En

en is the ISO 639-1 two-letter code for the English language. It is used to tag language content in software, websites, and data to indicate English. The three-letter ISO 639-2/639-3 code for English is eng, and the English Wikipedia uses en as its language code.

The tag en serves as a base tag in IETF language tags (RFC 5646) and is commonly extended with a region to form en-US, en-GB, en-CA, en-AU, etc., which reflect regional spelling, vocabulary, and conventions.

English is a West Germanic language that originated in England and has become one of the most widely spoken languages globally, with numerous regional varieties. The use of en as a language tag does not imply a single standard of English; locale-specific variants may apply.

In computing, language tags such as en are used in HTML, XML, JSON, and other data formats to control localization, content negotiation, and user interface language.

Other uses of en include typographic terms: en dash and en space refer to dash and space widths, named after the width of the letter "n." These typographic uses are distinct from the language code.

See also: ISO 639, IETF language tag, English language.