geo-technical（地质技术）

GEO Technical SEO Audit

Purpose

Technical SEO forms the foundation of both traditional search visibility and AI search citation. A technically broken site cannot be crawled, indexed, or cited by any platform. This skill audits 8 categories of technical health with specific attention to GEO requirements — most critically, server-side rendering (AI crawlers do not execute JavaScript) and AI crawler access (many sites inadvertently block AI crawlers in robots.txt).

How to Use This Skill

1. Collect the target URL (homepage + 2-3 key inner pages)
2. Fetch each page using curl/WebFetch to get raw HTML and HTTP headers
3. Run through each of the 8 audit categories below
4. Score each category using the rubric
5. Generate GEO-TECHNICAL-AUDIT.md with results

Category 1: Crawlability (15 points)

1.1 robots.txt Validity

• Fetch https://[domain]/robots.txt
• Check for syntactic validity: proper User-agent, Allow, Disallow directives
• Check for common errors: missing User-agent, wildcards blocking important paths, Disallow: / blocking entire site
• Verify XML sitemap is referenced: Sitemap: https://[domain]/sitemap.xml

1.2 AI Crawler Access (CRITICAL for GEO)

Check robots.txt for directives targeting these AI crawlers:

Scoring for AI crawler access:

• All major AI crawlers allowed: 5 points
• Some blocked but Googlebot + Bingbot allowed: 3 points
• GPTBot or PerplexityBot blocked: 1 point (significant GEO impact)
• Googlebot blocked: 0 points (fatal)

Important nuance: Blocking Google-Extended does NOT block Googlebot. Google-Extended only controls AI training data usage, not search indexing. However, blocking Google-Extended may reduce presence in AI Overviews. Recommend allowing Google-Extended unless there is a specific data licensing concern.

1.3 XML Sitemaps

• Fetch sitemap (check robots.txt for location, or try /sitemap.xml, /sitemap_index.xml)
• Validate XML syntax
• Check for <lastmod> dates (should be present and accurate)
• Count URLs — compare to expected number of indexable pages
• Check for sitemap index if large site (50,000+ URLs per sitemap max)
• Verify all sitemap URLs return 200 status codes (sample check)

1.4 Crawl Depth

• Homepage = depth 0. Check that all important pages are reachable within 3 clicks (depth 3)
• Pages at depth 4+ receive significantly less crawl budget and are less likely to be cited by AI
• Check internal linking: are key content pages linked from the homepage or main navigation?

1.5 Noindex Management

• Check for <meta name="robots" content="noindex"> on pages that SHOULD be indexed
• Check for X-Robots-Tag: noindex HTTP headers
• Common mistakes: noindex on paginated pages, category pages, or key landing pages

Category Scoring:

Category 2: Indexability (12 points)

2.1 Canonical Tags

• Every indexable page must have a <link rel="canonical" href="..."> tag
• Canonical must point to itself (self-referencing) for the authoritative version
• Check for conflicting canonicals (canonical in HTML vs. HTTP header)
• Check for canonical chains (A canonicals to B, B canonicals to C — should be A to C)

2.2 Duplicate Content

• Check for www vs. non-www (both should resolve, one should redirect)
• Check for HTTP vs. HTTPS (HTTP should redirect to HTTPS)
• Check for trailing slash consistency (pick one pattern and redirect the other)
• Check for parameter-based duplicates (?sort=price creating duplicate pages)

2.3 Pagination

• If paginated content exists, check for rel="next" / rel="prev" (note: Google ignores these as of 2019, but Bing still uses them)
• Preferred: use rel="canonical" on paginated pages pointing to a view-all page or the first page
• Ensure paginated pages are not noindexed if they contain unique content

2.4 Hreflang (international sites)

• Check for <link rel="alternate" hreflang="xx"> tags
• Validate: reciprocal hreflang (if page A points to page B, B must point back to A)
• Validate: x-default fallback exists
• Check for language/region code validity (ISO 639-1 / ISO 3166-1)

2.5 Index Bloat

• Estimate number of indexed pages (check sitemap count, use site:domain.com estimate)
• Compare indexed pages to actual valuable content pages
• Flag if indexed pages significantly exceed content pages (index bloat from thin/duplicate/parameter pages)

Category Scoring:

Category 3: Security (10 points)

3.1 HTTPS Enforcement

• Site must load over HTTPS
• HTTP must redirect to HTTPS (301 redirect)
• No mixed content warnings (HTTP resources on HTTPS pages)
• SSL/TLS certificate must be valid and not expired

3.2 Security Headers

Check HTTP response headers for:

Category Scoring:

Category 4: URL Structure (8 points)

4.1 Clean URLs

• URLs should be human-readable: /blog/seo-guide not /blog?id=12345
• No session IDs in URLs
• Lowercase only (no mixed case)
• Hyphens for word separation (not underscores)
• No special characters or encoded spaces

4.2 Logical Hierarchy

• URL path should reflect site architecture: /category/subcategory/page
• Flat where appropriate — avoid unnecessarily deep nesting
• Consistent pattern across the site

4.3 Redirect Chains

• Check for redirect chains (A redirects to B redirects to C)
• Maximum 1 hop recommended (A redirects to C directly)
• Check for redirect loops
• All redirects should be 301 (permanent), not 302 (temporary), unless intentionally temporary

4.4 Parameter Handling

• URL parameters should not create duplicate indexable pages
• Use canonical tags or robots.txt Disallow for parameter variations
• Configure parameter handling in Google Search Console and Bing Webmaster Tools

Category Scoring:

Category 5: Mobile Optimization (10 points)

Critical Context

As of July 2024, Google crawls ALL sites exclusively with mobile Googlebot. There is no desktop crawling. If your site does not work on mobile, it does not work for Google. Period.

5.1 Responsive Design

• Check for <meta name="viewport" content="width=device-width, initial-scale=1">
• Content must not require horizontal scrolling on mobile
• No fixed-width layouts wider than viewport

5.2 Tap Targets

• Interactive elements (buttons, links) must be at least 48x48 CSS pixels
• Minimum 8px spacing between tap targets
• Check that navigation is usable on mobile

5.3 Font Sizes

• Base font size should be at least 16px
• No text requiring zoom to read
• Sufficient contrast ratio (WCAG AA: 4.5:1 for normal text, 3:1 for large text)

5.4 Mobile Content Parity

• All content visible on desktop must also be visible on mobile
• No hidden content behind "read more" toggles that Googlebot cannot expand (though Google has improved at expanding these as of 2025)
• Images and media must load on mobile

Category Scoring:

Category 6: Core Web Vitals (15 points)

2026 Metrics and Thresholds

Core Web Vitals use the 75th percentile of real user data (field data) as the benchmark. Lab data is useful for debugging but field data determines the ranking signal.

How to Assess Without CrUX Data

When real user data is unavailable, estimate from page characteristics:

• LCP: Check largest above-fold element. Is it an image (check size/format)? Is it text (check web font loading)? Server response time (TTFB)?
• INP: Check for heavy JavaScript on page. Long tasks (>50ms) block interactivity. Check for third-party scripts.
• CLS: Check for images without explicit width/height. Check for dynamically inserted content above the fold. Check for web fonts causing layout shift (FOUT/FOIT).

Common LCP Fixes

1. Optimize hero images: WebP/AVIF format, correct sizing, preload with <link rel="preload">
2. Reduce server response time (TTFB < 800ms)
3. Eliminate render-blocking CSS/JS
4. Preconnect to critical third-party origins

Common INP Fixes

1. Break up long tasks (>50ms) into smaller chunks using requestIdleCallback or scheduler.yield()
2. Reduce third-party JavaScript
3. Use content-visibility: auto for off-screen content
4. Debounce/throttle event handlers

Common CLS Fixes

1. Always include width and height attributes on images and videos
2. Reserve space for ads and embeds with CSS aspect-ratio or explicit dimensions
3. Use font-display: swap with size-adjusted fallback fonts
4. Avoid inserting content above existing content after page load

Category Scoring:

Category 7: Server-Side Rendering (15 points) — CRITICAL FOR GEO

Why SSR Is Mandatory for AI Visibility

AI crawlers (GPTBot, PerplexityBot, ClaudeBot, etc.) do NOT execute JavaScript. They fetch the raw HTML and parse it. If your content is rendered client-side by React, Vue, Angular, or any other JavaScript framework, AI crawlers see an empty page.

Even Googlebot, which does execute JavaScript, deprioritizes JS-rendered content due to the additional crawl budget required. Google processes JS rendering in a separate "rendering queue" that can delay indexing by days or weeks.

Detection Method

1. Fetch the page with curl (no JavaScript execution): curl -s [URL]
2. Compare the raw HTML to the rendered DOM (via browser)
3. If key content (headings, paragraphs, product info, article text) is MISSING from the curl output, the site relies on client-side rendering

What to Check

• Main content text: Is the article body / product description / page content in the raw HTML?
• Headings: Are H1, H2, H3 tags present in raw HTML?
• Navigation: Is the main navigation server-rendered?
• Structured data: Is JSON-LD in the raw HTML or injected by JavaScript?
• Meta tags: Are title, description, canonical, OG tags in the raw HTML?
• Internal links: Are navigation and content links in the raw HTML? (Critical for crawlability)

SSR Solutions to Recommend

Scoring Detail

• All key content server-rendered: 15 points
• Main content server-rendered but some elements JS-only: 10 points
• Critical content requires JS (product info, article text): 5 points
• Entire page is client-rendered (empty body in raw HTML): 0 points

Category Scoring:

Category 8: Page Speed & Server Performance (15 points)

8.1 Time to First Byte (TTFB)

• Target: < 800ms (ideally < 200ms)
• Measure with curl: curl -o /dev/null -s -w 'TTFB: %{time_starttransfer}s\n' [URL]
• If TTFB > 800ms: check server location, caching, database queries, CDN usage

8.2 Resource Optimization

• Total page weight target: < 2MB (critical pages < 1MB)
• Check for uncompressed resources (gzip/brotli compression should be enabled)
• Check for unminified CSS and JavaScript
• Check for unused CSS/JS (can represent 50%+ of downloaded bytes on many sites)

8.3 Image Optimization

• Check image formats: WebP or AVIF preferred over JPEG/PNG
• Check for oversized images (images larger than display size)
• Check for lazy loading: images below fold should have loading="lazy"
• Check for explicit dimensions (width/height attributes prevent CLS)
• Above-fold images should NOT be lazy loaded (harms LCP)

8.4 Code Splitting and Lazy Loading

• JavaScript should be code-split so each page only loads what it needs
• Check for large JavaScript bundles (> 200KB compressed is a warning, > 500KB is critical)
• Third-party scripts should load asynchronously (async or defer)
• Check for render-blocking resources in <head>

8.5 Caching

• Check Cache-Control headers on static resources (images, CSS, JS)
• Static assets should have long cache times: max-age=31536000 (1 year) with content-hashed filenames
• HTML pages should have shorter cache or no-cache with validation (ETag or Last-Modified)

8.6 CDN Usage

• Check if static resources are served from a CDN (different domain or CDN-specific headers)
• For global audience, CDN is critical for consistent performance
• Check for CDN-specific headers: CF-Ray (Cloudflare), X-Cache (AWS CloudFront), X-Served-By (Fastly)

Category Scoring:

IndexNow Protocol

What It Is

IndexNow is an open protocol that allows websites to notify search engines instantly when content is created, updated, or deleted. Supported by Bing, Yandex, Seznam, and Naver. Google does NOT support IndexNow but monitors the protocol.

Why It Matters for GEO

ChatGPT uses Bing's index. Bing Copilot uses Bing's index. Faster Bing indexing means faster AI visibility on two major platforms.

Implementation Check

1. Check for IndexNow key file: https://[domain]/.well-known/indexnow-key.txt or similar
2. Check if CMS has IndexNow plugin (WordPress: IndexNow plugin; many modern CMS platforms support it natively)
3. If not implemented, recommend adding it with instructions

Overall Scoring

Score Interpretation

• 90-100: Excellent — technically sound for both traditional SEO and GEO
• 70-89: Good — minor issues to address but fundamentally solid
• 50-69: Needs Work — significant technical debt impacting visibility
• 30-49: Poor — major issues blocking crawling, indexing, or AI visibility
• 0-29: Critical — fundamental technical failures requiring immediate attention

Output Format

Generate GEO-TECHNICAL-AUDIT.md with:

# GEO Technical SEO Audit — [Domain]
Date: [Date]

## Technical Score: XX/100

## Score Breakdown
| Category | Score | Status |
|---|---|---|
| Crawlability | XX/15 | Pass/Warn/Fail |
| Indexability | XX/12 | Pass/Warn/Fail |
| Security | XX/10 | Pass/Warn/Fail |
| URL Structure | XX/8 | Pass/Warn/Fail |
| Mobile Optimization | XX/10 | Pass/Warn/Fail |
| Core Web Vitals | XX/15 | Pass/Warn/Fail |
| Server-Side Rendering | XX/15 | Pass/Warn/Fail |
| Page Speed & Server | XX/15 | Pass/Warn/Fail |

Status: Pass = 80%+ of category points, Warn = 50-79%, Fail = <50%

## AI Crawler Access
| Crawler | User-Agent | Status | Recommendation |
|---|---|---|---|
| GPTBot | GPTBot | Allowed/Blocked | [Action] |
| Googlebot | Googlebot | Allowed/Blocked | [Action] |
[Continue for all AI crawlers]

## Critical Issues (fix immediately)
[List with specific page URLs and what is wrong]

## Warnings (fix this month)
[List with details]

## Recommendations (optimize this quarter)
[List with details]

## Detailed Findings
[Per-category breakdown with evidence]