International SEO & AI Search Optimization (GEO)
Part 1: Hreflang & International SEO
When NOT to Use Hreflang
- Single-language, single-country site
- Machine-translated pages without real localization
- Content behind login or geo-blocking (must return 200 to Googlebot)
- No search presence in target markets
- Pagination/filter pages (only canonical pages)
Validation Checks
- Self-referencing: Every page MUST include hreflang pointing to itself. URL must exactly match canonical.
- Return tags: If A points to B, B MUST point back to A. Full bidirectional mesh.
- x-default: Required on every page with hreflang. Points to language selector or most universal version.
- Language codes (ISO 639-1):
| Correct |
Wrong |
Note |
ja |
jp |
jp = country, ja = language |
zh-Hans |
zh-cn |
Must use script subtag |
ko |
kr |
kr = country |
en-GB |
en-uk |
UK not valid ISO 3166-1 |
- Region codes: ISO 3166-1 Alpha-2, uppercase (
en-GB, not en-gb).
- Canonical alignment: Hreflang only on canonical URLs. Non-canonical = ignored.
- Protocol/URL consistency: All HTTPS, consistent www/trailing slash.
5 Most Common Errors
| Error |
Fix |
| Missing return tags |
Add matching B>A tags |
| Missing self-reference |
Add self-referencing tag |
Wrong codes (jp, kr) |
Use ISO 639-1 |
| Hreflang on non-canonical |
Move to canonical URL only |
| x-default missing/wrong |
Add to every page in set |
Implementation Methods
See references/hreflang-examples.md for code examples (HTML link tags, HTTP headers, XML sitemap) and generation process.
- HTML link tags: Best for <50 variants
- HTTP headers: Best for non-HTML (PDFs)
- XML sitemap: Best for large sites, cross-domain
Output: HREFLANG-AUDIT.md
Summary (pages, variants, issues, method), validation results per page, critical issues with fixes, generated code, GSC verification steps.
Part 2: AI Search / GEO Optimization (March 2026)
See references/geo-optimization.md for stats, brand signal correlations, AI crawler config, llms.txt, RSL 1.0, and platform-specific optimization.
GEO Analysis Criteria
| Dimension |
Weight |
Key Signals |
| Passage-level citability |
25% |
134-167 word answer blocks, direct answer first, specific facts, attribution |
| Structural readability |
20% |
Question headings, short paragraphs, tables, lists, FAQ |
| Multi-modal content |
15% |
Text + images/video/infographics/tools (156% higher citation rates) |
| Authority & brand signals |
20% |
Author byline, pub dates, source citations, Wikipedia/Reddit/YouTube presence |
| Technical accessibility |
20% |
SSR required (AI crawlers don't execute JS), robots.txt access, llms.txt |
Critical: Brand mentions correlate 3x more strongly with AI visibility than backlinks.
Output: GEO-ANALYSIS.md
- GEO Readiness Score: XX/100 (breakdown by dimension)
- Platform Scores table
- AI Crawler Access Status
- llms.txt Status
- Brand Mention Analysis
- Passage-Level Citability (3 best, 3 worst with rewrites)
- SSR Check
- RSL 1.0 Status
- Top 5 Highest-Impact Actions
- Content Reformatting Suggestions (before/after)
1---2name: seo-international3description: SEO internacional y local: hreflang, sitios multi-idioma/región, GEO (visibilidad en AI Overviews, ChatGPT, Perplexity, Claude). Cubre x-default, ccTLD, llms.txt, RSL 1.0. Usar cuando: "hreflang", "SEO internacional", "multi-idioma", "multi-región", "geo-targeting", "llms.txt", "AI search", "GEO", "aparecer en ChatGPT/Perplexity", "citas en IA", "país incorrecto en resultados", "x-default". "AI visibility", "generative engine optimization", "AI Mode", "cited by AI", "zero-click AI results", "AI search traffic", "local SEO", "Google Business Profile".4---56# International SEO & AI Search Optimization (GEO)78---910## Part 1: Hreflang & International SEO1112### When NOT to Use Hreflang131. Single-language, single-country site142. Machine-translated pages without real localization153. Content behind login or geo-blocking (must return 200 to Googlebot)164. No search presence in target markets175. Pagination/filter pages (only canonical pages)1819### Validation Checks20211. **Self-referencing:** Every page MUST include hreflang pointing to itself. URL must exactly match canonical.222. **Return tags:** If A points to B, B MUST point back to A. Full bidirectional mesh.233. **x-default:** Required on every page with hreflang. Points to language selector or most universal version.244. **Language codes (ISO 639-1):**2526| Correct | Wrong | Note |27|---------|-------|------|28| `ja` | `jp` | jp = country, ja = language |29| `zh-Hans` | `zh-cn` | Must use script subtag |30| `ko` | `kr` | kr = country |31| `en-GB` | `en-uk` | UK not valid ISO 3166-1 |32335. **Region codes:** ISO 3166-1 Alpha-2, uppercase (`en-GB`, not `en-gb`).346. **Canonical alignment:** Hreflang only on canonical URLs. Non-canonical = ignored.357. **Protocol/URL consistency:** All HTTPS, consistent www/trailing slash.3637### 5 Most Common Errors3839| Error | Fix |40|-------|-----|41| Missing return tags | Add matching B>A tags |42| Missing self-reference | Add self-referencing tag |43| Wrong codes (`jp`, `kr`) | Use ISO 639-1 |44| Hreflang on non-canonical | Move to canonical URL only |45| x-default missing/wrong | Add to every page in set |4647### Implementation Methods48See `references/hreflang-examples.md` for code examples (HTML link tags, HTTP headers, XML sitemap) and generation process.4950- **HTML link tags:** Best for <50 variants51- **HTTP headers:** Best for non-HTML (PDFs)52- **XML sitemap:** Best for large sites, cross-domain5354### Output: HREFLANG-AUDIT.md55Summary (pages, variants, issues, method), validation results per page, critical issues with fixes, generated code, GSC verification steps.5657---5859## Part 2: AI Search / GEO Optimization (March 2026)6061See `references/geo-optimization.md` for stats, brand signal correlations, AI crawler config, llms.txt, RSL 1.0, and platform-specific optimization.6263### GEO Analysis Criteria6465| Dimension | Weight | Key Signals |66|-----------|--------|-------------|67| Passage-level citability | 25% | 134-167 word answer blocks, direct answer first, specific facts, attribution |68| Structural readability | 20% | Question headings, short paragraphs, tables, lists, FAQ |69| Multi-modal content | 15% | Text + images/video/infographics/tools (156% higher citation rates) |70| Authority & brand signals | 20% | Author byline, pub dates, source citations, Wikipedia/Reddit/YouTube presence |71| Technical accessibility | 20% | SSR required (AI crawlers don't execute JS), robots.txt access, llms.txt |7273**Critical:** Brand mentions correlate 3x more strongly with AI visibility than backlinks.7475### Output: GEO-ANALYSIS.md761. GEO Readiness Score: XX/100 (breakdown by dimension)772. Platform Scores table783. AI Crawler Access Status794. llms.txt Status805. Brand Mention Analysis816. Passage-Level Citability (3 best, 3 worst with rewrites)827. SSR Check838. RSL 1.0 Status849. Top 5 Highest-Impact Actions8510. Content Reformatting Suggestions (before/after)
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