A complete reference of ISO 639 language codes covering both two-letter (639-1) and three-letter (639-2/639-3) standards, along with English names, native names, and language family classifications. The go-to dataset for internationalization, localization, and multilingual content systems.
Pro tip: Use the ISO 639-1 two-letter codes for HTML lang attributes and HTTP Accept-Language headers — they are the most widely supported format across web standards.
Select which columns to include in your download.
About the ISO 639 Language Codes Dataset
This dataset provides a comprehensive list of language codes defined by the ISO 639 family of standards. Each entry includes the ISO 639-1 two-letter code (where assigned), the ISO 639-2 three-letter bibliographic code, the English name of the language, its native or endonym name, and the language family it belongs to. The list covers all languages with assigned ISO 639-1 codes as well as additional languages that only have three-letter codes, providing broad coverage for both widely spoken and less common languages used in software localization and content classification.
Common Use Cases
Language codes are foundational to internationalization and localization workflows:
- Website localization: Set the correct
langattribute on HTML elements, configurehreflangtags for multilingual SEO, and populate language selector dropdowns with standardized code-to-name mappings. - Content management: Tag articles, documents, and media files with their language code to enable filtered search, automatic translation routing, and locale-specific content delivery.
- API development: Validate
Accept-Languagerequest headers against the official ISO 639 registry, ensuring your API only accepts recognized language codes. - Library and archive systems: Use ISO 639-2 three-letter codes for bibliographic cataloging, metadata records, and digital library management in compliance with MARC and Dublin Core standards.
ISO 639 Standard Variants
The ISO 639 standard has several parts that serve different purposes. ISO 639-1 defines two-letter codes for the most widely spoken languages and is the format used in HTML, HTTP headers, and most web technologies. ISO 639-2 provides three-letter codes with broader coverage and comes in two variants: the bibliographic code (639-2/B) used in library systems and the terminological code (639-2/T) used in linguistic databases. ISO 639-3 extends coverage to all known human languages, including historical and constructed languages, using three-letter codes. This dataset focuses on 639-1 and 639-2 codes, which cover the languages most commonly needed in software development and content management.
How to Use in Your Application
Download the JSON format to create a language lookup service that resolves codes to display names in any application. The structured array is ideal for populating language selector components in React, Vue, or server-rendered templates. For database-driven applications, the SQL export creates a reference table you can foreign-key from user profiles, content records, or translation management tables. The CSV format is useful for spreadsheet-based translation project planning or for feeding into localization platform import tools. Use the native name column to display language names in their own script, providing a more inclusive user experience in language selection interfaces.
Language Families and Classification
Each language in the dataset is tagged with its language family, providing a hierarchical classification that groups related languages together. Major families include Indo-European (covering Romance, Germanic, Slavic, and Indo-Aryan branches), Sino-Tibetan (including Mandarin, Cantonese, and Tibetan), Afro-Asiatic (covering Arabic, Hebrew, and Amharic), and Niger-Congo (the largest family by number of languages, prevalent across sub-Saharan Africa). The family classification is useful for building language suggestion features, grouping related languages in user interfaces, and understanding script and directionality requirements when rendering text in multiple languages.