| name | seo-technical |
| description | Technical SEO audit across 8 categories: crawlability, indexability, security, URL structure, mobile, Core Web Vitals, structured data, and JavaScript rendering. Use when user says "technical SEO", "crawl issues", "robots.txt", "Core Web Vitals", "site speed", or "security headers".
|
Technical SEO Audit
Categories
1. Crawlability
- robots.txt: exists, valid, not blocking important resources
- XML sitemap: exists, referenced in robots.txt, valid format
- Noindex tags: intentional vs accidental
- Crawl depth: important pages within 3 clicks of homepage
- JavaScript rendering: check if critical content requires JS execution
- Crawl budget: for large sites (>10k pages), efficiency matters
AI Crawler Management
As of 2025-2026, AI companies actively crawl the web to train models and power AI search. Managing these crawlers via robots.txt is a critical technical SEO consideration.
Known AI crawlers:
| Crawler | Company | robots.txt token | Purpose |
|---|
| GPTBot | OpenAI | GPTBot | Model training |
| ChatGPT-User | OpenAI | ChatGPT-User | Real-time browsing |
| ClaudeBot | Anthropic | ClaudeBot | Model training |
| PerplexityBot | Perplexity | PerplexityBot | Search index + training |
| Bytespider | ByteDance | Bytespider | Model training |
| Google-Extended | Google | Google-Extended | Gemini training (NOT search) |
| CCBot | Common Crawl | CCBot | Open dataset |
Key distinctions:
- Blocking
Google-Extended prevents Gemini training use but does NOT affect Google Search indexing or AI Overviews (those use Googlebot)
- Blocking
GPTBot prevents OpenAI training but does NOT prevent ChatGPT from citing your content via browsing (ChatGPT-User)
- ~3-5% of websites now use AI-specific robots.txt rules
Example — selective AI crawler blocking:
# Allow search indexing, block AI training crawlers
User-agent: GPTBot
Disallow: /
User-agent: Google-Extended
Disallow: /
User-agent: Bytespider
Disallow: /
# Allow all other crawlers (including Googlebot for search)
User-agent: *
Allow: /
Recommendation: Consider your AI visibility strategy before blocking. Being cited by AI systems drives brand awareness and referral traffic. Cross-reference the seo-geo skill for full AI visibility optimization.
2. Indexability
- Canonical tags: self-referencing, no conflicts with noindex
- Duplicate content: near-duplicates, parameter URLs, www vs non-www
- Thin content: pages below minimum word counts per type
- Pagination: rel=next/prev or load-more pattern
- Hreflang: correct for multi-language/multi-region sites
- Index bloat: unnecessary pages consuming crawl budget
3. Security
- HTTPS: enforced, valid SSL certificate, no mixed content
- Security headers:
- Content-Security-Policy (CSP)
- Strict-Transport-Security (HSTS)
- X-Frame-Options
- X-Content-Type-Options
- Referrer-Policy
- HSTS preload: check preload list inclusion for high-security sites
4. URL Structure
- Clean URLs: descriptive, hyphenated, no query parameters for content
- Hierarchy: logical folder structure reflecting site architecture
- Redirects: no chains (max 1 hop), 301 for permanent moves
- URL length: flag >100 characters
- Trailing slashes: consistent usage
5. Mobile Optimization
- Responsive design: viewport meta tag, responsive CSS
- Touch targets: minimum 48x48px with 8px spacing
- Font size: minimum 16px base
- No horizontal scroll
- Mobile-first indexing: Google indexes mobile version. Mobile-first indexing is 100% complete as of July 5, 2024. Google now crawls and indexes ALL websites exclusively with the mobile Googlebot user-agent.
6. Core Web Vitals
- LCP (Largest Contentful Paint): target <2.5s
- INP (Interaction to Next Paint): target <200ms
- INP replaced FID on March 12, 2024. FID was fully removed from all Chrome tools (CrUX API, PageSpeed Insights, Lighthouse) on September 9, 2024. Do NOT reference FID anywhere.
- CLS (Cumulative Layout Shift): target <0.1
- Evaluation uses 75th percentile of real user data
- Use PageSpeed Insights API or CrUX data if MCP available
7. Structured Data
- Detection: JSON-LD (preferred), Microdata, RDFa
- Validation against Google's supported types
- See seo-schema skill for full analysis
8. JavaScript Rendering
- Check if content visible in initial HTML vs requires JS
- Identify client-side rendered (CSR) vs server-side rendered (SSR)
- Flag SPA frameworks (React, Vue, Angular) that may cause indexing issues
- Verify dynamic rendering setup if applicable
JavaScript SEO — Canonical & Indexing Guidance (December 2025)
Google updated its JavaScript SEO documentation in December 2025 with critical clarifications:
- Canonical conflicts: If a canonical tag in raw HTML differs from one injected by JavaScript, Google may use EITHER one. Ensure canonical tags are identical between server-rendered HTML and JS-rendered output.
- noindex with JavaScript: If raw HTML contains
<meta name="robots" content="noindex"> but JavaScript removes it, Google MAY still honor the noindex from raw HTML. Serve correct robots directives in the initial HTML response.
- Non-200 status codes: Google does NOT render JavaScript on pages returning non-200 HTTP status codes. Any content or meta tags injected via JS on error pages will be invisible to Googlebot.
- Structured data in JavaScript: Product, Article, and other structured data injected via JS may face delayed processing. For time-sensitive structured data (especially e-commerce Product markup), include it in the initial server-rendered HTML.
Best practice: Serve critical SEO elements (canonical, meta robots, structured data, title, meta description) in the initial server-rendered HTML rather than relying on JavaScript injection.
9. IndexNow Protocol
- Check if site supports IndexNow for Bing, Yandex, Naver
- Supported by search engines other than Google
- Recommend implementation for faster indexing on non-Google engines
Output
Technical Score: XX/100
Category Breakdown
| Category | Status | Score |
|---|
| Crawlability | ✅/⚠️/❌ | XX/100 |
| Indexability | ✅/⚠️/❌ | XX/100 |
| Security | ✅/⚠️/❌ | XX/100 |
| URL Structure | ✅/⚠️/❌ | XX/100 |
| Mobile | ✅/⚠️/❌ | XX/100 |
| Core Web Vitals | ✅/⚠️/❌ | XX/100 |
| Structured Data | ✅/⚠️/❌ | XX/100 |
| JS Rendering | ✅/⚠️/❌ | XX/100 |
Critical Issues (fix immediately)
High Priority (fix within 1 week)
Medium Priority (fix within 1 month)
Low Priority (backlog)
