About ISO Language Code Lookup (ISO 639)
Comprehensive ISO 639 standard language reference directory. Look up 2-letter ISO 639-1 and 3-letter ISO 639-2 codes, English language names, native endonyms/autonyms (e.g. Deutsch, Español, 日本語, العربية), writing direction (LTR vs RTL), and language family classifications.
Key Capabilities & Features
- Comprehensive database of world languages with ISO 639-1 and ISO 639-2 codes
- Native script autonyms and endonyms for accurate international localization
- Text direction indicators (LTR vs RTL) for CSS dir="rtl" and bidirectional layout setup
- Language family classifications (Indo-European, Sino-Tibetan, Afroasiatic, etc.)
- Direct compatibility with HTML lang="" and BCP 47 internationalization standards
How to Use ISO Language Code Lookup (ISO 639)
Search Language
Search by English name, native autonym, or 2/3 letter code.
Verify ISO Format
Check the 2-letter ISO 639-1 code for HTML lang tags or 639-2 for bibliographic records.
Check Text Direction
Note whether the language requires Right-to-Left (RTL) styling.
Copy Language Code
Copy the code for your i18n localization dictionaries and HTML headers.
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100% Client-Side. Language code lookup queries operate locally in your browser.
Frequently Asked Questions
What is the difference between ISO 639-1 and ISO 639-2?
ISO 639-1 provides two-letter codes designed for terminology, HTML lang tags, and general computing. ISO 639-2 provides three-letter codes covering a much wider set of modern, historical, and ancient languages.
Which major world languages are written Right-to-Left (RTL)?
Arabic (ar), Hebrew (he), Persian/Farsi (fa), and Urdu (ur) are the primary modern languages written from right to left.