Technical Seo

---
context: fork
name: technical-seo
description: "Audits and optimizes technical SEO covering site structure, crawlability, Core Web Vitals, schema markup, and indexation with scoring checklists. Use when user asks about technical SEO audit, site speed, Core Web Vitals, schema markup, crawlability, robots.txt, sitemap, page speed, 테크니컬 SEO, 사이트 속도, or 크롤링."
platforms: [claude-code, gemini-cli, codex-cli, cursor]
level: 3
triggers:
  - "technical SEO"
  - "site speed"
  - "Core Web Vitals"
  - "crawlability"
  - "schema markup"
  - "sitemap"
agents:
  - "seo-specialist"
tokens: "~4K"
category: "marketing"
---

# Technical SEO

## When This Skill Applies
- Auditing website technical SEO health
- Optimizing Core Web Vitals and page speed
- Implementing and validating schema markup
- Fixing crawlability and indexation issues
- Ensuring mobile-friendliness and site structure

## Core Guidance

### 1. Technical SEO Audit Process
```
Crawl Site -> Check Indexation -> Audit Page Speed -> Validate Schema -> Review Mobile -> Analyze Links -> Score Health -> Prioritize Fixes
```

### 2. Technical SEO Scoring

| Category | Weight | Elements |
|----------|--------|----------|
| Crawlability | 20% | Robots.txt, sitemap, crawl errors, URL structure |
| Indexation | 15% | Index coverage, canonical tags, noindex directives |
| Page Speed | 20% | Core Web Vitals (LCP, FID, CLS), TTFB, TBT |
| Mobile | 15% | Responsive design, mobile usability, viewport |
| Structure | 15% | Heading hierarchy, internal links, breadcrumbs |
| Schema | 10% | Structured data, rich snippet eligibility |
| Security | 5% | HTTPS, mixed content, security headers |

### 3. Core Web Vitals Thresholds

| Metric | Good | Needs Improvement | Poor |
|--------|------|-------------------|------|
| LCP (Largest Contentful Paint) | <2.5s | 2.5-4.0s | >4.0s |
| INP (Interaction to Next Paint) | <200ms | 200-500ms | >500ms |
| CLS (Cumulative Layout Shift) | <0.1 | 0.1-0.25 | >0.25 |

**Optimization Priorities**:
- LCP: Optimize images, preload critical resources, reduce server response time
- INP: Minimize JavaScript execution, defer non-critical scripts
- CLS: Set explicit dimensions on images/embeds, avoid dynamic content injection

### 4. Schema Markup Types

| Schema Type | Use Case | Rich Result |
|-------------|----------|-------------|
| Article | Blog posts, news | Article snippet |
| FAQ | FAQ pages | Expandable FAQ |
| HowTo | Tutorial pages | Step-by-step snippet |
| Product | Product pages | Price, availability, reviews |
| Organization | About page | Knowledge panel |
| BreadcrumbList | All pages | Breadcrumb trail |
| LocalBusiness | Local businesses | Local pack, map |
| Review | Review pages | Star ratings |

### 5. Crawlability Checklist

- [ ] robots.txt allows critical pages, blocks low-value pages
- [ ] XML sitemap present, updated, submitted to Search Console
- [ ] No orphan pages (all pages linked from at least one other page)
- [ ] Crawl depth <4 clicks from homepage
- [ ] No redirect chains (>2 hops)
- [ ] No redirect loops
- [ ] 4xx/5xx errors identified and fixed
- [ ] URL structure is clean, descriptive, hyphenated
- [ ] Canonical tags on all pages
- [ ] Pagination handled (rel=next/prev or canonical to all-page)

### 6. Page Speed Optimization

| Category | Quick Wins | Advanced |
|----------|-----------|---------|
| Images | Compress, WebP, lazy load | CDN, responsive images, AVIF |
| CSS | Inline critical CSS, defer non-critical | Purge unused CSS, minify |
| JavaScript | Defer/async non-critical | Code splitting, tree shaking |
| Server | Enable compression (gzip/brotli) | CDN, edge caching, HTTP/3 |
| Fonts | Font-display: swap, preload | Subset fonts, variable fonts |

### 7. Internal Linking Best Practices

| Principle | Rule | Benefit |
|-----------|------|---------|
| Relevance | Link to topically related pages | PageRank flow, user experience |
| Anchor text | Descriptive, keyword-rich (natural) | Context signal for search engines |
| Depth | Important pages within 3 clicks | Crawlability, authority distribution |
| Distribution | Spread links across site, not concentrated | Even authority distribution |
| Freshness | Update old content with links to new | Recrawl signals, discoverability |

### 8. Audit Report Scoring

```
Score /100 = Sum of category scores:
  Crawlability (20):  [score] issues found
  Indexation (15):     [score] issues found
  Page Speed (20):     [score] CWV status
  Mobile (15):         [score] usability issues
  Structure (15):      [score] hierarchy issues
  Schema (10):         [score] markup coverage
  Security (5):        [score] HTTPS/headers
```

## Output Format
```
TECHNICAL SEO AUDIT
===================
Domain:     [domain]
Score:      [/100]
Pages:      [crawled count]

CATEGORY SCORES
---------------
Category        | Score | Issues | Priority
----------------|-------|--------|----------
Crawlability    | [/20] | [n]    | [P1-P3]
Indexation      | [/15] | [n]    | [P1-P3]
Page Speed      | [/20] | [n]    | [P1-P3]
Mobile          | [/15] | [n]    | [P1-P3]
Structure       | [/15] | [n]    | [P1-P3]
Schema          | [/10] | [n]    | [P1-P3]
Security        | [/5]  | [n]    | [P1-P3]

CRITICAL ISSUES
---------------
[Issue]: [description] -> [fix recommendation]

RECOMMENDATIONS
---------------
Priority | Category | Action              | Impact
---------|----------|---------------------|--------
P1       | [cat]    | [specific action]   | [expected improvement]
```

## Quick Reference

**CWV Thresholds**: LCP <2.5s, INP <200ms, CLS <0.1
**Crawl Depth**: Target <4 clicks from homepage
**Schema Priority**: BreadcrumbList, FAQ, Article, Product
**Score Formula**: 7 categories weighted to 100 points

---

## References

- See `${CLAUDE_SKILL_DIR}/references/core-web-vitals.md` for Core Web Vitals optimization guide
- See `${CLAUDE_SKILL_DIR}/references/audit-scoring-matrix.md` for technical SEO audit scoring matrix
- See `${CLAUDE_SKILL_DIR}/references/schema-markup-types.md` for schema markup types reference