BCP 47 Language Tags API
IETF BCP 47 language tags (locales) as an API, built on the IANA Language Subtag Registry — 9,200+ subtags (languages, scripts, regions, variants, extlangs and grandfathered tags). The headline /parse endpoint validates and decomposes any language tag (e.g. zh-Hant-TW → Chinese + Han Traditional script + Taiwan; en-Latn-US, de-CH-1996, i-klingon) into its labelled subtags, flags invalid or deprecated parts, and recognises pre-registered redundant/grandfathered tags. Look up an individual subtag (de → German, Hant → Han Traditional, 419 → Latin America), or search the registry by description. Ideal for internationalization (i18n), locale validation, content negotiation and language-aware apps.
api.oanor.com/bcp47-api