Scanned 27d ago via OSV.dev · a11y-mcp-server (npm)

★ Spotlight Slot

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More in 📂 Browser Automation →Best MCP servers for Browser Automation →Alternatives to A11ymcp →Install in Claude Desktop Install in Cursor Install in VS Code

A11ymcp

MCP server for testing web content and HTML snippets for WCAG 2.0/2.1/2.2 accessibility compliance using axe-core.

Quick Install

Automated & IDE Setup

Copy the AI prompt to install this server into Claude Code, Cursor, or another agent — or use 1-click editor setup below.

Add to Cursor Add to VS Code

Not yet automatically verified

We haven't yet run this listing's install command through our automated sandbox check. This isn't a red flag — we're steadily working through the catalog.

Manual Client & Custom JSON ConfigExpand JSON ▾

Client Config & Setup

Choose your client or environment

Target File:~/Library/Application Support/Claude/claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "ronantakizawa-a11ymcp": {
      "command": "npx",
      "args": [
        "-y",
        "a11y-mcp-server"
      ]
    }
  }
}

💡 Paste the JSON block into your client's configuration file under mcpServers, then restart the application.

Overview

Use cases

Test public URLs for WCAG accessibility compliance

Analyze raw HTML snippets for accessibility issues

Validate color contrast ratios against WCAG standards

Check proper usage of ARIA attributes

Detect content enforcing specific screen orientations

Key features

Accessibility testing of URLs and HTML strings

Supports WCAG 2.0, 2.1, and 2.2 compliance levels

Customizable viewport dimensions for testing

Rule exploration with detailed accessibility rule info

Color contrast analysis per WCAG guidelines

ARIA attribute validation and orientation lock detection

Capabilities & Tool Schemas

Inspect callable tools, capabilities, and parameters exposed to AI agents by A11ymcp.

Extracted Tool Capabilities

Accessibility testing of URLs and HTML strings

Supports WCAG 2.0, 2.1, and 2.2 compliance levels

Customizable viewport dimensions for testing

Rule exploration with detailed accessibility rule info

Color contrast analysis per WCAG guidelines

ARIA attribute validation and orientation lock detection

Documentation Overview

Web Accessibility-Testing MCP Server (A11y MCP)

https://github.com/user-attachments/assets/316c6d44-e677-433e-b4d5-63630b4bab2b

A11y MCP is an MCP (Model Context Protocol) server that gives LLMs access to web accessibility testing APIs.

This server uses the Deque Axe-core API and Puppeteer to allow LLMs to analyze web content for WCAG compliance and identify accessibility issues.

Note: This is not an official MCP server from Deque Labs.

Features

Test web pages: Test any public URL for accessibility issues with customizable viewport dimensions
Test HTML snippets: Test raw HTML strings for accessibility issues
WCAG compliance testing: Check content against various WCAG standards (2.0, 2.1, 2.2)
Customizable tests: Specify which accessibility tags/standards to test against
Rule exploration: Get information about available accessibility rules
Color contrast analysis: Check color combinations for WCAG compliance
ARIA validation: Test proper usage of ARIA attributes
Orientation lock detection: Identify content that forces specific screen orientations

Installation

Prerequisites

Node.js 18 or later
An MCP-compatible client (Claude Desktop, Claude Code, VS Code, Cursor, etc.)

Claude Desktop

Edit your MCP configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json
Linux: ~/.config/Claude/claude_desktop_config.json

Add the server to the mcpServers object:

config.json

{
  "mcpServers": {
    "a11y-accessibility": {
      "command": "npx",
      "args": ["-y", "a11y-mcp-server"]
    }
  }
}

Claude Code (CLI)

Terminal

claude mcp add a11y-accessibility -- npx -y a11y-mcp-server

This registers the server for the current project. To make it available across all projects:

Terminal

claude mcp add --scope user a11y-accessibility -- npx -y a11y-mcp-server

Verify the server is registered:

Terminal

claude mcp list

Note: MCP tools become available after restarting your Claude Code session.

VS Code (Copilot)

Add to your VS Code settings.json or .vscode/settings.json:

config.json

{
  "mcp": {
    "servers": {
      "a11y-accessibility": {
        "command": "npx",
        "args": ["-y", "a11y-mcp-server"]
      }
    }
  }
}

Cursor

Add to your Cursor MCP configuration (.cursor/mcp.json):

config.json

{
  "mcpServers": {
    "a11y-accessibility": {
      "command": "npx",
      "args": ["-y", "a11y-mcp-server"]
    }
  }
}

Windsurf

Add to your Windsurf MCP configuration (~/.codeium/windsurf/mcp_config.json):

config.json

{
  "mcpServers": {
    "a11y-accessibility": {
      "command": "npx",
      "args": ["-y", "a11y-mcp-server"]
    }
  }
}

Available Tools

test_accessibility

Tests a URL for accessibility issues.

Parameters:

Parameter	Required	Description
`url`	Yes	The URL of the web page to test
`tags`	No	Array of WCAG tags to test against (e.g., `["wcag2aa"]`)
`width`	No	Viewport width in pixels (default: 1280)
`height`	No	Viewport height in pixels (default: 800)

Example — desktop viewport (default):

config.json

{
  "url": "https://example.com",
  "tags": ["wcag2aa"]
}

Example — mobile viewport (iPhone 12/13):

config.json

{
  "url": "https://example.com",
  "tags": ["wcag2aa"],
  "width": 390,
  "height": 844
}

test_html_string

Tests an HTML string for accessibility issues.

Parameters:

Parameter	Required	Description
`html`	Yes	The HTML content to test
`tags`	No	Array of WCAG tags to test against (e.g., `["wcag2aa"]`)
`width`	No	Viewport width in pixels (default: 1280)
`height`	No	Viewport height in pixels (default: 800)

Example — default viewport:

config.json

{
  "html": "<div><img src='image.jpg'></div>",
  "tags": ["wcag2aa"]
}

Example — mobile viewport:

config.json

{
  "html": "<div><img src='image.jpg'></div>",
  "tags": ["wcag2aa"],
  "width": 375,
  "height": 812
}

get_rules

Get information about available accessibility rules with optional filtering. Returns an array of rule objects, each containing ruleId, description, help, helpUrl, and tags.

Parameters:

Parameter	Required	Description
`tags`	No	Filter rules by tags (e.g., `["wcag2a", "wcag2aa", "best-practice"]`)

Example — filter rules by WCAG 2.1 AA:

config.json

{
  "tags": ["wcag21aa"]
}

Example — get all rules (no filter):

config.json

{}

check_color_contrast

Check if a foreground and background color combination meets WCAG contrast requirements.

Parameters:

Parameter	Required	Description
`foreground`	Yes	Foreground color (e.g., `"#000000"`, `"rgb(0,0,0)"`)
`background`	Yes	Background color (e.g., `"#FFFFFF"`, `"rgb(255,255,255)"`)
`fontSize`	No	Font size in pixels (default: 16)
`isBold`	No	Whether the text is bold (default: false)

Example:

config.json

{
  "foreground": "#777777",
  "background": "#EEEEEE",
  "fontSize": 16,
  "isBold": false
}

check_aria_attributes

Check if ARIA attributes are used correctly in HTML.

Parameters:

Parameter	Required	Description
`html`	Yes	HTML content to test for ARIA attribute usage

Example:

config.json

{
  "html": "<div role='button' aria-pressed='false'>Click me</div>"
}

check_orientation_lock

Check if content forces a specific orientation.

Parameters:

Parameter	Required	Description
`html`	Yes	HTML content to test for orientation lock issues

Example:

config.json

{
  "html": "<html><head><meta name='viewport' content='width=device-width, orientation=portrait'></head><body>Content</body></html>"
}

Response Format

The server returns accessibility test results in structured JSON:

config.json

{
  "violations": [
    {
      "id": "color-contrast",
      "impact": "serious",
      "description": "Ensure the contrast between foreground and background colors meets WCAG 2 AA minimum contrast ratio thresholds",
      "help": "Elements must meet minimum color contrast ratio thresholds",
      "helpUrl": "https://dequeuniversity.com/rules/axe/4.10/color-contrast",
      "affectedNodes": [
        {
          "html": "<div style=\"color: #aaa; background-color: #eee;\">Low contrast text</div>",
          "target": ["div"],
          "failureSummary": "Fix any of the following: Element has insufficient color contrast of 1.98 (foreground color: #aaa, background color: #eee, font size: 12.0pt, font weight: normal)"
        }
      ]
    }
  ],
  "passes": 1,
  "incomplete": 0,
  "inapplicable": 2,
  "timestamp": "2025-04-25T16:45:33.655Z",
  "url": "about:blank",
  "testEngine": {
    "name": "axe-core",
    "version": "4.10.3"
  }
}

WCAG Tags Reference

Common tags you can use with the tags parameter:

Tag	Description
`wcag2a`	WCAG 2.0 Level A
`wcag2aa`	WCAG 2.0 Level AA
`wcag2aaa`	WCAG 2.0 Level AAA
`wcag21a`	WCAG 2.1 Level A
`wcag21aa`	WCAG 2.1 Level AA
`wcag22aa`	WCAG 2.2 Level AA
`best-practice`	Best practices (not strictly WCAG)

Dependencies

License

MIT

Read the full README →View source on GitHub →

Related MCP Servers

View all in Browser Automation View all alternatives

Adoption & maintenance

Factual signals from GitHub, npm, and our automated checks — not a rating.

GitHub stars

Stargazers on the source repository.

npm downloads

892

Package downloads in the last 30 days.

Last commit

6mo ago

Most recent push to the default branch.

Directory activity

1 views

Config copies, upvotes, and views on AllMCPs.

Reviews

No reviews yet — be the first to share how this listing worked for you.

Frequently Asked Questions about A11ymcp

It supports WCAG 2.0, 2.1, and 2.2 compliance testing.

AllMCPs Directory Badge

Full Badge Customizer

Showcase your server listing on GitHub or your project documentation. Embed this dynamic SVG badge to highlight official listing status and live engagement.

Badge Style:

Live Dynamic SVG Preview

Markdown (GitHub README)

[![AllMCPs](https://allmcps.com/api/badge/ronantakizawa-a11ymcp?style=directory)](https://allmcps.com/mcp/ronantakizawa-a11ymcp)

HTML Embed

<a href="https://allmcps.com/mcp/ronantakizawa-a11ymcp"><img src="https://allmcps.com/api/badge/ronantakizawa-a11ymcp?style=directory" alt="A11ymcp on AllMCPs" /></a>

Technical Specs & Signals

CategoryBrowser Automation

10/11 checks healthy over the last 32d

52Quality signal: Good · 52/100How this signal is calculated ▾

Server availabilityNot measured

Not scored for repo-hosted servers — we can't reach the running server, only its GitHub page. Hosted MCP endpoints are health-checked live.

Verified ownership10/20

Documentation & tools22/30

Adoption & activity7/15

Community engagement0/10

Supply-chain signal

No high-severity advisories surfaced by our automated scan.

Critical 0High 0Medium 0Low 0

Scanned 27d ago via OSV.dev · a11y-mcp-server (npm)

★ Spotlight Slot

Feature Your MCP Server

Get maximum visibility for your server across our directory, search results, and detail pages.

Spotlight Your Server

Own this project?

Free dofollow backlink: add your website and place the AllMCPs badge on it — no claim needed. We detect it automatically and keep it verified as long as the badge stays live.

Claim & get free dofollow

Share & Embed

Add our SVG badge (dark/light directory styles) or embeddable widget to your site.

Explore more

More in 📂 Browser Automation →Best MCP servers for Browser Automation →Alternatives to A11ymcp →Install in Claude Desktop Install in Cursor Install in VS Code