What is validated
- Codes: ISO 639-1 language (en), optionally with a script (zh-Hant) and an ISO 3166-1 region (en-GB) or UN M.49 region (es-419), or x-default.
- Every alternate is an absolute URL.
- No language/region code appears twice.
- An x-default exists when there are several alternates, and the page lists itself.
Reciprocal links
Hreflang only works when every version links back to the others. That needs fetching each alternate; this tool checks the one page you give it. Run it on each language version to compare.
Frequently asked questions
Is "en-UK" valid?
No. The ISO region code for the United Kingdom is GB, so use en-GB.
Do I need hreflang for a single-language site?
No. The checker will simply report that there are no hreflang links.