SEO Analyzer

Static SEO analysis for HTML files using cheerio-based parsing. Validates meta tags, social media tags, heading structure, and structured data.

Analysis Workflow

Parse HTML with cheerio
Check Critical Issues (P0):
- Title tag presence and length
- Meta description presence and length
- Single H1 tag
- Canonical URL
Check Important Issues (P1):
- Robots meta directives
- Viewport meta
- Heading hierarchy
- Lang attribute
Check Recommended (P2):
- Open Graph tags
- Twitter Cards
- JSON-LD structured data
- Hreflang tags
Generate Report with issues and recommendations

Usage

Run Analysis Script

# Analyze a single HTML file
bash ${CLAUDE_PLUGIN_ROOT}/skills/seo-analyzer/scripts/run-seo-analyzer.sh path/to/file.html

# Output JSON format
bash ${CLAUDE_PLUGIN_ROOT}/skills/seo-analyzer/scripts/run-seo-analyzer.sh path/to/file.html --json

Direct Node.js Usage

# Install dependencies first
cd ${CLAUDE_PLUGIN_ROOT}/skills/seo-analyzer && npm install

# Run analyzer
node ${CLAUDE_PLUGIN_ROOT}/skills/seo-analyzer/scripts/analyze-seo.js path/to/file.html

Check Items

P0 - Critical (Indexing/Ranking Impact)

Check	Validation	Impact
Title	Exists, 30-60 chars	Search display
Description	Exists, 70-160 chars	Click-through rate
H1	Exactly one	Content hierarchy
Canonical	Exists, valid URL	Duplicate content

P1 - Important (SEO Quality)

Check	Validation	Impact
Robots	No unintended noindex	Indexing
Viewport	Exists	Mobile SEO
Heading order	h1→h2→h3 sequence	Structure
Lang	Exists on html	i18n SEO

P2 - Recommended (Social/Rich Results)

Check	Validation	Impact
og:title	Exists, ≤95 chars	Social sharing
og:description	Exists	Social sharing
og:image	Exists, valid URL	Social sharing
twitter:card	Exists	Twitter display
JSON-LD	Valid schema	Rich results

Output Format

Text Report

# SEO Analysis Report: index.html

## Summary
- Critical: 1
- Important: 2
- Recommended: 3

## Critical Issues (P0)

### 1. Missing Meta Description
**Problem**: No meta description found
**Impact**: Poor click-through rate in search results
**Fix**: Add <meta name="description" content="Your description here">

## Important Issues (P1)
...

JSON Output

{
  "file": "index.html",
  "timestamp": "2024-01-15T10:00:00Z",
  "summary": {
    "critical": 1,
    "important": 2,
    "recommended": 3,
    "passed": 8
  },
  "issues": [
    {
      "severity": "critical",
      "check": "meta-description",
      "message": "Missing meta description",
      "fix": "Add <meta name=\"description\" content=\"...\">"
    }
  ],
  "passed": [
    {
      "check": "title",
      "value": "Page Title - Brand",
      "length": 18
    }
  ]
}

Detection Features

React/SPA Detection

The analyzer detects client-side rendered applications and adjusts confidence:

Presence of #root or #app container
React/Vue/Angular script references
Empty body with JavaScript bundles

When detected, a warning is added that static analysis may not reflect the rendered page.

Framework-Specific Patterns

For JSX/TSX files, the analyzer looks for:

next/head imports (Next.js)
Helmet component (React Helmet)
meta function exports (Remix)

Keyword Analysis

Optional keyword analysis using keyword-analyzer.js:

node ${CLAUDE_PLUGIN_ROOT}/skills/seo-analyzer/scripts/keyword-analyzer.js file.html

Outputs:

Primary keywords detected
Keyword placement (title, h1, description)
Keyword density

Integration with Lookup

For detailed guidance on any issue, reference the seo-lookup skill:

# Look up og:image requirements
cat ${CLAUDE_PLUGIN_ROOT}/skills/seo-lookup/seo-index.json | jq '.["og-tags"]["og:image"]'

# Look up Article schema
cat ${CLAUDE_PLUGIN_ROOT}/skills/seo-lookup/structured-data-index.json | jq '.schemas.Article'

External Validation

After fixing issues, validate with:

seo-analyzer