A technical SEO audit is a review of whether search engines can crawl, render, understand, and index a site reliably. Claude SEO checks crawlability, indexability, security, URLs, mobile behavior, Core Web Vitals, structured data, JavaScript rendering, IndexNow, and AI crawler access.
When you run /seo technical, Claude SEO performs a deep technical analysis across 9 categories that form the foundation of search engine visibility. Each category produces a pass/warn/fail status with a score out of 100, along with specific issues and fixes.
The audit covers everything from basic crawlability (robots.txt, sitemaps) through advanced topics like JavaScript rendering guidance from Google's December 2025 documentation update and IndexNow protocol for faster indexing on Bing, Yandex, and Naver.
What each category covers
Each of the 9 categories produces a pass/warn/fail status and a score. Issues are prioritized into 4 severity levels: Critical (fix immediately), High (fix within 1 week), Medium (fix within 1 month), and Low (backlog).
01
CRAWLABILITY
Robots.txt validation, XML sitemap existence and format, noindex tag detection, crawl depth analysis (important pages within 3 clicks), JavaScript rendering checks, and AI crawler management for 7 crawlers.
02
INDEXABILITY
Canonical tag validation (self-referencing, no noindex conflicts), duplicate content detection, thin content flagging, pagination patterns, hreflang for multi-language sites, and index bloat identification.
03
SECURITY
HTTPS enforcement, valid SSL certificate, no mixed content. Security headers: Content-Security-Policy, Strict-Transport-Security with preload eligibility, X-Frame-Options, X-Content-Type-Options, Referrer-Policy.
04
URL STRUCTURE
Clean descriptive URLs, logical folder hierarchy, redirect chain detection (max 1 hop), URL length flags over 100 characters, and consistent trailing slash usage across the site.
05
MOBILE
Viewport meta tag, responsive CSS, touch targets (minimum 48x48px with 8px spacing), base font size (minimum 16px), no horizontal scroll. Mobile-first indexing is 100% complete since July 2024.
06
CORE WEB VITALS
LCP under 2.5 seconds, INP under 200ms (replaced FID March 2024), CLS under 0.1. Evaluation uses 75th percentile of real user data. Uses PageSpeed Insights API or CrUX data if available.
07
STRUCTURED DATA
Detects JSON-LD (preferred), Microdata, and RDFa. Validates against Google's supported types. Cross-references the seo-schema skill for full analysis.
08
JS RENDERING
Checks if content is visible in initial HTML vs requires JavaScript. Identifies CSR vs SSR, flags SPA frameworks. Per Google Dec 2025 guidance: canonical, meta robots, and structured data should be in server-rendered HTML.
09
INDEXNOW
Checks if the site supports the IndexNow protocol for faster indexing on Bing, Yandex, and Naver. Supported by search engines other than Google. Recommends implementation for non-Google engine visibility.
// SCORING
How are technical issues categorized?
Each category produces its own score out of 100, with a pass/warn/fail status. The overall Technical SEO Score is computed from all 9 categories. Issues are grouped by severity for clear prioritization.
CRAWLABILITY
/100
INDEXABILITY
/100
SECURITY
/100
URL STRUCTURE
/100
MOBILE
/100
CORE WEB VITALS
/100
STRUCTURED DATA
/100
JS RENDERING
/100
INDEXNOW
/100
Issue severity levels
Severity
Timeline
Critical
Fix immediately
High
Fix within 1 week
Medium
Fix within 1 month
Low
Backlog
AI crawler management
The crawlability check includes 7 AI crawlers in robots.txt: GPTBot (OpenAI), ChatGPT-User (OpenAI), ClaudeBot (Anthropic), PerplexityBot (Perplexity), Bytespider (ByteDance), Google-Extended (Gemini training, not search), and CCBot (Common Crawl). Blocking Google-Extended does not affect Google Search indexing or AI Overviews.
The audit checks all 9 categories and produces a scored breakdown with prioritized issues. Every finding includes a specific fix recommendation.
Core Web Vitals targets
Metric
Good
Needs improvement
Poor
LCP (Largest Contentful Paint)
Under 2.5s
2.5s - 4.0s
Over 4.0s
INP (Interaction to Next Paint)
Under 200ms
200ms - 500ms
Over 500ms
CLS (Cumulative Layout Shift)
Under 0.1
0.1 - 0.25
Over 0.25
// FAQ
QUESTIONS ABOUT TECHNICAL SEO
The 9 categories are: Crawlability (robots.txt, XML sitemap, noindex tags, crawl depth), Indexability (canonical tags, duplicates, hreflang), Security (HTTPS, CSP, HSTS, X-Frame-Options), URL Structure (clean URLs, redirects, trailing slashes), Mobile Optimization (responsive design, touch targets, font sizes), Core Web Vitals (LCP under 2.5s, INP under 200ms, CLS under 0.1), Structured Data (JSON-LD detection and validation), JavaScript Rendering (SSR vs CSR, SPA framework detection), and IndexNow Protocol (Bing, Yandex, Naver support).
Yes. The technical audit checks robots.txt for 7 known AI crawlers: GPTBot (OpenAI), ChatGPT-User (OpenAI), ClaudeBot (Anthropic), PerplexityBot (Perplexity), Bytespider (ByteDance), Google-Extended (Gemini training), and CCBot (Common Crawl). It reports which are allowed or blocked and recommends a strategy based on your AI visibility goals.
The audit measures LCP (Largest Contentful Paint, target under 2.5 seconds), INP (Interaction to Next Paint, target under 200ms), and CLS (Cumulative Layout Shift, target under 0.1). INP replaced FID on March 12, 2024. FID was fully removed from all Chrome tools on September 9, 2024. Evaluation uses the 75th percentile of real user data.
The audit checks if content is visible in the initial HTML or requires JavaScript execution. It identifies client-side rendered (CSR) versus server-side rendered (SSR) content, flags SPA frameworks (React, Vue, Angular) that may cause indexing issues, and follows Google's December 2025 guidance that canonical tags, meta robots, and structured data should be in the initial server-rendered HTML.
The audit checks for Content-Security-Policy (CSP), Strict-Transport-Security (HSTS) with preload eligibility, X-Frame-Options, X-Content-Type-Options, and Referrer-Policy. It also verifies HTTPS enforcement, valid SSL certificates, and absence of mixed content.
// RELATED SKILLS
EXPLORE MORE
FULL SITE AUDIT
The full-site audit delegates to up to 15 specialists. Technical SEO is one of 7 weighted scoring categories in the combined report.
