Hreflang & International SEO

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

• Recommended when a selector/fallback URL exists: 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)
• An optional ISO 15924 script subtag is the documented, official mechanism for script: zh-Hant (Traditional) / zh-Hans (Simplified). Script may combine with a region, e.g. zh-Hans-US is valid (language + script + region).
• Common errors:
  • eng instead of en (ISO 639-2, not valid for hreflang)
  • jp instead of ja (incorrect code for Japanese)
  • zh is valid but ambiguous for script-specific pages; prefer zh-Hans or zh-Hant when targeting a script