SEO Technical

Technical SEO Audit

Categories

1. Crawlability

• robots.txt: exists, valid, not blocking important resources
• XML sitemap: run "${CLAUDE_PLUGIN_ROOT}/scripts/claude-seo" run sitemap_discovery.py <url> --json; require a valid entry in found, and report stale or unsafe robots.txt declarations separately from working fallback locations
• 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
• Googlebot fetch limits: Googlebot fetches the first 2MB of HTML and first 64MB of a PDF (uncompressed; 15MB is the broader crawler-infra default). Long-standing, not a 2026 change, but inline base64 images, oversized inline CSS/JS, or bloated nav can push critical content/JSON-LD past the cap and out of the index. Keep key content + structured data within the first 2MB.
• Crawl rate auto-adjusts (backs off on 5xx/slow responses); there is no manual crawl-rate control (the legacy Search Console setting was removed Jan 2024). Influence crawling via sitemaps, server responsiveness, and robots controls.
• Google's canonical crawling/robots reference moved to developers.google.com/crawling (migrated 2025-11-20); IP-range files relocated to /crawling/ipranges/ and googlebot.json was renamed common-crawlers.json.
• AMP has no separate ranking advantage. Since 2026-07-01, Google Search sends users directly to publisher-hosted AMP URLs, so do not recommend AMP Cache, AMP Viewer, or signed exchange maintenance. Audit AMP against the same content, action-parity, and quality requirements as other pages.

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:

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 affect ChatGPT Search citability, which is governed by OAI-SearchBot, nor user-triggered browsing (ChatGPT-User). Check OAI-SearchBot for any citability claim; GPTBot status is evidence about training use only
• Blocking ClaudeBot prevents Anthropic model training but does NOT affect citability in Claude's own search features, which is governed by Claude-SearchBot (per Anthropic's crawler support article). Check Claude-SearchBot for any Claude-search citability claim; ClaudeBot status is evidence about training use only
• Blocking Applebot-Extended opts out of Apple Intelligence / generative-model training use but does NOT affect discoverability via Siri, Spotlight, or Safari, which follows Applebot (per Apple's support article); Applebot-Extended does not itself crawl
• ~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 the full AI crawler/fetcher taxonomy.

User-triggered fetchers ignore robots.txt by design. Google now documents Google-Agent (Project Mariner, agentic browsing) plus Google-NotebookLM and Google Messages as user-triggered fetchers that cannot be blocked via robots.txt. Use server-side access controls instead. By contrast, Google-Extended and Google-CloudVertexBot obey robots.txt. Emerging: Web Bot Auth (RFC 9421) lets bots authenticate cryptographically via a Signature-Agent header + key directory at agent.bot.goog (used by Google-Agent); reverse-DNS verification remains the fallback.

2. Indexability

• Canonical tags: self-referencing, no conflicts with noindex
• Duplicate content: near-duplicates, parameter URLs, www vs non-www
• Canonicalization fixes can take time: Google may retain corrected pages in a duplicate cluster for up to two weeks while re-evaluating them. Do not interpret an unchanged canonical immediately after a fix as proof that the fix failed.
• 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
• Back-button hijacking (spam-policy violation, malicious practices): flag pages that defeat the Back button via history.pushState/replaceState (including scripts injected by third-party ad/library platforms). Added to Google's spam policies 2026-04-13; enforcement live since 2026-06-15 (manual actions + automated demotions): treat as Critical.

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 & Page Experience

• 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: Googlebot Smartphone is the primary crawler (rollout completed 2024). A mobile version is not strictly required (Google says "very strongly recommended"), sites that don't work on mobile can still be indexed, but the real risk is content/parity loss, not hard exclusion.
• Mobile/desktop content parity (highest-value mobile check): equivalent primary content, matching robots meta tags, matching titles/descriptions, equivalent structured data, crawlable resources; avoid lazy-loading primary content that requires user interaction.
• Intrusive interstitials / ad density: flag full-page interstitials, standalone consent-redirect pages, persistent blocking dialogs, and excessive/distracting ad density (a named page-experience aspect). Acceptable: small banners, standard CMS/legal dialogs.
• "Read more" deep links: keep key content immediately visible on load (not behind tabs/accordions), don't hijack scroll on load, and preserve URL hash fragments, content hidden behind expandable sections is less likely to qualify.