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Language Code Lookup

The definitive ISO 639-1 & 639-2 reference for developers. Features fuzzy search, country mapping, BCP 47 formatting, and bulk export to JSON/YAML/Android/iOS.

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Category Code Utilities
📚 Database: 0 Languages
🌍 ISO 639-1 • 639-2 • IETF
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Found: 0
Language Native 639-1 639-2 Script Action
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About

Localization is often treated as an afterthought, yet incorrect language tagging is a primary cause of silent failures in global software distribution. Whether configuring Accept-Language headers, defining HTML lang attributes, or setting up translation management systems (TMS), precision is non-negotiable.

This tool is an architect-grade reference engine for ISO 639-1 (2-letter) and ISO 639-2 (3-letter) standards. Unlike static wiki tables, it features a Levenshtein-based fuzzy search capable of resolving typos (e.g., "Japaneese") and a reverse-lookup engine that maps countries to their dominant languages (e.g., "Brazil" → pt-BR). The integrated Bulk Processor transforms messy lists of language names into strictly formatted JSON, YAML, or XML configuration files for React Intl, Android, iOS, and Python environments.

iso-639-1 language-codes i18n localization bcp-47 country-codes developer-tools

Formulas

Professional internalization relies on the IETF BCP 47 standard for constructing language tags. The structure is hierarchical, moving from general to specific.

Tag = LowerCase(Language) + [-TitleCase(Script)] + [-UpperCase(Region)]

Example for Serbian (Language) written in Cyrillic (Script) as used in Serbia (Region):

sr + Cyrl + RS = sr-Cyrl-RS

Reference Data

NameNative639-1639-2ScriptExamples
EnglishEnglishenengLatnen-US, en-GB
Chinese (Simplified)中文 (简体)zhzhoHanszh-CN, zh-SG
SpanishEspañolesspaLatnes-ES, es-MX
ArabicالعربيةararaArabar-SA, ar-EG
Hindiहिन्दीhihinDevahi-IN
FrenchFrançaisfrfraLatnfr-FR, fr-CA
RussianРусскийrurusCyrlru-RU
PortuguesePortuguêsptporLatnpt-PT, pt-BR
Japanese日本語jajpnJpanja-JP
GermanDeutschdedeuLatnde-DE, de-AT

Frequently Asked Questions

ISO 639-1 uses 2-letter codes (e.g., "en", 'ja') and covers major world languages. It is the preferred standard for modern web development and HTML "lang" attributes. ISO 639-2 uses 3-letter codes (e.g., "eng", 'jpn') and covers a much wider range of languages, including historical and indigenous ones. If a 639-1 code exists, you should generally use it.
The processor uses a waterfall logic: 1. Exact Code Match, 2. Exact Name Match, 3. Fuzzy Name Match, 4. Country Association. If you input "Brazil", the engine infers "pt-BR". If you input "Chinese", it defaults to "zh-CN" (Simplified). Unresolved entries are flagged as "null" or preserved as comments depending on settings.
The standard includes "Bibliographic" (B) codes derived from English names (e.g., "ger" for German) and "Terminological" (T) codes derived from native names (e.g., "deu" for Deutsch). For software development, the "T" codes are the standard. This tool defaults to "T" codes.
Yes. The database includes the default script for each language. In the "Locale" output format, script codes are automatically omitted if they are the default for that language (e.g., "en-US" not 'en-Latn-US'), but included where necessary for disambiguation (e.g., 'zh-Hant-TW').