Technical SEO audit across 9 categories: crawlability, indexability, security, URL structure, mobile, Core Web Vitals, structured data, JavaScript rendering, and IndexNow protocol. Use when user says "technical SEO", "crawl issues", "robots.txt", "Core Web Vitals", "site speed", or "security headers".
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
A direct command skips the review prompt. Inspect the source before running it.
Technical SEO audit across 9 categories: crawlability, indexability, security, URL structure, mobile, Core Web Vitals, structured data, JavaScript rendering, and IndexNow protocol. Use when user says "technical SEO", "crawl issues", "robots.txt", "Core Web Vitals", "site speed", or "security headers".
Before gathering, check .seo-cache/ for reusable context from related SEO skills.
Reference: ../seo/references/shared-data-cache.md for schemas and dependency map.
Check these cache files when present:
.seo-cache/site-meta.json for domain, business type, industry, and crawl context
.seo-cache/audit-scores.json for prior full-audit priorities
.seo-cache/pages/{url-slug}/page-analysis.json for page-level context when a URL is provided
If found: parse and use clearly valid fields (note "Using cached [X] from [date]")
If missing, corrupt, or irrelevant: continue with fresh evidence
If the user says "refresh" or "re-run": ignore cache reads and overwrite on write
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
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
pass/warn/fail
XX/100
Indexability
pass/warn/fail
XX/100
Security
pass/warn/fail
XX/100
URL Structure
pass/warn/fail
XX/100
Mobile
pass/warn/fail
XX/100
Core Web Vitals
pass/warn/fail
XX/100
Structured Data
pass/warn/fail
XX/100
JS Rendering
pass/warn/fail
XX/100
IndexNow
pass/warn/fail
XX/100
Critical Issues (fix immediately)
High Priority (fix within 1 week)
Medium Priority (fix within 1 month)
Low Priority (backlog)
DataForSEO Integration (Optional)
If DataForSEO MCP tools are available, use on_page_instant_pages for real page analysis (status codes, page timing, broken links, on-page checks), on_page_lighthouse for Lighthouse audits (performance, accessibility, SEO scores), and domain_analytics_technologies_domain_technologies for technology stack detection.
Google API Integration (Optional)
If Google API credentials are configured, use python scripts/pagespeed_check.py <url> --json for real PSI + CrUX field data (replaces lab-only CWV estimates), python scripts/crux_history.py <url> --json for 25-week CWV trends, and python scripts/gsc_inspect.py <url> --json for real indexation status per URL.
Error Handling
Scenario
Action
URL unreachable
Report connection error with status code. Suggest verifying URL, checking DNS resolution, and confirming the site is publicly accessible.
robots.txt not found
Note that no robots.txt was detected at the root domain. Recommend creating one with appropriate directives. Continue audit on remaining categories.
HTTPS not configured
Flag as a critical issue. Report whether HTTP is served without redirect, mixed content exists, or SSL certificate is missing/expired.
Core Web Vitals data unavailable
Note that CrUX data is not available (common for low-traffic sites). Suggest using Lighthouse lab data as a proxy and recommend increasing traffic before re-testing.
Write to shared data cache
After completing all work, write a concise JSON summary to .seo-cache/ when the workflow produced durable findings.
Use the schemas and naming rules in ../seo/references/shared-data-cache.md; include at least cache_type, analyzed_at, source URL/domain, key findings, issues, recommendations, and tool limitations. Add .seo-cache/ to .gitignore if it is missing.
