TECHNICAL SEO AUDITING — OPERATIONAL SKILL
This skill contains actionable, production-ready systems for performing comprehensive technical SEO audits and delivering prioritized optimization recommendations for traditional search engines (Google, Bing).
Use this skill when the user asks for:
- Technical SEO audits (full or targeted)
- Core Web Vitals optimization (LCP, INP, CLS)
- Crawlability and indexation issues
- Structured data/Schema.org implementation
- Mobile-first optimization
- Site speed and performance fixes
- Internal linking architecture
- Duplicate content and canonical handling
- International SEO (hreflang)
- Security and HTTPS configuration
Quick Reference
| Task | Resource/Template | Location | When to Use |
|---|---|---|---|
| Auditing | |||
| Full Technical Audit | 10-Point Checklist | templates/audits/full-technical-audit.md |
Comprehensive site-wide audit |
| Quick Audit | Abbreviated Checklist | templates/audits/quick-audit-checklist.md |
Fast issue identification |
| Priority Matrix | Impact vs Effort | templates/priority/impact-effort-matrix.md |
Prioritize audit findings |
| Core Web Vitals | |||
| CWV Deep Dive | CWV Guide | resources/core-web-vitals-guide.md |
LCP, INP, CLS optimization |
| CWV Report | Report Template | templates/cwv/core-web-vitals-report.md |
Document CWV findings |
| Crawlability | |||
| Indexation Issues | Crawlability Guide | resources/crawlability-indexing.md |
Robots.txt, sitemaps, GSC issues |
| Performance | |||
| Site Speed | Speed Guide | resources/site-speed-optimization.md |
TTFB, render-blocking, images |
| Technical Setup | |||
| Mobile Optimization | Mobile Guide | resources/mobile-seo-guide.md |
Responsive, viewport, mobile-first |
| Structured Data | Schema Guide | resources/structured-data-guide.md |
JSON-LD, rich snippets |
| Schema Report | Validation Template | templates/schema/schema-validation-report.md |
Document schema findings |
| Security/HTTPS | Security Guide | resources/security-https-guide.md |
HTTPS, HSTS, headers |
| Architecture | |||
| Internal Linking | Link Strategy | resources/internal-linking-strategy.md |
Link equity, orphan pages |
| Duplicate Content | Canonical Guide | resources/duplicate-content-handling.md |
Canonicals, pagination |
| International SEO | Hreflang Guide | resources/internationalization-hreflang.md |
Multi-language/region sites |
10-Point Audit Framework
Every technical SEO audit follows this systematic checklist:
| # | Area | Key Metrics | Weight |
|---|---|---|---|
| 1 | Crawlability | robots.txt status, sitemap coverage, crawl budget | High |
| 2 | Core Web Vitals | LCP <2.5s, INP <200ms, CLS <0.1 | High |
| 3 | Site Speed | TTFB <800ms, FCP <1.8s, Speed Index | High |
| 4 | Mobile | Mobile-friendly score, viewport, touch targets | High |
| 5 | Security | HTTPS, mixed content, HSTS, headers | Medium |
| 6 | Structured Data | Schema validity, rich snippet eligibility | Medium |
| 7 | On-Page | Meta tags, heading hierarchy, keyword signals | Medium |
| 8 | Architecture | Internal links, URL structure, canonicals | High |
| 9 | Duplicate Content | Canonical implementation, pagination | Medium |
| 10 | Internationalization | Hreflang (if applicable), geo-targeting | Low |
Scoring: Rate each area 0-10, calculate weighted average for overall Technical Health Score.
Decision Trees
### Audit Type Selection
Full site audit needed
└─ Use templates/audits/full-technical-audit.md
Quick issue check
└─ Use templates/audits/quick-audit-checklist.md
CWV-only deep dive
└─ Use templates/cwv/core-web-vitals-report.md
Schema validation only
└─ Use templates/schema/schema-validation-report.md
### Core Web Vitals Failing
LCP >2.5s
└─ Preload LCP element, optimize images, add CDN
└─ See resources/core-web-vitals-guide.md
INP >200ms
└─ Reduce JavaScript, optimize event handlers
└─ See resources/core-web-vitals-guide.md
CLS >0.1
└─ Add dimensions to images/ads, avoid layout shifts
└─ See resources/core-web-vitals-guide.md
### Indexation Issues
Pages not indexed
└─ Check robots.txt blocking
└─ Verify sitemap inclusion
└─ Check canonical tags
└─ See resources/crawlability-indexing.md
Crawl budget problems
└─ Remove low-value pages from crawl
└─ Fix redirect chains
└─ Optimize pagination
└─ See resources/crawlability-indexing.md
### Mobile Issues
Mobile-unfriendly
└─ Check viewport meta tag
└─ Verify responsive CSS
└─ Test touch target sizes
└─ See resources/mobile-seo-guide.md
### Security Issues
Mixed content warnings
└─ Update all HTTP resources to HTTPS
└─ See resources/security-https-guide.md
SSL/TLS issues
└─ Run SSL Labs test
└─ See resources/security-https-guide.md
Navigation
Core Resources
- resources/core-web-vitals-guide.md - LCP, INP, CLS thresholds and optimization
- resources/crawlability-indexing.md - Robots.txt, sitemaps, GSC, indexation
- resources/site-speed-optimization.md - TTFB, render-blocking, image optimization
- resources/mobile-seo-guide.md - Mobile-first indexing, responsive design
- resources/structured-data-guide.md - Schema.org, JSON-LD, rich snippets
- resources/security-https-guide.md - HTTPS, HSTS, security headers
- resources/internal-linking-strategy.md - Link architecture, orphan pages
- resources/duplicate-content-handling.md - Canonicals, pagination, parameters
- resources/internationalization-hreflang.md - Hreflang, geo-targeting
Templates
Audits
- templates/audits/full-technical-audit.md - Complete 10-point audit checklist
- templates/audits/quick-audit-checklist.md - Fast abbreviated audit
Core Web Vitals
- templates/cwv/core-web-vitals-report.md - CWV-specific audit report
Structured Data
- templates/schema/schema-validation-report.md - Schema audit report
Prioritization
- templates/priority/impact-effort-matrix.md - Issue prioritization matrix
Related Skills
Marketing & SEO
- ../marketing-ai-search-optimization/SKILL.md - Search visibility beyond classic SERPs (complements technical SEO)
- ../marketing-social-media/SKILL.md - Social media marketing and content distribution
Technical Implementation
- ../software-frontend/SKILL.md - Frontend performance optimization, SSR
- ../software-backend/SKILL.md - Server-side optimization, API performance
- ../software-security-appsec/SKILL.md - Security hardening, HTTPS implementation
Quality & Performance
- ../qa-observability/SKILL.md - Performance monitoring, observability
- ../ops-devops-platform/SKILL.md - CDN setup, infrastructure optimization
Key Differentiators
Audit Output Format:
- Critical Issues - Fix immediately (high impact)
- Important Optimizations - Fix soon (medium impact)
- Recommended Enhancements - Nice to have
Each finding includes:
- What's wrong and why it matters
- Step-by-step fix instructions
- Expected outcome
- Validation method
External Resources
See data/sources.json for 46 primary sources across:
- Google Search Central, web.dev, and Chrome developer docs (CWV, Lighthouse, CrUX)
- Bing Webmaster Guidelines and diagnostic tooling
- Crawl/index/render fundamentals (robots, sitemaps, canonicals, JS SEO)
- Structured data eligibility and validation tooling
- Optional automation references (Search Console API, CrUX API, Lighthouse CI)
Getting Started
Quick audit (15 minutes):
- Run PageSpeed Insights on key pages
- Check robots.txt and sitemap.xml accessibility
- Validate structured data with Rich Results Test
- Review GSC Coverage report for indexation issues
- Use templates/audits/quick-audit-checklist.md
Full audit (2-4 hours):
- Use templates/audits/full-technical-audit.md
- Work through all 10 audit areas systematically
- Score each area 0-10
- Prioritize findings with templates/priority/impact-effort-matrix.md
- Document fixes with validation steps
Ongoing monitoring:
- Set up GSC alerts for indexation issues
- Monitor Core Web Vitals in CrUX
- Schedule quarterly audits
- Track improvements against baseline
Core: SEO Testing & Monitoring
Testing Framework
| Test Type | When | Tools | Goal |
|---|---|---|---|
| Pre-launch | Before deployment | Staging crawl, Lighthouse CI | Catch issues before they affect live site |
| SEO split tests | When optimizing | Edge routing, feature flags, server-side experiments | Validate changes before full rollout |
| Regression testing | After deployments | Screaming Frog, Sitebulb | Ensure no new issues introduced |
| CWV monitoring | Continuous | CrUX, PageSpeed API, WebPageTest | Track performance over time |
Monitoring Checklist
| Signal | Frequency | Tool | Alert Threshold |
|---|---|---|---|
| Indexation status | Daily | GSC Coverage | >5% drop |
| CWV scores | Daily | CrUX/PSI | Any metric fails threshold |
| Crawl errors | Daily | GSC | Any new 4xx/5xx |
| Sitemap health | Weekly | GSC | Submitted ≠ Indexed |
| Schema validity | Weekly | Rich Results Test | Any errors |
| Security issues | Daily | GSC Security Issues | Any alerts |
Do (Testing)
- Set up automated Lighthouse CI in your deployment pipeline
- Use GSC API to monitor indexation programmatically
- Test staging environments with noindex before launch
- Track CWV in CrUX (field data) not just lab data
- Create baseline measurements before optimization
Avoid (Testing)
- Testing only on fast dev machines (test on throttled mobile)
- Ignoring field data (CrUX) in favor of lab data (Lighthouse)
- Making multiple changes simultaneously (can't isolate impact)
- Deploying without crawling staging first
Success Criteria
A successful technical SEO audit delivers a prioritized list of issues with clear fix instructions and validation methods that measurably improve search visibility and Core Web Vitals scores.
Optional: AI / Automation
Note: Core technical SEO fundamentals above work without AI tools. This section covers optional automation capabilities.
Automated Auditing Tools
| Tool | Automation Level | Best For |
|---|---|---|
| Screaming Frog | Crawl + export | Comprehensive site audits |
| Sitebulb | Crawl + prioritized insights | Visual issue prioritization |
| Semrush Site Audit | Automated crawls + alerts | Continuous monitoring |
| Ahrefs Site Audit | Automated crawls | Technical + backlink combined |
| ContentKing | Real-time monitoring | Enterprise with frequent changes |
| Lumar (DeepCrawl) | Enterprise crawling | Large sites, JavaScript-heavy |
Log Analysis Automation
| Tool | Use Case |
|---|---|
| Screaming Frog Log Analyzer | Googlebot crawl patterns |
| OnCrawl | Log + crawl correlation |
| JetOctopus | Large-scale log analysis |
| BigQuery + GSC API | Custom analysis pipelines |
AI-Assisted Analysis
| Use Case | Approach | Consideration |
|---|---|---|
| Issue prioritization | ML models rank by impact | Validate with domain knowledge |
| Anomaly detection | Automated traffic/ranking drops | Set appropriate thresholds |
| Content gap analysis | NLP-based competitor analysis | Combine with manual review |
| Schema generation | LLM-generated JSON-LD | Always validate output |
Do (AI/Automation)
- Automate crawling on a schedule (weekly minimum)
- Use alerts for critical issues (500 errors, robots.txt changes)
- Combine automated findings with manual analysis
- Version control robots.txt and critical SEO files
Avoid (AI/Automation)
- Trusting automated recommendations without validation
- Over-relying on tools without understanding fundamentals
- Auto-implementing schema without testing
- Ignoring false positives (tools over-report)
Collaboration Notes
With Product
- Site redesigns: SEO requirements in early planning, not post-launch
- URL changes: Redirect mapping before launch
- New features: Consider indexability and crawlability impact
- Page deprecation: Proper 301/410 handling
With Engineering
- Deployment pipeline: Add Lighthouse CI, crawl staging pre-launch
- Performance budgets: Set CWV thresholds in CI
- Server config: robots.txt, redirects, canonical implementation
- JavaScript: SSR/SSG for critical content, hydration impact
- CDN setup: Cache headers, edge optimization
With Design
- Image optimization: WebP/AVIF formats, responsive images
- Layout stability: Reserve space for dynamic elements (CLS)
- Above-the-fold: Prioritize LCP element rendering
- Fonts: Font loading strategy (font-display: swap)
Anti-Patterns
| Anti-Pattern | Why It Fails | Instead |
|---|---|---|
| Audit without action | Findings sit in a spreadsheet | Assign owners, set deadlines, track progress |
| Fix everything at once | Can't measure what worked | Batch by priority, deploy incrementally |
| Ignore mobile | 60%+ of traffic is mobile, mobile-first indexing | Test and optimize mobile-first |
| Over-optimize CWV | Diminishing returns past "good" threshold | Focus on user experience, not perfect scores |
| Block crawlers "for protection" | Invisible to search | Allow crawlers, rate limit if needed |
| Dynamic rendering as first choice | Complexity, maintenance cost | Prefer SSR/SSG; dynamic rendering as last resort |
| Trust lab data only | Doesn't reflect real user experience | Use CrUX (field data) as source of truth |
| One-time audit | SEO degrades over time | Continuous monitoring, quarterly deep audits |