skilld
All skills
agricidaniel avatar

/seo-hreflang

@93b720e
by Agrici.Danielagricidaniel/claude-seo18k stars
2,665

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".

Ask your Agent

Use this Skill: https://skilld.dev/gh/agricidaniel/claude-seo/seo-hreflang

This session only. Nothing lands on disk.

referenceslocale-formats.md

≈881 tokens on demand. Your agent reads this file only when SKILL.md points to it.

Locale Format Reference for International SEO

Load this reference when validating content parity or generating localized content. Mismatched formats (e.g., US date format on a German page) signal poor localization and reduce user trust.

Original concept: Chris Muller (Pro Hub Challenge)

Number Formats

Locale Thousands Decimal Example
en-US , . 1,234.56
en-GB , . 1,234.56
de-DE . , 1.234,56
de-AT . , 1.234,56
de-CH ' . 1'234.56
fr-FR (space) , 1 234,56
fr-CA (space) , 1 234,56
es-ES . , 1.234,56
es-MX , . 1,234.56
ja-JP , . 1,234
pt-BR . , 1.234,56
it-IT . , 1.234,56
nl-NL . , 1.234,56
ko-KR , . 1,234
zh-CN , . 1,234.56

Date Formats

Locale Format Example
en-US MM/DD/YYYY 04/14/2026
en-GB DD/MM/YYYY 14/04/2026
de-DE DD.MM.YYYY 14.04.2026
fr-FR DD/MM/YYYY 14/04/2026
es-ES DD/MM/YYYY 14/04/2026
ja-JP YYYY/MM/DD or YYYY年MM月DD日 2026/04/14
pt-BR DD/MM/YYYY 14/04/2026
ko-KR YYYY.MM.DD 2026.04.14
zh-CN YYYY年MM月DD日 2026年04月14日

Currency Formats

Locale Symbol Placement Example
en-US $ Before $1,234.56
en-GB £ Before £1,234.56
de-DE € After (space) 1.234,56 €
fr-FR € After (space) 1 234,56 €
es-ES € After (space) 1.234,56 €
ja-JP ¥ Before ¥1,234
pt-BR R$ Before R$ 1.234,56
ko-KR ₩ Before ₩1,234
zh-CN ¥ Before ¥1,234.56
de-CH CHF Before CHF 1'234.56

Address Formats

Region Order Example
US/CA Street, City, State ZIP 123 Main St, Austin, TX 78701
UK Street, City, Postcode 10 Downing St, London, SW1A 2AA
DE/AT Street Nr, PLZ City Hauptstr. 1, 10115 Berlin
FR Street, Code Postal City 1 Rue de Rivoli, 75001 Paris
JP Postal City District Street 〒100-0001 東京都千代田区千代田1-1

Phone Formats

Region Format Example
US +1 (XXX) XXX-XXXX +1 (512) 555-0123
UK +44 XXXX XXXXXX +44 2071 234567
DE +49 XXX XXXXXXX +49 30 12345678
FR +33 X XX XX XX XX +33 1 23 45 67 89
JP +81 X-XXXX-XXXX +81 3-1234-5678

Text Expansion Ratios (vs English)

Language Expansion Impact
German +25-35% Longer headlines, buttons, navigation labels
French +15-25% Moderate expansion
Spanish +15-25% Moderate expansion
Italian +15-25% Moderate expansion
Portuguese +15-25% Moderate expansion
Dutch +10-20% Slight expansion
Japanese -10-25% Contraction (more compact)
Korean -10-20% Contraction
Chinese -20-30% Significant contraction

Validation Rules

When checking locale format consistency:

  1. Scan for number patterns on the page (prices, statistics, measurements)
  2. Compare against the expected format for the page's declared language
  3. Flag US-format numbers on non-US pages (e.g., "$1,234.56" on a de-DE page)
  4. Check date formats in blog posts, copyright notices, update timestamps
  5. Verify currency symbols match the target market
  6. Check that phone numbers use international format with correct country code

Source: SKILL.md on GitHub

Third-party checks

1 warning1d5 checks · Risk SAFE
  • Gen Agent Trust Hub1d

    The skill is an SEO utility for internationalization (hreflang) audits. It is generally safe but possesses a surface for indirect prompt injection because it analyzes external websites and local directories. It also suggests the use of a vendor-provided script for content quality assessments.

  • Socket1d

    No alerts

  • Snyk1d

    Risk: MEDIUM · 1 issue

  • Runlayer7mo

    1 file scanned · No issues

  • ZeroLeaks5mo

    Score: 93/100 · 2 sections analyzed

Provenance

Signed by skilld at 93b720e. This ties the file your Agent reads to that commit on GitHub. It does not review the instructions.

Last checked against GitHub 2 days ago.

Activeupdated 3 days ago

Capability

user-invocable
true
argument-hint
[url]
metadata
{
  "author": "AgriciDaniel",
  "version": "2.4.1",
  "category": "seo"
}

Topics

  • SEO
  • hreflang
  • international-seo
  • i18n
  • multi-language
  • validation
  • xml-sitemap
  • language-codes

README badge

README badge for agricidaniel/claude-seo/seo-hreflang

What it does

Audits and generates correct hreflang implementations for multi-language and multi-region sites, validating language/region codes, self-references, bidirectional tags, and x-default fallbacks. Detects critical mistakes like missing return tags, invalid ISO codes (e.g. `eng` instead of `en`, `en-uk` instead of `en-GB`), and protocol mismatches that cause Google to ignore hreflang signals.

Generated from the current SKILL.md.

Frequently asked

Does this skill work with HTTP headers and XML sitemaps, or just HTML tags?
It supports all three: HTML link tags, HTTP headers (for non-HTML files like PDFs), and XML sitemaps. Sitemap implementation is recommended for large sites with 50+ language variants.
What language and region codes does this skill validate?
It validates ISO 639-1 two-letter language codes (en, fr, de, ja) and ISO 3166-1 Alpha-2 region codes (US, GB, BR). It detects common errors like 'eng' instead of 'en', 'jp' instead of 'ja', and invalid region codes like 'en-uk'.
Does this skill check for bidirectional hreflang relationships?
Yes. It validates that hreflang relationships are bidirectional — if page A links to page B, page B must link back to page A. Missing return tags invalidate the hreflang signal for both pages.
Can this skill work with cross-domain hreflang setups?
Yes. It supports cross-domain hreflang (e.g., example.com and example.de) but requires return tags on both domains and recommends sitemap-based implementation for cross-domain configurations.
Does this skill assess content quality across language versions?
Yes. It includes a content parity audit that checks page existence, section structure, SEO elements, word count ratios, freshness, and cultural markers across all language versions. It also evaluates cultural adaptation for each locale against built-in profiles.

Generated from the current SKILL.md. These answers refresh after source changes.