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.
The command produces local diagnostics while keeping field data, lab tests, HTML indicators, and experimental checks separate.
OUTCOME
A prioritized technical diagnostic across the documented crawl, render, mobile, security, schema, and performance categories.
REQUIRED INPUT
One reachable site supplied to /seo technical <url>.
READINESS
Rendering may need a compatible browser. CrUX needs sufficient samples. Optional APIs need credentials, quotas, and current access.
LOCAL OUTPUT
Category findings, evidence, limitations, and prioritized fixes, with lab and field measurements labeled separately.
SIDE EFFECTS
Fetches site resources, can call approved providers, and writes local diagnostics. It does not edit robots.txt, code, or production settings.
COST + APPROVAL
Estimate and approve optional paid calls. Robots rules, IndexNow actions, and production fixes require separate owner approval.
// HOW IT WORKS
What does a technical SEO audit check?
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 checks, noindex detection, crawl depth analysis, JavaScript rendering checks, and a dated review of crawler controls. Provider documentation should be checked before access rules change.
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
Checks viewport setup, responsive behavior, usable controls, readable text, horizontal overflow, and mobile and desktop content and metadata parity. Google primarily uses its smartphone crawler; a separate mobile version is not required.
06
CORE WEB VITALS
Reports LCP, INP, and CLS field data only when CrUX has sufficient samples, evaluated at the 75th percentile. Otherwise it labels field data unavailable and separates Lighthouse lab diagnostics from HTML risk indicators.
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 support for IndexNow change notifications on participating search engines. A notification may speed discovery or crawling, but it never guarantees indexing.
// 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 reviews dated crawler controls, including OAI-SearchBot for ChatGPT Search and GPTBot for OpenAI model training. ChatGPT-User is user-triggered, is not used to decide Search inclusion, and robots.txt rules may not apply. Other providers use different tokens and purposes. Check each provider's current documentation before changing access.
The audit checks all 9 categories and produces a scored breakdown with prioritized issues. Every finding includes a specific fix recommendation.
Data and experimental-check boundaries
CrUX and PageSpeed Insights results depend on sufficient field samples, credentials, and provider quotas. Optional DataForSEO calls require the user's credentials, consume paid credits, and should run only after a cost estimate and confirmation. Experimental Lighthouse Agentic Browsing checks return fractional results, not 0-100 scores or ranking signals, and require a compatible Chrome version plus any applicable WebMCP origin-trial access. Treat them as review opportunities.
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 audit reviews dated crawler controls, including OAI-SearchBot for ChatGPT Search and GPTBot for OpenAI model training. ChatGPT-User is user-triggered, is not used to decide Search inclusion, and robots.txt rules may not apply. Check each provider's current documentation before changing access.
The audit reports LCP, INP, and CLS field data only when CrUX has sufficient samples, evaluated at the 75th percentile. Otherwise it labels field data unavailable and separates Lighthouse lab diagnostics and HTML risk indicators; lab data is not a Core Web Vitals field pass.
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.
