ISO 639 Language Codes

2026.1.31 · active · verified Thu Apr 09

python-iso639 provides a comprehensive and easy-to-use interface to ISO 639 language codes, including 639-1, 639-2, and 639-3, along with their names and associated information. It is actively maintained with frequent updates to the underlying ISO 639 data from SIL. The current version is 2026.1.31.

Warnings

breaking The `exact` keyword argument in `Language.match` was removed and replaced with `strict_case` in version 2025.11.11. The default behavior for case-insensitivity also changed.
Fix: Replace `exact=True` with `strict_case=True` (or omit as it's the default). Replace `exact=False` with `strict_case=False`. Note that `strict_case=True` is the default, making matching case-sensitive by default.
gotcha The default behavior for case-insensitivity in `Language.match` has changed multiple times. In 2025.2.18, case-insensitivity became the default. In 2025.11.11, it reverted to being opt-in (`strict_case=False`).
Fix: Always explicitly set `strict_case=False` if you need case-insensitive matching, or `strict_case=True` if you need case-sensitive matching (which is the default from 2025.11.11 onwards).
breaking Support for Python 3.9 was dropped in version 2025.11.11.
Fix: Upgrade your Python environment to 3.10 or newer.
breaking Support for Python 3.8 was dropped in version 2024.10.22.
Fix: Upgrade your Python environment to 3.9 or newer (or 3.10+ for the latest library versions).

Install

pip install python-iso639 Install stable release

Imports

Language
```
from iso639 import Language
```
languages
```
from iso639 import languages
```

Quickstart

This quickstart demonstrates how to import the `Language` class and `languages` collection, query languages using ISO 639-1 and 639-3 codes, and search for languages by name with case-insensitivity.

from iso639 import Language, languages

# Query a language by its ISO 639-1 code
english_lang = Language.from_part1("en")
print(f"639-1 'en' name: {english_lang.name}")

# Query by ISO 639-3 code
japanese_lang = Language.from_part3("jpn")
print(f"639-3 'jpn' name: {japanese_lang.name}")

# Get all languages
print(f"Total languages in database: {len(languages)}")

# Search languages by name (case-insensitive, strict_case=False)
spanish_languages = languages.match("Spanish", strict_case=False)
print("Matching 'Spanish' (case-insensitive):")
for lang in spanish_languages:
    print(f"- {lang.name} ({lang.part1 if lang.part1 else lang.part3})")

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