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Hreflang checker
Put in a URL. The tool reads the hreflang tags and checks the things that usually break them: invalid language codes, missing x-default, relative URLs and duplicates.
Fetched live, exactly as a crawler receives it.
The rules
- Codes are ISO 639-1 language plus optional ISO 3166-1 region:
en,en-gb,de-at. Region alone (gb) is invalid;en-ukis the classic wrong guess foren-gb. - Every URL must be absolute.
- Annotations must be reciprocal: if A lists B, B must list A, or both are ignored.
- Each page should list itself (self-referencing hreflang).
x-defaultnames the fallback for unmatched users; usually your language selector or global page.
Hreflang tells Google which version to show which users. It does not improve rankings. When it is missing you usually see the wrong country version ranking instead of the right one.