Perform Technical SEO Audits

This skill runs a technical SEO audit across nine categories, producing a scored output. Crawlability covers robots.txt validity, XML sitemap presence, intentional versus accidental noindex tags, crawl depth (important pages within 3 clicks of the homepage), JavaScript rendering dependence, and crawl-budget efficiency for sites over 10k pages. It includes dedicated AI crawler management guidance: a reference table of known AI crawlers (GPTBot/OpenAI for model training, ChatGPT-User/OpenAI for real-time browsing, ClaudeBot/Anthropic for training, PerplexityBot for search index plus training, Bytespider/ByteDance for training, Google-Extended/Google for Gemini training only, and CCBot/Common Crawl for its open dataset), noting that blocking Google-Extended does not affect Google Search indexing or AI Overviews, and blocking GPTBot does not stop ChatGPT from citing content via ChatGPT-User browsing. Roughly 3-5% of sites now use AI-specific robots.txt rules.

Indexability checks canonical tags, duplicate and thin content, pagination markup, hreflang correctness, and index bloat. Security checks HTTPS enforcement, CSP/HSTS/X-Frame-Options/X-Content-Type-Options/Referrer-Policy headers, and HSTS preload-list inclusion for high-security sites. URL structure checks clean, hyphenated URLs, logical folder hierarchy, redirect chains capped at one hop, URL length over 100 characters, and trailing-slash consistency. Mobile optimization checks responsive design, 48x48px touch targets with 8px spacing, minimum 16px base font, no horizontal scroll, and notes that mobile-first indexing was 100% complete as of July 5, 2024, so Google now crawls and indexes all sites exclusively with the mobile Googlebot user agent.

Core Web Vitals targets LCP under 2.5s, INP under 200ms, and CLS under 0.1, evaluated at the 75th percentile of real user data; INP replaced FID on March 12, 2024, and FID was fully removed from CrUX API, PageSpeed Insights, and Lighthouse on September 9, 2024. Structured data detection covers JSON-LD, Microdata, and RDFa. JavaScript rendering checks distinguish content visible in initial HTML from content requiring JS execution and flag CSR frameworks (React, Vue, Angular) that may cause indexing issues. A December 2025 JavaScript SEO update is incorporated: Google may use either a raw-HTML or JS-injected canonical tag when they conflict; Google may still honor a noindex present in raw HTML even if JavaScript removes it; Google does not render JavaScript on non-200 status-code pages; and structured data injected via JS (especially e-commerce Product markup) can face delayed processing, so critical SEO elements should be served in the initial server-rendered HTML. IndexNow protocol support for Bing, Yandex, and Naver is checked as a faster-indexing option for non-Google engines.

Use it for a technical SEO review focused on crawlability, indexability, performance, or rendering - auditing robots.txt, canonicalization, JavaScript SEO, Core Web Vitals, or AI crawler access - when the task is infrastructure- and implementation-oriented rather than content-focused.

Outputs a technical score out of 100 with a per-category breakdown (crawlability, indexability, security, URL structure, mobile, Core Web Vitals, structured data, JS rendering, IndexNow) each marked pass/warn/fail, plus issues grouped by critical, high, medium, and low priority. If DataForSEO MCP tools are available, it uses on_page_instant_pages for status codes, timing, and broken links, on_page_lighthouse for Lighthouse audits, and domain_analytics_technologies_domain_technologies for tech-stack detection. Handles unreachable URLs, missing robots.txt, missing HTTPS, and unavailable Core Web Vitals data (falling back to Lighthouse lab data) as defined error cases.

Cross-references the seo-geo skill for full AI visibility optimization strategy and the seo-schema skill for full structured-data analysis.

SEO practitioners and developers running implementation-level technical audits who need current, dated guidance on AI crawler handling, Core Web Vitals metric changes, and December-2025 JavaScript rendering rules rather than generic content-SEO advice.