A11y
This server gives Claude five tools to audit web accessibility in HTML: check_alt_text scans images for missing or weak alt attributes, check_heading_hierarchy validates h1-h6 nesting and outputs a visual tree, check_color_contrast calculates WCAG contrast ratios for color pairs, validate_aria catches role misuse and missing properties, and check_form_accessibility ensures inputs have labels and fieldsets. You'd reach for this when reviewing markup for compliance issues or teaching an agent to spot common accessibility problems like unlabeled form fields, skipped heading levels, or aria-hidden on focusable elements. It runs over stdio and returns structured findings rather than browser automation.
- tools
- 5
- transport
- STDIO
- last updated
- Mar 22, 2026
Tools
5 toolsPublic tool metadata for what this MCP can expose to an agent.
check_alt_textAnalyze images in HTML for missing, empty, or low-quality alt text.
Analyze images in HTML for missing, empty, or low-quality alt text.
No parameter schema in public metadata yet.
check_heading_hierarchyValidate heading structure for proper nesting and content quality.
Validate heading structure for proper nesting and content quality.
No parameter schema in public metadata yet.
check_color_contrastCheck WCAG 2.x contrast ratio for foreground/background color pairs.
Check WCAG 2.x contrast ratio for foreground/background color pairs.
No parameter schema in public metadata yet.
validate_ariaValidate ARIA attributes on HTML elements.
Validate ARIA attributes on HTML elements.
No parameter schema in public metadata yet.
check_form_accessibilityAudit form elements for accessibility compliance.
Audit form elements for accessibility compliance.
No parameter schema in public metadata yet.
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mcp-a11y-tools
Web accessibility analysis tools for AI agents, served over the Model Context Protocol (MCP).
Tools
check_alt_text
Analyze images in HTML for missing, empty, or low-quality alt text.
- Detects missing
altattributes - Identifies decorative images (
alt=""withrole="presentation") - Flags low-quality alt text (e.g., "image", "photo", filenames)
- Checks linked images,
<input type="image">, and<area>elements
check_heading_hierarchy
Validate heading structure for proper nesting and content quality.
- Verifies h1-h6 order with no skipped levels
- Ensures a single
<h1>per page - Detects empty, too-short, or too-long headings
- Supports
role="heading"witharia-level - Returns a visual tree of the heading outline
check_color_contrast
Check WCAG 2.x contrast ratio for foreground/background color pairs.
- Calculates precise contrast ratio per WCAG relative luminance formula
- Reports AA and AAA compliance for normal and large text
- Accepts hex (
#fff,#ffffff),rgb(r,g,b), and named colors
Details
- Repository
- github.com/rog0x/mcp-a11y-tools
- Package
@rog0x/mcp-a11y-tools- Transport
- STDIO
- Registry
- MCP registry, active