seo-hreflang

name	seo-hreflang
description	Hreflang and international SEO audit, validation, and generation. Detects common mistakes, validates language/region codes, and generates correct hreflang implementations. Use when user says "hreflang", "i18n SEO", "international SEO", "multi-language", "multi-region", or "language tags".
risk	unknown
source	https://github.com/AgriciDaniel/claude-seo
date_added	2026-03-21
user-invokable	true
argument-hint	[url]
allowed-tools	["Read","Grep","Glob","Bash","WebFetch"]

Hreflang & International SEO

When to Use

• Use when validating or generating hreflang for multilingual or multiregional sites.
• Use when the user mentions international SEO, language tags, x-default, or hreflang issues.
• Use when auditing locale alternates across HTML, headers, or sitemap implementations.

Validate existing hreflang implementations or generate correct hreflang tags for multi-language and multi-region sites. Supports HTML, HTTP header, and XML sitemap implementations.

Validation Checks

1. Self-Referencing Tags

• Every page must include an hreflang tag pointing to itself
• The self-referencing URL must exactly match the page's canonical URL
• Missing self-referencing tags cause Google to ignore the entire hreflang set

2. Return Tags

• If page A links to page B with hreflang, page B must link back to page A
• Every hreflang relationship must be bidirectional (A→B and B→A)
• Missing return tags invalidate the hreflang signal for both pages
• Check all language versions reference each other (full mesh)

3. x-default Tag

• Required: designates the fallback page for unmatched languages/regions
• Typically points to the language selector page or English version
• Only one x-default per set of alternates
• Must also have return tags from all other language versions

4. Language Code Validation

• Must use ISO 639-1 two-letter codes (e.g., en, fr, de, ja)
• Common errors:
  • eng instead of en (ISO 639-2, not valid for hreflang)
  • jp instead of ja (incorrect code for Japanese)
  • zh without region qualifier (ambiguous; use zh-Hans or zh-Hant)

5. Region Code Validation

• Optional region qualifier uses ISO 3166-1 Alpha-2 (e.g., en-US, en-GB, pt-BR)
• Format: language-REGION (lowercase language, uppercase region)
• Common errors:
  • en-uk instead of en-GB (UK is not a valid ISO 3166-1 code)
  • es-LA (Latin America is not a country; use specific countries)