BCP 47 Validator

This service lets you validate language tags such as de-CH or en-US according to BCP 47 (formerly RFC 4646) and the IANA Language Subtag Registry. The Language Tag Extensions Registry is not used by this service, but this may change in the future.

Separate multiple tags by comma or whitespace. Do not include quality values such as ;q=0.8. As you type, the background color denotes whether all tags are well-formed and valid, any tag is invalid or any tag is not well-formed.

Language tags:
Output format:
Input
en-US-boont
Canonical
en-US-boont
Input is canonical
True
Well-formed
True
Valid
True
Registry date
2024-05-16
Primary language subtag
en – English
Extended language subtags
Script subtag
Region subtag
US – United States
Variant subtags
boont – Boontling
Extension subtags
Private subtags
Messages

Feedback

Don't hesitate to send suggestions and comments to Christoph Schneegans (christoph@schneegans.de).