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)
  • Region without language prefix

6. Canonical URL Alignment

• Hreflang tags must only appear on canonical URLs
• If a page has rel=canonical pointing elsewhere, hreflang on that page is ignored
• The canonical URL and hreflang URL must match exactly (including trailing slashes)
• Non-canonical pages should not be in any hreflang set

7. Protocol Consistency

• All URLs in an hreflang set must use the same protocol (HTTPS or HTTP)
• Mixed HTTP/HTTPS in hreflang sets causes validation failures
• After HTTPS migration, update all hreflang tags to HTTPS

8. Cross-Domain Support

• Hreflang works across different domains (e.g., example.com and example.de)
• Cross-domain hreflang requires return tags on both domains
• Verify both domains are verified in Google Search Console
• Sitemap-based implementation recommended for cross-domain setups

Common Mistakes

Implementation Methods

Method 1: HTML Link Tags

Best for: Sites with <50 language/region variants per page.

<link rel="alternate" hreflang="en-US" href="https://example.com/page" />
<link rel="alternate" hreflang="en-GB" href="https://example.co.uk/page" />
<link rel="alternate" hreflang="fr" href="https://example.com/fr/page" />
<link rel="alternate" hreflang="x-default" href="https://example.com/page" />

Place in <head> section. Every page must include all alternates including itself.

Method 2: HTTP Headers

Best for: Non-HTML files (PDFs, documents).

Link: <https://example.com/page>; rel="alternate"; hreflang="en-US",
      <https://example.com/fr/page>; rel="alternate"; hreflang="fr",

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